Production & Supply Chain

High‐entropy amorphous catalysts (HEACs) integrate multielement synergy with structural disorder making them promising candidates for water splitting. Their distinctive features—including flexible coordination environments tunable electronic structures abundant unsaturated active sites and dynamic structural reassembly—collectively enhance electrochemical activity and durability under operating conditions. This review summarizes recent advances in HEACs for hydrogen evolution oxygen evolution and overall water splitting highlighting their disorder-driven advantages over crystalline counterparts. Catalytic performance benchmarks are presented and mechanistic insights are discussed focusing on how multimetallic synergy amorphization effect and in‐situ reconstruction cooperatively regulate reaction pathways. These insights provide guidance for the rational design of next‐generation amorphous high‐entropy electrocatalysts with improved efficiency and durability.

This study presents an innovative approach to the production of hydrogen from liquids following hydrothermal treatment of biowaste offering a potential solution for renewable energy generation and waste management. By combining biological and hydrothermal processes the efficiency of H2 production can be significantly improved contributing to a reduced carbon footprint and lower reliance on fossil fuels. The inoculum used was fermented sludge from a wastewater treatment plant which had been thermally pretreated to enhance microbial activity towards hydrogen production. Kitchen waste consisting mainly of plant-derived materials (vegetable matter) was used as a substrate. The process was conducted in batch 1-L bioreactors. The results showed that higher pretreatment temperatures (up to 180 ◦C) increased the hydrolysis of compounds and enhanced H2 production. However temperatures above 180 ◦C resulted in the formation of toxic compounds such as catechol and hydroquinone which inhibited H2 production. The highest hydrogen production was achieved at 180 ◦C (approximately 66 mL H2/gTVSKW). The standard Gompertz model was applied to describe the process kinetics and demonstrated an excellent fit with the experimental data (R2 = 0.99) confirming the model’s suitability for optimizing H2 production. This work highlights the potential of combining hydrothermal and biological processes to contribute to the development of sustainable energy systems within the circular economy.

This study investigates the cost-optimal capacity and operation of water electrolyzers in global net-zero CO2 energy systems. The production costs of hydrogen are largely determined by the electrolyzer capacity factor (i.e. full-load hours); therefore a global energy system model with an hourly temporal resolution was employed to consider the intermittency of variable renewable energy (VRE) and the dynamics of power system operations. Proton exchange membrane electrolysis is assumed in this study. The optimization results suggest three main findings. First water electrolysis is estimated to be a cost-effective option for achieving net-zero CO2 emissions. Under default technology assumptions the global installed capacity is projected to reach 2719 GW by 2050 with the majority of hydrogen consumed in the industry sector. Scaling up the supply chain is essential to realize this pathway. Second hydrogen and hydrogen-based fuels are economically competitive with negative emission technologies (NETs). A modest deployment of CO2 storage and NETs provides favorable conditions for water electrolysis deployment—and vice versa. Third flexible operation is critical to the widespread deployment of water electrolysis. In the default case the global weighted average capacity factor of electrolyzers is estimated at 37 % in 2050 to follow VRE output fluctuations. The results also indicate that limited operational flexibility may significantly hinder the cost-competitiveness of electrolyzer deployment.

Proton transport plays a crucial role in acidic oxygen evolution reaction process. Iridium oxide (IrOx) exhibits good stability yet its catalytic activity remains insufficient at high current density. Trace sulfonates introduced into electrocatalysts can enhance the proton transfer process; however their significant leaching compromises catalyst stability. Herein we report a sulfonic groups ( − SO3H) grafted catalyst Ir/IrOx ~ SO3H featuring covalent bonding between sulfonic groups and iridium oxide. The anchored sulfonic groups facilitate enhancing the proton transfer process and promote the formation of *OOH intermediates thereby accelerating the oxygen evolution reaction kinetics. A proton exchange membrane water electrolysis assembled with an Ir/IrOx ~ SO3H anode needs a cell voltage of only 1.75 V at 3.0 A cm−2 and stably operates over 1000 h without leaching of sulfonic groups outperforming a water electrolysis assembled with a commercial iridium oxide anode in activity. Moreover the elevated surface potential of catalyst particles alleviates their agglomeration which is benefit to the industrial membrane electrode preparation. The strong bonding strategy holds promise for advancing the development of sulfonates-grafted catalysts in energy conversion applications.

Hydrogen has the potential to become a key component of the global economy by reducing reliance on fossil fuel imports enhancing energy independence and mitigating climate change. Its future role depends on factors such as availability cost competitiveness supportive legislation public–private collaboration and advancements in catalyst development for electrolyzers and fuel cells. In this study carbon-supported multimetallic MoFeNiP catalysts were developed as cost-effective platinum-free electrocatalysts for the hydrogen evolution reaction (HER) via polymer–metal gel precursors and subsequent pyrolysis at different temperatures. The catalysts were evaluated in both acidic (0.5 M H2SO4) and alkaline (1 M KOH) media revealing that C-MoFeNiP-1200 performed best in alkaline conditions while C-MoFeNiP-1000 showed superior activity in acidic media. Electrochemical analyses confirmed favorable kinetics efficient charge transfer and good long-term stability. These results demonstrate that tuning pyrolysis temperature allows precise control over catalyst structure surface properties and performance offering a sustainable and practical approach for designing efficient HER electrocatalysis.