Publications

The effects of climate change and reliance on fossil fuels in the Alps highlight the need for energy sufficiency improved efficiency and renewable energy deployment to support decarbonization goals. Hydrogen has gained attention as a versatile zero-emission energy carrier with the potential to drive cleaner energy solutions and sustainable tourism in Alpine regions. This study shares findings from a hydrogen survey conducted within the Interreg Alpine Space AMETHyST project which included questionnaires and roundtable discussions across Alpine territories. The survey explored hydrogen’s role in decarbonizing the Alps gathering insights from local stakeholders about their knowledge expertise needs and targets for hydrogen solutions. It also mapped existing hydrogen initiatives. Results revealed strong interest in hydrogen implementation with many territories eager to launch projects. However high investment and operational costs along with associated risks are key barriers. The absence of clear local hydrogen strategies and of a comprehensive regulatory framework also poses significant challenges. Incentivization schemes could facilitate initiatives and foster local hydrogen economies. The most promising application areas for hydrogen in the Alps are private and public mobility sectors. The residential sector particularly in tourist accommodations also presents potential. Regardless of specific uses developing renewable energy capacity and infrastructure is essential to create green hydrogen ecosystems that can store excess renewable energy from intermittent sources for later use.

The erosion behavior and the service life of a hydrogen transmission tube with high velocity suitable for a hydrogen fuel aviation engine are not clear which is the bottleneck for its application. In this study a coupled model considering the fluid flow field of hydrogen and discrete motion of particles was established. The effects of the geometry parameters and erosion parameters on the hydrogen erosion behavior were investigated. The maximum erosion rate increased exponentially with the increased hydrogen velocity and increased linearly with the increased erosion time. The large bend radius and inner diameter of the bend tube contributed to the decreased erosion rate. There was an optimized window of the bend angle for a small erosion rate. The relationship between the accumulated thickness loss and maximum erosion rate was established. The prediction model of the service life was established using fourth strength theory. The service life of the tube was sensitive to the hydrogen velocity and erosion time. The experiments were conducted and the variations in thickness and hardness were measured. The simulated models agreed with the experiments and could provide guidance for the parameter selection and prediction of the service life of a bend tube.

Metal oxides (e.g. SnO2 ZnO TiO2) have been widely investigated materials for gas sensing applications including hydrogen detection. However the potential for hydrogen sensing of metal oxides such as CuO In2O3 NiO exhibiting p-type conduction has been largely overlooked. Over the last 15 years structures based on TiO2 and CuO have gained increasing interest as a promising system for hydrogen detection. Therefore this article aims to: 1) provide an overview of the performance of TiO2 as a reference material and discuss methods to enhance its sensing performance 2) summarize and highlight the role of copper oxides in hydrogen gas detection as the materials that have predominantly been studied for H2S detection 3) review efforts made to improve the sensing performance of heterostructures of CuTiOx from structures with charge compensation effect to those successfully sensing hydrogen 4) present the potential of CuTiOx for H2 detection.

In recent years governments have promoted the shift to low-emission transport systems with electric and hydrogen vehicles emerging as key alternatives for greener urban mobility. Evaluating zero- or near-zero tailpipe solutions requires a Lifecycle Assessment (LCA) approach accounting for emissions from energy production components and vehicle manufacturing. Such studies mainly address Greenhouse Gas (GHG) emissions while other pollutants are often overlooked. This study compares the Human Toxicity Potential (HTP) of Battery Electric Vehicles (BEVs) Fuel Cell Vehicles (FCVs) Hydrogen Internal Combustion Engine Vehicles (H2ICEVs) and hybrid H2ICEVs for public transport in the European Union. Current and future scenarios (2024 2030 2050) are examined considering evolving energy mixes and manufacturing impacts. Results underline that BEVs are characterized by the highest HTP in 2024 and that this trend is maintained even in future scenarios. As for hydrogen-based powertrains they show lower HTPs similar among them. This work underlines that current efforts must be intensified especially for BEVs to further limit harmful emissions from the mobility sector.

