Production & Supply Chain

Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology for green hydrogen production. However the adoption of PEMWE-based hydrogen production systems remains limited due to several challenges including high material costs limited performance and durability and difficulties in scaling the technology. Computational modeling serves as a powerful tool to address these challenges by optimizing system design improving material performance and reducing overall costs thereby accelerating the commercial rollout of PEMWE technology. Despite this conventional models often oversimplify key components such as porous transport and catalyst layers by assuming constant porosity and neglecting the spatial heterogeneity found in real electrodes. This simplification can significantly impact the accuracy of performance predictions and the overall efficiency of electrolyzers. This study develops a mathematical framework for modeling variable porosity distributions—including constant linearly graded and stepwise profiles—and derives analytical expressions for permeability effective diffusivity and electrical conductivity. These functions are integrated into a three-dimensional multi-domain COMSOL simulation to assess their impact on electrochemical performance and transport behavior. The results reveal that although porosity variations have minimal effect on polarization at low voltages they significantly influence internal pressure species distribution and gas evacuation at higher loads. A notable finding is that reversing stepwise porosity—placing high porosity near the membrane rather than the channel—can alleviate oxygen accumulation and improve current density. A multi-factor comparison highlights this reversed configuration as the most favorable among the tested strategies. The proposed modeling approach effectively connects porous media theory and systemlevel electrochemical analysis offering a flexible platform for the future design of porous electrodes in PEMWE and other energy conversion systems.

Electrolytic hydrogen can support the decarbonization of the power sector. Achieving cost-effective power-to-gas-to-power (PGP) integration through targeted emissions pricing can accelerate the adoption of electrolytic hydrogen in greenhouse gas-intensive power sectors. This study develops a framework for assessing the economic viability of electrolytic hydrogen-based PGP systems in fossil fuel-dependent grids while considering the competing objectives of the electricity system operator a risk-averse investor and the government. Here we show that given the risk-averse investor’s inherent pursuit of profit maximization a break-even carbon abatement cost of at least 57 Canadian Dollars per tonne of CO₂ by 2030 from the government with a shift in electricity market dispatch rules from sole system marginal pricereduction to system-wide emissions reduction is essential to stimulate price discovery for low-cost hydrogen production and contingency reserve provision by the PGP system. This work can help policymakers capture and incentivize the role of electrolytic hydrogen in low-carbon power sector planning.

Water management is crucial for the performance of anion exchange membrane water electrolyzers (AEM-WEs) to maintain membrane hydration and enable phase separation between hydrogen gas and liquid water. Therefore careful material selection for the anode and cathode is essential to enhance reactant/product transport and optimize water management under ‘dry cathode’ conditions. This study investigates the wetting characteristics of two commercially available porous transport layers (PTLs) used in AEM-WE: carbon paper and carbon paper with a microporous layer (MPL). Wettability was measured under static quasi-static and dynamic conditions to assess the effect of water and electrolytes (NaOH KOH K2CO3) across concentrations (up to 1 M) and operational temperatures (20 °C to 92 °C). Carbon paper exhibits mild hydrophobicity (advancing contact angles of ∼120° however with receding contact angle ∼0°) whereas carbon paper with MPL demonstrates superhydrophobicity (advancing and receding contact angles >145° and low contact angle hysteresis) maintaining a stable Cassie-Baxter wetting state. Dynamic wetting experiments confirmed the robustness of the superhydrophobicity in carbon paper with MPL facilitating phase separation between hydrogen gas and liquid water. The presence of supporting electrolytes did not significantly affect wettability and the materials retained hydrophobic properties across different temperatures. These findings highlight the importance of MPLs in optimizing water transport and gas rejection within AEM-WEs ensuring efficient and stable operation under “dry cathode” conditions. These PTLs (with and without the addition of the MPL) were integrated into AEM-WE and polarization curves were run. Preliminary data in a specific condition suggested the presence of the MPL within the PTL enhance AEM-WE performance.

