The world is undergoing an energy transformation, with renewable sources gradually replacing fossil fuels. Hydrogen is a promising alternative, but current production methods are either carbon-intensive or inefficient. This project introduces a novel photothermal-assisted solar water splitting system that integrates a patent-pending plasmonic metasurface electrode to produce hydrogen directly from sunlight. Unlike conventional systems, our approach utilizes the full solar spectrum to create electricity and heat at the nanoscale, which drive the hydrogen producing water splitting reaction. Our tightly integrated system eliminates bulky optical and thermal components, radically reducing system complexity and cost. This is possible due to the unique properties of our metasurface electrode that achieves 60× higher sunlight absorption per unit thickness than comparable photothermal technologies and that can be fabricated using industry-standard, low-cost processes. In this project we aim to integrate our state-of-the-art photothermal metasurface into a scalable solar water splitting system to increase the solar-to-hydrogen (STH) efficiency to more than 15%, which would make green hydrogen cost-competitive with fossil fuel-based approaches.

Advancing organic semiconductor (OS) heterojunctions for solar fuel production, particularly focusing on improving their long-term stability and performance, holds promise to make them viable candidates for inexpensive solar-driven hydrogen production on a global scale, however significant development remains required. The main goals of the project are to gain fundamental understanding of the stability limitations in bulk heterojunction (BHJ) OS photoelectrodes, to tune interfaces in BHJ photoelectrodes for enhanced stability, and to develop molecularly engineered OS materials with improved stability in aqueous environments. The project goals exceed the state of the art by addressing the critical challenge of long-term stability in OS-based solar fuel production systems, which has been a major bottleneck in their development and is typically ignored by current research efforts. Moreover, the project will answer fundamental questions not addressed by the research community on BHJ operation and degradation such as: What are the limits of BHJ operation under idealized conditions? Where is degradation occurring and which reactions lead to performance decrease? How does water/ion infiltration affect BHJ component crystallinity and photocurrent degradation during operation? The project aims to achieve unprecedented operational lifetimes of at least 1000 hours with less than 20% loss of initial photocurrent for overall solar-driven water splitting using a photoanode/photocathode tandem cell, which is an ambitious but reasonable goal, and sets the stage for the translation of the technology developed herein to economically appealing nanoparticle photocatalyst systems. The research approach is divided into two work packages (WPs) where WP1 focuses on understanding stability limitations and WP2 aims to engineer interfaces and materials for enhanced stability. Specific goals in WP1 are the development of a high-throughput long-term photoelectrochemical (PEC) measurement system to test the specific effects of environmental conditions (including dissolved oxygen concentration), employing advanced electrochemical impedance spectroscopy (EIS) and intensity modulated photocurrent spectroscopy (IMPS) techniques with a new distribution of relaxation times (DRT) analysis, conducting post-mortem analysis via a recycling method that can also serve to improve scalability and reduce the costs of employing OSs, and examining water and ion infiltration in situ. In parallel, WP2 will investigate bilayer heterojunction photoelectrodes that have decreased disorder and likely less water infiltration, developing self-assembled monolayer (SAM) interlayers to enhance interfacial stability, establishing covalent linking of co-catalysts via photodeposition for robust inorganic/organic connectivity, and implementing molecular engineering strategies on polymer OSs for improved stability. The implementation of the work involves a systematic approach, starting with simple PEC model systems for rapid feedback and progressing to more complex engineered materials while ensuring that the materials and processing conditions are translatable to nanoparticle photocatalyst (PC) systems, which are considered more promising for economically viable hydrogen production. While the project is designed to provide fundamental insights into OS-water interfaces it also addresses practical challenges in solar fuel production. The interdisciplinary nature of the research, combining organic chemistry, semiconductor physics, and electrochemistry, is expected to yield broadly applicable insights and methodologies. By focusing on scalable, solution-processable materials and techniques, the project aims to ensure that its outcomes can be readily translated to industrial applications. This approach could potentially accelerate the commercialization of OS-based solar fuel technologies, contributing to the transition towards sustainable energy systems.