Hybrid water electrolysis system was designed by using Ruthenium-Tin Oxide (RuSn12.4O2) electrocatalyst as anode material for efficient hydrogen production enhancing energy conversion efficiency. The RuSn12.4O2 Electrocatalyst was synthesized by hydrothermal method and exhibited exceptional activity making it an optimal choice for Iodide oxidation reaction (IOR) and enabling energy-saving hydrogen production. The two-electrode acidic electrolyzer reduced voltage consumption by 0.51 V at 10 mA cm-2 compared to oxygen evolution reaction (OER) at the same current density. This hybrid electrolysis system achieved a remarkable reduction in energy consumption of over 40 % compared to OER process. The Chrono-potentiometric test demonstrated that the RuSn12.4O2 electro-catalyst’s superior stability and low overpotential increase of 70 mV at 10 mAcm-2 . The RuSn12.4O2 electro-catalyst Tafel slope is also a crucial metric for understanding kinetic characteristics in both IOR and OER processes. Thus RuSn12.4O2 electro-catalyst in IOR has a lower Tafel slope (61 mV dec-1) than that in OER according to the Tafel slopes determined from linear sweep voltammetry (LSV) curves. Additionally at various potentials the electro-catalyst's activity toward IOR to produce hydrogen demonstrated exceptional performance in this electrolysis system without causing any catalyst degradation.

Energy in the microwave spectrum is increasingly applied in clean energy technologies. This review discusses recent innovations using microwave fields in hydrogen production and synthesis of new battery materials highlighting the unique properties of microwave heating. Key innovations include microwave-assisted hydrogen generation from water hydrocarbons and ammonia and the synthesis of high-performance anode and cathode materials. Microwave-assisted catalytic water splitting using Gd-doped ceria achieves efficient hydrogen production below 250°C. For hydrocarbons advanced microwave-active catalysts Fe–Ni alloys and ruthenium nanoparticles enable high conversion rates and hydrogen yields. In ammonia synthesis microwaves reduce the energy demands of the Haber–Bosch process and enhance hydrogen production efficiency using catalysts such as ruthenium and Co2Mo3N. In battery technology microwave-assisted synthesis of cathode materials like LiFePO4 and LiNi0.5Mn1.5O4 yields high-purity materials with superior electrochemical performance. Developing nanostructured and composite materials including graphene-based anodes significantly improves battery capacities and cycling stability. The ability of microwave technology to provide rapid selective heating and enhance reaction rates offers significant advancements in clean energy technologies. Ongoing research continues to bridge theoretical understanding and practical applications driving further innovations in this field. This review aims to highlight recent advances in clean energy technologies based upon the novel use of microwave energy. The potential impact of these emerging applications is now being fully understood in areas that are critical to achieving net zero and can contribute to the decarbonization of key sectors. Notable in this landscape are the sectors of hydrogen fuel and battery technologies. This review examines the role of microwaves in these areas.

Heavy-duty fuel cell trucks are a promising approach to reduce the CO2 emissions of logistic fleets. Due to their higher powertrain energy density in comparison to battery-electric trucks they are especially suited for long-haul applications while transporting high payloads. Despite these great advantages the fleet integration of such vehicles is made difficult due to high costs and limited performance in thermally critical environmental conditions. These challenges are addressed in the European Union (EU) funded project ESCALATE which aims to demonstrate high-efficiency zero-emission heavy-duty vehicle (zHDV) powertrains that provide a range of 800 km without refueling or recharging. Powertrain components and their corresponding thermal components account for a large part of the production costs. For vehicle users higher costs are only acceptable if a significantly higher benefit can be achieved. Therefore it is important to size these components for the actual vehicle mission to avoid oversizing. In this paper an optimization method which determines the optimum component sizes for a given mission scenario under consideration of multiple criteria (e.g. costs performance and range) is presented.