The potential for hydrogen production from heavy oil reservoirs has gained significant attention as a dual-benefit process for both enhanced oil recovery and low-carbon energy generation. This study investigates the technical and economic feasibility of producing hydrogen from heavy oil reservoirs using two primary in situ combustion gasification strategies: cyclic steam/air and CO2 + O2 injection. Through a comprehensive analysis of technical barriers economic drivers and market conditions we assess the hydrogen production potential of each method. While both strategies show promise they face considerable challenges: the high energy demands associated with steam generation in the steam/air strategy and the complexities of CO2 procurement capture and storage in the CO2 + O2 method. The novelty of this work lies in combining CMG-STARS reservoir simulations with GoldSim techno-economic modeling to quantify hydrogen yields production costs and oil–hydrogen revenue trade-offs under realistic field conditions. The analysis reveals that under current technological and market conditions the cost of hydrogen production significantly exceeds the market price rendering the process economically uncompetitive. Furthermore the dominance of oil production as the primary revenue source in both methods limits the economic viability of hydrogen production. Unless substantial advancements are made in technology or a more cost-efficient production strategy is developed hydrogen production from heavy oil reservoirs is unlikely to become commercially viable in the near term. This study provides crucial insights into the challenges that must be addressed for hydrogen production from heavy oil reservoirs to be considered a competitive energy source.

This study conducts a Life Cycle Sustainability Assessment (LCSA) of hydrogen production pathways in Alberta Canada evaluating environmental economic and social dimensions. Eight pathways are analyzed: steam methane reforming (SMR) with and without carbon capture and storage (CCS) autothermal reforming (ATR) with and without CCS and with and without grid electricity as well as alkaline electrolysis using grid and wind electricity. While alkaline electrolysis with wind electricity shows the best performance under the climate change and ozone depletion categories ATR + CCS (CO2 capture rate of 91 % no-grid electricity) demonstrates the strongest performance in seven of nine environmental impact categories being the worst performer in none and having the lowest social risks. Economically SMR and ATR without CCS exhibit the lowest levelized cost of hydrogen followed by ATR + CCS (CO2 capture rate of 91 % no-grid electricity). ATR + CCS (CO2 capture rate of 91 % no-grid electricity) emerges as a promising pathway offering an overall balance of sustainability under the current study’s assumptions. The results suggest that a blue hydrogen to electricity scenario where ATR + CCS with 100 % on-site hydrogen-fueled power generation replaces grid electricity may be the most suitable pathway for hydrogen production in Alberta. Key recommendations include optimizing environmental performance in climate change and ozone depletion impacts reducing costs and mitigating social risks in ATR pathways. This LCSA supports policies and investments to advance hydrogen’s role in Alberta’s decarbonization and energy transition.

This review critically examines recent advancements in MXene-based nanocomposites and their roles in photocatalytic applications for environmental remediation and renewable energy. MXenes two-dimensional transition metal carbides nitrides and carbonitrides (Mn+1XnTx where M = transition metal X = C/N Tx = surface terminations such as –O –OH –F) exhibit high electrical conductivity tunable band structures hydrophilic surfaces and large specific surface areas. These properties make them highly effective in enhancing photocatalytic activity when incorporated into composite systems. The review summarizes synthesis methods structural modifications and the mechanisms underlying photocatalytic performance highlighting their efficiency in degrading organic inorganic and microbial pollutants converting CO₂ into value-added chemicals and generating H₂ via water splitting. Key challenges including stability oxidation and scalability are analyzed along with strategies such as surface passivation heterojunction formation and hybridization with antioxidant materials to improve performance. Future research should focus on developing green synthesis methods improving long-term stability and exploring scalable production to facilitate practical deployment. These insights provide a comprehensive understanding of MXene nanocomposites supporting their advancement as multifunctional photocatalysts for a clean and sustainable energy future.

Coal constitutes China’s most significant resource endowment at present. Utilizing coal resources for hydrogen production represents an early-stage pathway for China’s hydrogen production industry. The analysis of energy quality and carbon emissions in coal gasification-based hydrogen production holds practical significance. This paper integrates the exergy analysis methodology into the traditional LCA framework to evaluate the exergy and carbon emission scales of coal gasification-based hydrogen production in China considering the technical conditions of CCUS. This paper found that the life cycle exergic efficiency of the whole chain of gasification-based hydrogen production in China is accounted to be 38.8%. By analyzing the causes of exergic loss and energy varieties it was found that the temperature difference between the reaction of coal gasification and CO conversion unit and the pressure difference due to the compressor driven by the electricity consumption of the compression process in the variable pressure adsorption unit are the main causes of exergic loss. Corresponding countermeasures were suggested. Regarding decarbonization strategies the CCUS process can reduce CO2 emissions across the life cycle of coal gasification-based hydrogen production by 48%. This study provides an academic basis for medium-to-long-term forecasting and roadmap design of China’s hydrogen production structure.