The present proposal tackles some of the most pressing challenges of our time, by introducing a general approach to design environmental remediation strategies for the mitigation of climate change and the circular economy of water. The overarching idea of the proposal is to use food protein amyloids sourced from food waste and food industry side streams as main building blocks for the intended technologies, therefore offering remediation strategies operating with only minimal carbon footprint in water purification, CO2 capture/conversion and clean H2 production for zero-emission energy technologies (e.g. fuel cells). Specifically, amyloid fibrils derived from proteins extracted from industrial side-streams such as in soy, dairy, and oilcrop industries, will serve simultaneously as templates (for the synthesis) and scaffolds (for the support) for organic-inorganic hybrid catalysts based on single-site, nanoclusters and nanoparticles. These scaffolds/templates will be engineered in the forms of amyloid hydrogels/aerogels/membranes which will then be functionalized by the inorganic catalysts by impregnation techniques or in-situ green synthetic strategies. The resulting hybrid catalysts will operate by electrochemical, photochemical and thermochemical heterogeneous catalysis in three working packages corresponding to three distinct PhD theses, each focusing on either: i) water purification from organic pollutants, ii) CO2 reduction into valuable compounds and iii) H2 production by water splitting. In the first WP/PhD we will target organic chemical compounds occurring in wastewater such as pesticides, PFAS and antibiotics which will be catalytically degraded into less harmful compounds first by lab-scale model reactions, and then via a newly designed photocatalytic reactor prototype. In the second WP/PhD, CO2 will be reduced into useful chemical compounds such as alcohols, oxygenates, and hydrocarbons; Finally, the third WP/PhD will produce clean H2 by hydrogen evolution reactions following photocatalytic and electrocatalytic processes scalable into industrial electrolyzer systems. By repurposing food waste into versatile amyloid materials which play the double role of templates and scaffolds for hybrid catalytic materials, this proposal aims at designing close-to-zero carbon footprint environmental technologies, which may also address some of the classical drawbacks of traditional heterogeneous catalysis, in particular, by allowing a transition from batch catalysis to continuous catalysis.

Imaging of biological and non-biological materials in all fields of research relies on cutting edge sample preparation technologies. This is particularly true for combining various X-ray and EM-based imaging and diffraction methods, with different dimensions and spatial resolution. For X-ray imaging, sample preparation involves thinning of bulky specimens to <100 um pillars. For EM-based imaging approaches, um-scale objects must be thinned to 10-200 nm thin lamellae to allow electrons to permeate the volume of the material. To enable advanced analysis of hard materials, soft organic materials and biological samples by X-ray imaging and electron microscopy (EM) there is a need to implement a focused ion beam scanning electron microscope (FIB-SEM) instrument capable of thinning samples of large volumes while providing the required precision. For studies of crystalline or non-crystalline radiation sensitive materials, both in materials science and in biology, the milling instrument must be equipped with a cryo-stage and a transfer system to safely handle the specimen. The use of plasma (Xe-ions or other atomic species) will allow for fast milling of large sample volumes without chemical reactions with the sample material. The downstream applications will depend on the specific projects and samples of interest, in materials and life science, and will range from EM, cryo-EM (cryo-electron tomography) to electron diffraction and X-ray tomography. Here we propose to establish a state-of-the-art cryo-PFIB-SEM platform at the Paul Scherrer Institute, necessary to prepare hard and soft material samples, in order to address the needs of some of the most challenging projects aiming at high-resolution investigations using both X-ray imaging and EM-based approaches. The instrument essential for utilizing the unique capabilities of PSI in X-ray imaging, allowing us to develop new state of the art approaches for correlative imaging of diverse specimens by X-rays, visible light and electrons. The ideal instrument will be equipped with a plasma source (Xe, O, Ar, N) for rapid removal of the matter, enabling FIB-milling and SEM imaging at ambient or cryogenic temperature. Additionally, a room temperature and cryo-lift-out capability for micromanipulation of the sample of interest, combined with shuttles to take out milled specimen either under cryo-temperature or in inert gas atmosphere will be an essential part of the instrument. An integrated light microscope will be necessary for correlative imaging of biological specimens. The instrument will be located at the Paul Scherrer Institute and will be integrated in the instrument park of the PSI EM facility.