This research evaluates four hydrogen (H2) production technologies via water electrolysis (WE): alkaline water electrolysis (AWE) proton exchange membrane electrolysis (PEME) anion exchange membrane electrolysis (AEME) and solid oxide electrolysis (SOE). Two scoring and ranking methods the MACBETH method and the Pugh decision matrix are utilized for this evaluation. The scoring process employs nine decision criteria: capital expenditure (CAPEX) operating expenditure (OPEX) operating efficiency (SOE) startup time (SuT) environmental impact (EI) technology readiness level (TRL) maintenance requirements (MRs) supply chain challenges (SCCs) and levelized cost of H2 (LCOH). The MACBETH method involves pairwise technology comparisons for each decision criterion using seven qualitative judgment categories which are converted into quantitative scores via M-MACBETH software (Version 3.2.0). The Pugh decision matrix benchmarks WE technologies using a baseline technology—SMR with CCS—and a three-point scoring scale (0 for the baseline +1 for better −1 for worse). Results from both methods indicate AWE as the leading H2 production technology which is followed by AEME PEME and SOE. AWE excels due to its lowest CAPEX and OPEX highest TRL and optimal operational efficiency (at ≈7 bars of pressure) which minimizes LCOH. AEME demonstrates balanced performance across the criteria. While PEME shows advantages in some areas it requires improvements in others. SOE has the most areas needing enhancement. These insights can direct future R&D efforts toward the most promising H2 production technologies to achieve the net-zero goal.

One of the key elements in the advancement of hydrogen (H2) and fuel cell technologies is to store H2 effectively for use in various industries such as transportation defense portable electronics and energy. Because of its highest energy density availability and environmental and health benefits H2 stands as a promising future energy carrier. Currently enterprises are searching for a solution for energy distribution management and H2 gas storage. Thus there is a need to develop an innovative solution to H2 storage that might be considered for later use in aviation applications. This study aims to synthesize an electrospun nanocomposite fiber (NCF) for an H2 storage application and to understand the absorption kinetics of the resultant highly porous NCF mats. This study incorporates functional NCFs with H2-sensitive inclusions to increase the storage capacity and absorption/desorption kinetics of H2 gas at lower temperatures and pressures. Here the electrospinning technique is utilized to produce NCFs with various nanoscale metal hydrides (MHs) and conductive particles which support enhancing H2 storage capacity and kinetics. These NCFs enable controlled H2 storage and improve thermal properties. Selected polymeric materials for H2 storage that have been investigated are polyacrylonitrile (PAN) polymethyl methacrylate (PMMA) and sulfonated polyether ether ketone (SPEEK) in combination with MHs and multiwalled carbon nanotubes (MWCNTs). On testing it was observed that H2 capacity with SPEEK which includes 4 wt% MWCNTs and 4 wt% MH MmNi4.5Fe0.5 shows significant H2 uptake compared to a PAN/PMMA polymer.

Achieving climate neutrality goals is inseparable from the sustainable development of modern cities. Municipal wastewater treatment plants (WWTP) are among the starting points when moving cities to Net-zero Greenhouse Gas (GHG) emissions and climate neutrality. This study focuses on the analysis of the integration of green hydrogen (H2) and biomethane technologies in WWTPs and on the impact of this integration on WWTPs’ energy neutrality. This study treats WWTP as an integrated energy system with certain inputs and outputs. Currently such systems in most cases have a significantly negative energy balance and in addition fossil fuel energy sources are used. Key findings highlight that the integration of green hydrogen production in WWTPs and the efficient utilization of electrolysis by-products can make such energy systems neutral or even positive. This study provides an analysis of the main technical presumptions for the successful integration of green hydrogen and biomethane production processes in WWTP. Furthermore a case study of a real wastewater treatment plant is presented.