The United Nations has set a global vision towards emissions reduction and green growth through the Sustainable Development Goals (SDGs). Towards the realisation of SDGS 7 9 and 13 we focus on green hydrogen production as a potential pathway to achievement. Green hydrogen produced via water electrolysis powered by renewable energy sources represents a pivotal solution towards climate change mitigation. Energy access in West Africa remains a challenge and dependency on fossil fuels persists. So green hydrogen offers an opportunity to harness abundant solar resources reduce carbon emissions and foster economic development. This study evaluates the techno-economic feasibility of green hydrogen production in five West African countries: Ghana Nigeria Mali Niger and Senegal. The analyses cover the solar energy potential hydrogen production capacities and economic viability using the Levelised Cost of Hydrogen (LCOH) and Net Present Value (NPV). Results indicate substantial annual hydrogen production potential with LCOH values competitive with global benchmarks amidst the EU’s Carbon Border Adjustment Mechanism (CBAM). Despite this potential several barriers exist including high initial capital costs policy and regulatory gaps limited technical capacity and water resource constraints. We recommend targeted strategies for strengthening policy frameworks fostering international partnerships enhancing regional infrastructure integration and investing in capacity-building initiatives. By addressing these barriers West Africa can be a key player in the global green hydrogen market.

The growing demand for green hydrogen is driving the expansion of water electrolysis. The resulting oxygen byproduct offers potential added value when used in sectors with high oxygen demand such as wastewater treatment. This study investigates the techno-economic viability of using electrolysis oxygen to supplement conventional air blowers in the aeration process of municipal wastewater treatment plants (WWTPs) to reduce aeration costs and thereby improve the overall economics of hydrogen production. A comprehensive system model is developed incorporating renewable electricity supply water electrolysis hydrogen compression storage and transport as well as WWTP aeration via conventional air blowers and electrolysis oxygen. Results show that electrolysis oxygen can reduce WWTP aeration costs by up to 68%. If these cost reductions are attributed as a benefit to the hydrogen system they correspond to hydrogen supply cost savings of up to 0.39 EUR/kgH2. However the analysis indicates that economic viability is substantially influenced by factors such as the distance of hydrogen transport from the WWTP to the European Hydrogen Backbone feed-in point which should not exceed 25 km and the alignment between the scale of hydrogen production and the size of the WWTP with cost-effective integration being particularly feasible for larger WWTPs (≥500000 PE).