The electrolysis of water for hydrogen production and subsequent electricity generation from the accumulated hydrogen using fuel cells is a promising direction in renewable energy. Solid oxide fuel cells (SOFCs) and electrolyzers (SOEs), operating above 300 °C, demonstrate rapid electrode kinetics, particularly proton-conductor-based SOFCs (PCSOFCs). However, such fuel cells are limited in long-term stability due to thermal stress. Ceramic devices operating between 150-250 °C could exhibit rapid electrode kinetics, even without Pt-based catalysts, yet avoid damage from thermal stress. Unfortunately, ceramic proton conductors (PrCs) capable of operating in this temperature range have not been identified to date. We propose a basic science research project aimed at identifying and characterizing the causal relationship between local structure and the dynamics of protons in the lattice of hydrated --/ (LCO), with or without co-doping. To this end, we shall investigate the following: (i) the location of protons in the LCO crystal lattice; (ii) the dynamics of protons in LCO (i.e., proton-phonon coupling) , including determining the enthalpy of binding of the protons as well as identifying descriptors (factors) that define proton mobility as a function of composition; (iii) dependence of the hydration process on grain size and the structure of grain boundaries. Achieving these goals will lead to the development of a strategy to maximize proton conductivity in LCO-based ceramics and thin films. The project aims to provide essential information about the local structure of hydrated fluorites and pyrochlores, data which are currently unavailable, and to broaden the horizon for the development of proton-conducting ceramics. This, in turn, opens up new perspectives in hydrogen technology and renewable energy based on electrolyzers and PCSOFCs operating below 200 °C. Moreover, LCO ceramics are suitable for microfabrication and are also biocompatible, presenting potential application in portable electronics and implantable fuel cells. The project will utilize innovative ceramic hydration methodology, based on a purpose-designed hydration chamber (Israeli PI), and state-of-the-art structural analysis methods (Swiss PI). Since the positions of protons in a crystal lattice are not detectable by commonly used techniques (X-ray diffraction, X-ray absorption spectroscopy, or NMR), we will leverage the expertise of the Swiss PI in neutron diffraction (ND) and inelastic/quasi-elastic neutron scattering (INS, QENS) for studying ceramic proton conductors. The division of work will capitalize on the complementary expertise of the PIs, who have had a mutually productive collaborative experience during the Swiss PI's sabbatical in the laboratory of the Israeli PI. Preparation of ceramics and thin films and their electrical characterization will be conducted at WIS. Hydration (or deuteration) will also take place in Israel, with an effective arrangement for similar processing just prior to measurement at the neutron sources. Neutron diffraction/scattering experiments will be carried out by the Swiss team, with participation of students from the Israeli group. Preliminary experiments demonstrate that LCO ceramics with high levels of hydration (˜ 40%) can be prepared without mechanical disintegration, while electrical measurements suggest proton mobility upon hydration.

This research project seeks to advance our understanding of catalyst stability during various electrochemical reactions, potentially leading to more efficient and durable catalysts for important chemical processes. The aim is to comprehensively address stability concerns through advanced catalyst synthesis strategies. This will be linked with the development and refinement of experimental methods and electrocatalyst analyses, with particular emphasis on in situ and operando techniques. Last but not least, we will apply machine learning strategies for guiding the synthesis as well as to develop experimental and computational models in a data-driven approach. The imminent goal is to reduce or replace the use of scarce platinum group metals (PGMs in the respective processes. On a broader scale, the obtained experimental results will improve our theoretical understanding of catalyst stability and help to develop theoretical models for catalyst degradation, eventually contributing to establishing a descriptor-based approach to catalyst stability. In the proposal, we address three essential energy conversion reactions, the oxygen reduction reaction (ORR), the oxygen evolution reaction (OER), and the selective glucose oxidation reaction (GOR). Oxygen Reduction Reaction: This reaction is the limiting process for hydrogen fuel cells and currently Pt-based catalysts are state-of-the-art. The project focuses on Pt-based, compositionally complex solid solution nanoparticles. The goal is to explore the stability of these catalysts during the acidic ORR with a focus on compositional and structural changes of the active phase. The investigations will involve the use of in situ and operando XAS, SAXS, XRD, and total scattering measurements. The work constitutes work package one (WP1). It will be executed by one PhD student (48 months), and a Postdoctoral researcher (24 months) employed by Prof. Rebecca Pittkowski at the University of Copenhagen. Several visits of the Postdoctoral researcher and PhD student between the University of Copenhagen and the University of Bern are planned. Oxygen Evolution Reaction: The oxygen evolution reaction is the limiting reaction for water electrolysis providing green hydrogen, which is the starting point for sustainable chemicals and fuels. The lack of stable, active, and scalable catalysts for the OER under acidic conditions is one of the most important challenges for electrocatalysis today. In the project, we focus on MnOx-based catalysts. The primary objective is to examine doping approaches as well as introducing structural barriers to metal dissolution during the OER. This part constitutes WP2 and will be executed by one PhD student who will benefit from the work of the Postdoctoral researcher employed in WP1. Selective Glucose Oxidation Reaction: The third part of the project, WP3, concentrates on the selective GOR using both Au-based compositionally complex solid solution nanoparticles and porous metal foams as catalysts. The main emphasis here is to investigate the mechanisms behind catalyst degradation, specifically related to metal dissolution and side product formation. By gaining insights into these degradation mechanisms, the project aims to enhance the stability and longevity of these catalysts. WP3 will be executed by one PhD student. The closely related topic will allow synergetic effects with the work in WP1 and WP2.