Climate-change mitigation in North America demands rapid deep cuts in carbon-dioxide emissions from hard-toabate industrial power-generation and transport sectors. Carbon capture and storage (CCS) is one of the few technological routes that can decouple continued use of fossil-derived energy and materials from their climate externalities. Yet deployment across the US and Canada still trails the scale implied by regional net-zero pledges. This review addresses that gap by synthesizing technical economic policy and social dimensions of CCS and complements global syntheses with a granular assessment of North America’s unique emission profile infrastructure advantages and regulatory frameworks. Methodologically the review disaggregates the CCS chain into six pillars: (i) current emission baselines; (ii) capture systems icluding post- pre- and oxy-combustion chemical-looping combustion (CLC) and direct air capture (DAC); (iii) capture technologies (e.g. absorption adsorption membrane cryogenic and hybrid processes); (iv) storage pathways (geological oceanic and emerging biological or mineral options); (v) cross-cutting economic policy and social factors; and (vi) deployment status plus future outlook. Post-combustion capture remains the most retrofit-ready option for the region’s ageing coal and gas fleet yet solvent regeneration still imposes energy penalties of 8–10 percentagepoints. Pre-combustion and oxy-fuel routes offer thermodynamic advantages for new-build plants but require high-capex gasifiers or cryogenic air separation units slowing adoption. Emerging CLC and DAC concepts could unlock low-carbon fuels and negative emissions respectively but remain costly and pre-commercial. No single technology meets all performance criteria making hybrid configurations—such as membrane–cryogenic or membrane–amine schemes—particularly promising. North America’s subsurface offers multi-teratonne theoretical storage capacity in saline formations depleted hydrocarbon reservoirs and CO2-EOR sites suggesting physical room is not the bottleneck. Instead economics dominate: levelized capture costs today range from around $15/tCO2 in natural-gas processing to over $120/t in power and cement and long-distance pipeline networks are sparse outside existing enhanced oil recovery (EOR) corridors. Recent federal incentives can shift project economics decisively yet policy volatility and permitting hurdles still threaten investment certainty. Societal acceptance emerges as another critical lever. Surveys reveal generally favorable attitudes toward CCS in principle but heightened opposition to local storage projects. Transparent monitoring–verification frameworks benefit-sharing mechanisms and durable bipartisan policies are therefore essential to secure a “social licence” for large-scale CO2 injection. This review concludes that widescale CCS in North America is technically feasible and increasingly cost-competitive when paired with robust incentives abundant storage capacity and existing pipeline know-how. Realizing its full mitigation potential will hinge on coordinated build-out of transport networks harmonized federal–provincial regulations continued R&D into low-energy capture materials and integrated assessments that weigh CCS alongside renewables efficiency and negative-emission strategies. The roadmap presented herein provides stakeholders with actionable insights to accelerate that transition positioning North America as both a proving ground and a global exemplar for scalable responsibly governed CCS.

The management of sewage sludge presents a pressing environmental and economic challenge due to its increasing global production and complex hazardous composition. Gasification offers a viable method for converting this waste into valuable energy resources. This study investigates whether integrating experimental and computational techniques can enhance the understanding and optimization of sludge gasification. Two types of sewage sludge SSG from Rethymno and SSD from Dubai were evaluated using an entrained flow gasifier under controlled thermal and flow conditions. The methodology combines equilibrium modeling computational fluid dynamics (CFD) drop tube reactor (DTR) experiments and artificial neural network (ANN) modeling. The ANN was combined with Kissinger analysis to obtain kinetics from the ANN outputs and derive thermodynamic parameters used to enhance CFD fidelity. Gas composition analysis and scanning electron microscopy (SEM) revealed that SSD decomposes more easily with a lower activation energy (42.29–138.31 kJ/mol) and a lower Gibbs free energy. In contrast SSG demonstrated greater thermal stability and reactivity. SSG achieved consistently higher cold gas efficiency (CGE) reaching 53.66 % in equilibrium modeling 45.50 % in CFD and 38.90 % in experiments compared to SSD’s 48.86 % 37.81 % and 31.19 % respectively. SEM imaging confirmed an increase in porosity and surface area for SSG after gasification. These results indicate that the type of sludge has a significant impact on energy recovery and that ANN-calibrated thermokinetics and CFD enhance process predictability. This integrated method scales hydrogen generation and promotes sustainable waste-toenergy technology.

The accelerating global demand for hydrogen is pushing for renewable and waste derived hydrogen production processes where date palm waste (DPW) has been identified as an available and unexploited agricultural residue that has the potential to be a sustainable source of hydrogen. The current work focuses on developing and evaluating four different process configurations in terms of energy environment and economics for producing hydrogen from DPW using Aspen Plus® simulation tool. Case 1 represents the standalone DPW gasification with CO₂ capture via methanol absorption Case 2 represents the DPW gasification with CaO-based chemical looping for CO₂ capture Case 3 represents the DPW gasification integrated with steam methane reforming (SMR) and methanol-based CO₂ capture and Case 4 represents the DPW gasification integrated with SMR and CaO-based CO₂ capture. Each case was evaluated in terms of syngas composition hydrogen production lower heating value CO₂ captured utility demand process efficiency and H2 production cost. Hydrogen production ranged from 974.55 t/year (Case 1) and 988.83 t/year (Case 2) to 2032.32 t/year (Case 3) and 2048.61 t/year (Case 4). CO₂ capture was also more effective in Case 4 (16929.49 t/year) compared to Case 1 (7676.30 t/year). Process efficiency improved from 33 % in Case 1 to 47 % in Case 2 and from 32 % in Case 3 to further to 55 % in Case 4. Economically Case 1 offered the highest hydrogen production cost ($5.03/kg) followed by Case 2 ($4.77/kg) while Case 3 and Case 4 achieved significantly lower production costs of $2.89/kg and $2.69/kg respectively.