Renewable energy solutions have witnessed growth in the past decade because of increasing global energy demand and environmental pollution caused by fossil fuels. A renewables-based hydrogen economyy is a promising route. In this route fuel cells are a pivotal component. Considering the transport sector, fuel cell vehicles (FCVs) are critical and expected to reduce emissions to near zero when hydrogen is produced from renewables. Different from batteries fuel cells are energy conversion devices that use hydrogen to store energy. From a storage-only perspective the latter has higher energy density and shorter refuelling times. Furthermore, they outperform the former under sub-zero temperature conditions. While FCVs currently come with higher cost compared to battery electric vehicles, their overall operation cost is expected to reduce considerably partly with expanding infrastructures both for hydrogen production and distribution. Hydrospider in Switzerland uses the energy produced by the Gosgen hydroelectric plant to produce hydrogen via electrolysis. A couple of filling stations in Hunzenschwil and St Gallen are already active and a few hundred planned by 2030 in the context H2Mobility project. Another aspect that needs consideration to reduce FCVs cost is technical barriers to improve performance and durability of Proton-Exchange Membrane Fuel Cells (PEMFC). Improving power density is vital for the development of FCVs. For instance the European Union Fuel Cells and Hydrogen 2 Joint Undertaking is targeting a power density of 9.3 kW/l. Improvements in PEMFCs needed to achieve future high power-density requirements include, but are not limited to, catalyst activity and catalyst layer design, improvement of proton conductivity of proton-exchange membranes under low humidity, mass transport capacity increase in bipolar plates and optimization of gas diffusion layer design for both water management and gas permeation. Direct numerical simulations are widely adopted as non-invasive, reliable and cost-effective tools to study and optimize complex industrial systems. Here we intend to develop multicomponent and multiphase lattice Boltzmann models with detailed electrochemistry, mass transport and fluid dynamics for thermodynamically consistent transient simulations of realistic fuel cells. Such a solver would not only reveal the rich interplay between chemical reactions, fluid flow, species composition and current density but also function as a digital twin for developing and optimizing practical fuel cells at a reasonable compute cost. The recent developments in the LBM for multicomponent, reactive and multiphase flows and the innate ability of the method to capture Knudsen effects due to its kinetic nature make it an excellent fit for modelling fuel cells. The work will involve development of a Dusty Gas Model from the Stefan-Maxwell model, development of porous media non-isothermal hydrodynamics models, models for migration of ions through solid electrolytes, detailed chemistry models for adsorption-desorption and electrochemistry at the triple phase boundary, full cell multicomponent simulations with resolved as well as averaged electrode microstruture and multiphase DNS simulations for studying drainage in resolved microstructure geometries. Extensive validation with existing numerical and experimental results will be performed. The project is expected to yield scientific and practical gains: A new class of LBMs for reactive hydrodynamics and diffusion in porous media as well as for solid media thermal and ion diffusion, providing additional insights into flow, composition and temperature fields in typical fuel cells improving our knowledge of physical and chemical processes occurring there. A computing framework capable of performing realistic scale simulations opening up interesting opportunities for optimizations pertaining to geometry, operating conditions, fuel composition, internal reforming, etc.

The waste-water treatment engenders significant energy drain; it requires up to 3% of the total electrical energy output, which is an enormous amount when global production of 330 – 390 km3 /year municipal waste-water is considered. The recoverable potential energy in municipal waste-water could be thermodynamically estimated as 8 047 kJ/m3 × 360 km3 /year = 2.90 × 1015 kJ/year globally, equivalent to 805 billion kWh of electricity per year. The potential energy in municipal waste-water is comparable to bio-power, accounting for about 8.53% of global renewable energy. This prioritises the water-energy nexus, requiring technologies to support the water cycle's sustainability. Direct capture of the energy in municipal waste-water will have a positive impact on reduced energy costs and reduce greenhouse gas emissions, altogether supporting the goals of the Paris Agreement toward climate mitigation through waste-water management. One rapidly developing biotechnology focusing on waste-water management with concomitant energy production are microbial fuel cells (MFCs). They are bio-electrochemical systems that combine biological and electrochemical processes to generate electricity, hydrogen, chemicals and metals (methane, H2O2, gold, copper) while purifying waste-water. Theoretically, a single model microbe cell with a volume of 0.491 µm3 has the potential to produce ca. 16 000 kW m-3.4 Depending on energy gain by the bacteria and the loss of energy at the cathode, a voltage between 0.3 V and 0.5 V is usually obtained when using fuels such as glucose and acetic acid. Currently, the maximum power densities that microorganisms are by theory capable of producing have not yet been reached! MFCs utilise the bio-catalytic capabilities of viable microorganisms to oxidise biomass and organic matter into bioelectricity. Using bacteria or a consortium of bacteria as a catalyst provides the possibility of employing a wide range of microbial degradable organic or inorganic matter such as dyestuff waste, municipality waste, organic waste, soil sediments. In contrast to acidic and alkaline fuel cells, MFCs can operate under mild conditions (low temperatures, neutral pHs). They incorporate the metabolism of whole organisms to generate electricity either directly (i.e., metal-reducing bacteria such as Geobacter sp., Rhodoferax sp., and with the aid of secreted mediators in the Shewanella sp.) or indirectly (biological fermentation of carbon sources to hydrogen with Escherichia sp. or Clostridium sp.) from indigenous nutrients. The development of a bio-potential due to the microorganism's metabolic activity in the anodic compartment (i.e. reduction reactions, generating both electrons and protons) and electron acceptor conditions in the cathode leads to the generation of bioelectricity in MFCs. The proton exchange membrane (PEM) is a central MFC component that separates MFC compartments, transfers protons from the anode to the cathode, and prevents substrate leakage and oxygen crossover between the electrodes. Protons produced by active bacteria at the anode diffuse through a PEM into the cathode compartment, so the membrane needs to provide excellent proton-transport ability. Oxygen is primarily used as the oxidant in the cathode compartment due to its abundance and high reduction potential. Diffused protons combine with oxygen, generating water. The operation of PEMs is one of the most crucial factors in MFC performance as it has a significant impact on both the performance (e.g. coulombic efficiencies and internal electrical resistance) and the capital costs.

The concept of artificial photosynthesis, expressed about 100 years ago by Chemist Ciamician, is currently experiencing a revival. The fields of artificial photosynthesis for solar fuels and photovoltaics for solar electricity have developed at large in parallel and independently. The former is lagging behind as far as the technology is concerned, but it keeps greater promise because it can theoretically satisfy the world’s need for fuels, which amounts to 80% of the current world energy consumption. Employing biological components for solar energy conversion has been under scrutiny for a long time. Implementation of the biological photosynthesis apparatus in solar energy conversion technology is now of interest. This is because biological components can in principal be grown at low cost and because they can rejuvenate eternally by biological reproduction. Currently there is great interest in making bio-hybrid electrochemical devices and understanding the physical and chemical interactions between the animate and inanimate matter components at the molecular scale. Semiconductor electrodes will be instrumental for the future artificial photosynthesis apparatus because it provides the electric and ionic nexus between the bi-ological photosynthesis components and the readily existing electrical engineering infrastructure in the build environment. We develop a cyanobacteria (algae) based bio-photoelectrochemical reactor with 3D printing technology for solar electricity and hydrogen production. Much of the energy available on Earth (except for natural nuclear energy from the Earth core originates from the sun, resulting into primary production and hu-man civilization. Over 80% of world energy consumption is based on fuels (biomass, fossil, nuclear), less than 20% come in form of electricity incl. hydrocarbon fuel production with CO2 reduction. A hybrid concept uses functionalization of electrodes with components from photosynthesis, or with living cells, such as cyanobacteria. As the latter are alive, one could take advantage of their biological repair systems and their population dynamics.Essential functional components for this 3D printed reactor are the electrode support respectively the current collector material and potential redox active inorganic layer, the type of cyanobacteria (algae), and the 3D electrolyte matrix which also should contain nutrients for algae. We know promising materials to start with, notwithstanding potential for optimization by synthesis, processing and operation parame-ters as well as choice of better alternatives for the components.We design, fabricate and analytically investigate an electrode assembly prepared from a semiconductor photoelectrode, coated with a 3D printed functional algae layer on top. The metabolism of the algae will be diverted and exploited for the production of hydrogen or hydrocarbon fuel so as to generate solar fuels and reduce carbon dioxide from concentrated sources, or from the ambient environment.This new technology will support numerous national and international science programs and policy to-wards the limitation of the production of new CO2, which comes with utilization of fossil fuels, inclusion for a renewable energy strategy for solar hydrogen or other solar fuels Hurdles are the separation of each cyanobacterium towards external environment, because a thick layer of cyanobacteria must be electrophysiologically connected so as to warrant charge and mass transport between semiconductor and cyanobacterium, and cyanobacterium to electrolyte, and potentially among the cyanobacteria as well. Particularly the electrical and chemical communication among this ensemble must be comprehensively addressed. Further issue in this context is the formulation of an ink made from cyanobacteria, which supports the aforementioned function and can be applied with a 3D printer.

Anthropogenic climate change adversely affects life on Earth and has negative environmental, economic and societal impacts. To counteract global warming, fossil fuels will have to be phased out as energy carriers and feedstocks for the chemical industry. As an alternative to fossil fuels, sustainably produced methanol can be used for numerous applications. Green methanol can be synthesized from biomass (bio-methanol) or from captured carbon dioxide or methane using renewable electricity (e-methanol). Its production has recently reached commercial scale and is projected to expand rapidly in the coming years. When used in bioconversion processes, green methanol enables the generation of carbon-neutral or even carbon-negative products. Additionally, such bioprocesses are independent from human food and animal feed production and require less water, nitrogen, as well as land than conventional, sugar-powered biotechnology. However, natural methanol-metabolizing organisms, known as methylotrophs, have proven challenging for use in industry and alternative, novel, biocatalysts must be developed. In this project, we aim to establish synthetic methylotrophy as a new mode of bioproduction. Major goals of the project include the establishment of a genetically defined and stable chassis strain, the production of industrially relevant chemicals and high cell density cultivation in bioreactors to enable industrial bioprocesses. Industrial application of synthetic methylotrophy will bridge the gap between captured greenhouse gases and value-added products and will contribute to a viable strategy for green methanol and, ultimately, greenhouse gas valorization.

A major challenge for our society is to ensure access to reliable energy with low impact on the climate and the environment. To this end, sustainably produced hydrogen (H2) is an alternative to the fossil fuels used today, emitting carbon dioxide. However, the use of H2 as a fuel requires the adaptation of current combustion chambers in order to maximise efficiency, limit the emission of nitrogen oxides (NOx), and ensure safety. NOx emission regulations require the use of lean or ultra-lean premixed combustion for H2, which raises ignition and flame stability issues. The objective of this project is to develop the use of plasma discharges in H2 mixtures, an excellent candidate to i) guarantee a timely ignition after H2 injection in the combustion chamber, and ii) control combustion instabilities.Over the last twenty years, Non-Equilibrium Plasma (NEP) discharges including Nanosecond Repetitively Pulse Discharges (NRPD) have been studied by the scientific community to control combustion in hydrocarbon-air mixtures. Many works now demonstrate their ability to sustain lean combustion and mitigate combustion instabilities. NRPD can also be used to ignite a mixture effectively without large heat deposition, by generating reactive radicals that will initiate the oxidation of the fuel at low temperature. This ensures smooth and reliable ignition of combustible mixtures, without too high pressure rise and risk of detonation.Although the NRPD efficiency has been evidenced for hydrocarbon mixtures, their use in complex systems fully or partially fed with H2 is yet to be investigated. Based on experiments conducted at ETH Zürich and numerical simulations conducted at CERFACS, both fundamental and practical research questions will be investigated. First, the effects of NRPD discharges in H2-containing mixtures will be established in a canonical channel flow configuration. Based on this knowledge, we will design the discharge parameters in order to optimise the ignition by radical generation from the plasma. We will then study both experimentally and numerically the effects of NRPD discharges in a realistic complex configuration, close to an industrial system. Both the smooth ignition and the control of combustion instabilities will be investigated. The 3-dimensional computations of the configurations will provide essential information for the understanding of the associated physics. New phenomenological models for plasma physics will be derived to make the computation of such complex configurations possible, overcoming the huge cost of fully coupled plasma-combustion simulation.This research project will provide knowledge for the design of NRPD systems, leveraging the combustion of hydrogen in lean regimes to allow the use of this carbon-free fuel in combustion systems. For this reason, the project has the potential of a very strong impact on the energy production and transport industry.

The gradual transfer from natural gas to hydrogen in the economy can be simplified by using the existing fuel infrastructure. Relevant to the prevention of the freeze-out of condensable compounds from natural gas, surface phenomena, solubility and diffusivity of the dissolved gas will be altered upon the change of gases. Hydrogen can be stored and transported using Liquid Organic Hydrogen Carriers (LOHCs); the knowledge of their properties when in contact with pressurized hydrogen however remains, however, largely limited. We propose to study the properties of liquids relevant for the processing of methane, ethane and hydrogen under relevant conditions. Surface tension, gas diffusivity, solubility and liquid swelling will be studied by the 2nd generation of our novel one-pot neutron imaging method [PLoS ONE 15(9), 2020, e0238470] enabling the in-situ time-resolved observation of pressurized liquids with a sub-100 µm spatial resolution utilizing the high protium to deuterium neutron contrast. Molecular dynamics simulations will be performed to assess the mentioned properties in-silico and -after referencing with the experimental results- will lead to the result extrapolation for even wider range of industrially relevant but experimentally hardly accessible conditions.

Photocatalytic sheets have disruptive potential in the field of sustainable hydrogen production. The main aim of this proposal is to demonstrate the translation from photoelectrochemical (PEC) thin film water splitting systems to photocatalytic (PC) sheets. Our prior work involving practical synthesis methods and advanced characterization techniques of thin film photocathodes and photoanodes will enable us to find the right materials combination as well as suitable ordering of synthetic steps to fabricate overall water splitting photocatalytic sheets with practically attainable solar-to-hydrogen (STH) efficiencies of 2.5%, a large improvement over the current record of 1.1%. Such a demonstration would heighten industrial interest in this emerging field. Two PC sheet architectures are targeted, based on the thin film electrodes that are investigated: Sb2Se3/BiVO4 and Cu2O/BiVO4. The proposal is divided into two work packages (WPs). In WP1, Sb2Se3, Cu2O, and BiVO4 thin films are investigated with two main goals: 1) to improve the performance of thin film-based systems with novel strategies that target both the interface and bulk material, and 2) to readily assess the effects of different treatments (e.g., etching, overlayer deposition) that will be required at the PC sheet stage of the project for maximizing their efficiency and durability. It is difficult to identify the precise source of poor performance in particle-based systems, but we have an arsenal of techniques to effectively diagnose even very complex thin film electrodes, which enables knowledge transfer to optimize the PC sheets. In WP2, Sb2Se3, Cu2O, and BiVO4 are investigated as PC sheets, first as single materials and then in combination with each other. Sb2Se3/BiVO4 can be prepared in relatively few steps since the Sb2Se3 does not strictly need corrosion-protection overlayers. After gaining experience with this simple system, we will turn our attention to Cu2O/BiVO4, which requires several additional steps for improved durability, but for which the demonstrated (thin film) performance is already sufficient to yield a 2.5% efficiency PC sheet (with similar quality particles). The optimal ordering of synthetic steps for fabricating the PC sheets is not a priori clear, and therefore studies on the thin film electrodes will be invaluable for quickly assessing the impact of individual synthetic steps on both materials, whereas each synthetic treatment is typically for the benefit of only one particle.The work proposed herein will demonstrate the utility of intimate knowledge transfer between thin film PEC systems and PC sheets, yielding rapid improvement in PC sheet performance. Moreover, it will encourage other researchers who focus on thin films to step into the important field of PC sheets, which have a much higher potential for disruption in the field of solar fuels.

As climate is threatened by CO2 emissions from our fossil fuel-based economy, CO2 emissions must be cut and fossil fuels replaced. Green hydrogen is a promising energy vector for this purpose but its long-term storage and transportation is difficult. Instead, it can be converted to green liquid ammonia for easier handling and transport. The infrastructure for the large-scale production of ammonia at the million-ton level already exists, since ammonia is the second most-produced chemical in the world, acting as a building block for various chemicals. However, it is expected that wind and photovoltaic (PV) energy for water electrolysis to green hydrogen will be produced dispersed in remote places. Therefore, reactor concepts for the small-scale synthesis of ammonia at the place of power generation are urgently needed. The liquid ammonia produced in this way can be easily transported.The overall objective of this research project is to develop in a scientific bottom-up approach a breakthrough process for efficient decentralized production of green ammonia as a long-term storage for hydrogen at lower energy cost than the conventional methods. To this end, we will combine the following three concepts for the generation of green ammonia: 1) process intensification (in-situ ammonia removal by sorbents to go beyond the static equilibrium), 2) electrification (induction-based catalyst materials, powered by renewables), and 3) modularity. We will start with ruthenium-based catalysts due to their literature-known suitability for ammonia synthesis under mild conditions, but search for the optimal catalyst composition will be supported by a first-principles (density functional theory - DFT) computational catalyst screening based on the underlying atomistic level understanding of the process. Ru-doped pyrochlore and perovskite solid solutions will be prepared from which Ru nanoparticles will be generated by reductive exsolution. The Ru-based catalyst will be coupled with magnetic susceptors for inductive heating to boost ammonia productivity while lowering energy requirements. Supported metal halides will be developed as selective absorbent materials for in-situ ammonia separation from the effluents to drive the reaction beyond thermodynamic equilibrium limits. The combined catalyst-absorbent system will be used together with the inductive heating to test the feasibility of the reaction concept. Advanced characterization tools will be applied to establish a comprehensive structure-performance relationship for the developed materials. Based on the characterization data, a digital twin of the process will be programmed by modeling the relevant phenomena at all length scales, from the atomistic level up to the reactor scale. The digital twin will be used to design and optimize the reactor under dynamic conditions at the end of the project.The project will be conducted by the Group of Catalysis for Biofuels at EPFL, headed by Prof. Oliver Kröcher, and the group of Prof. Blaž Likozar, at the National Institute of Chemistry (NIC) in Slovenia. Prof. Oliver Kröcher will work together with Dr. Awais Naeem, an experienced material scientist in his research group, and one PhD student on the development of the catalyst, ammonia sorbent and inductively heatable material, whereas Prof. Blaž Likozar will work with Dr. Matej Huš (first-principles modeling specialist) and a new PhD student to provide the DFT calculations for the catalyst screening, the development of the digital twin and the model-based optimization of the process. Both groups will closely collaborate on the project according to their respective strengths and expertise. Namely, the reaction design at NIC depends on the characteristics of the developed materials at EPFL, which in turn are tailored based on the predictions of the DFT calculation at NIC, the results of the catalyst screening and the requirements of the process conditions. Hence, a constant interaction between both partners will be an integral part of the proposed project.Based on the timeliness of the topic (climate and energy crisis), the innovative research approach (model-guided catalyst discovery and inductive heating), the sound research plan and the expertise of the involved research groups, we are certain that the project will have a significant impact on both the advancement of science in the addressed fields and the supply of energy in a future renewable energy system.