Microalgae-based biohydrogen (MaBHP) can couple CO2 mitigation with renewable fuel generation and wastewater remediation yet deployment is limited by low light-to-H2 efficiencies and high cultivation and processing costs. This review maps scale-up barriers across cultivation H2 induction and purification and prioritizes strategies with demonstrated cost or yield impact toward industrial feasibility. The review synthesized quantitative evidence (2000–2025) from techno-economic and life-cycle studies and pilot demonstrations covering wastewater integration flue-gas CO2 utilization immobilized cultivation hybrid ORP–PBR operation and biorefinery co-products. Results showed that cultivation dominates the process cost: typical biomass costs are $3.54–$5.78/kg in tubular PBRs versus $3.42–$4.13/kg in ORPs; an automation/modularization case decreased microalgae production cost from $89 to $16/kg at ~200 t/yr. Today MaBHP via biophotolysis remains $7.2–$7.6/kg—above green electrolysis ($5–$7/kg) and grey/blue SMR ($1–$3/$1.6–$3.5/kg). Integration levers show tangible gains: secondary-treated wastewater enabled Chlorella growth with 76 % NH4 + removal and 53 % lipid accumulation; the spent medium yielded 200.8 μmolH2/mgchlorophyll.a in cyanobacteria; swinewastewater loops cut freshwater use six-fold with 45.5 mLH2/gVS; alginate immobilization raised H2 ~40 % (to 2.4 LH2/Lculture) over five reuse cycles. A CSTR nutrient-recovery line on digested Scenedesmus recovered 68 % N and 72 % P via struvite reducing synthetic fertilizer ~35 %; flue-gas CO2 (12 % v/v) lifted biomass 22 % and reduced carbon-supplement cost 86 %. The results show that combining wastewater/nutrient circularity CO2 coutilization oxygen/electron-flow control high-A/V reactors with automation and co-product valorization can narrow the cost gap and orient MaBHP toward future $1–$2/kg benchmarks.

For five decades photocatalysis has promised clean hydrogen from solar energy yet a persistent “efficiency ceiling” linked to fundamental challenges including the trade-off between light absorption and redox potential in single-component materials has hindered its practical application. This review illuminates three key paradigm shifts overcoming this challenge. First we examine Z-scheme and S-scheme heterojunctions which resolve the bandgap dilemma by spatially separating redox sites to achieve both broad light absorption and strong redox power. Second we discuss replacing the sluggish oxygen evolution reaction (OER) with value-added organic oxidations. This strategy bypasses kinetic bottlenecks and improves economic viability by co-producing valuable chemicals from feedstocks like biomass and plastic waste. Third we explore manipulating the reaction environment where synergistic photothermal effects and concentrated sunlight can dramatically enhance kinetics and unlock markedly enhanced solar-to-hydrogen (STH) efficiencies. Collectively these strategies chart a clear course to overcome historical limitations and realize photocatalysis as an impactful technology for a sustainable energy future.

Titanium dioxide (TiO2) is widely used in solar cells and photocatalysts given its excellent photoactivity low cost and high structural electronic and optical stability. Here a novel TiO2 composite was prepared by coating TiO2 inverse opal (IO) with TiO2 nanorods (NRs). With a porous three-dimensional network structure the composite exhibited higher light absorption; enhanced the separation of the electron–hole pairs; deepened the infiltration of the electrolyte; better transported and collected charge carriers; and greatly improved the power conversion efficiency (PCE) of the quantum-dot sensitized solar cells (QDSSCs) based on it while also boosting its own photocatalytic hydrogen generation efficiency. A very high PCE of 12.24% was achieved by QDSSCs utilizing CdS/CdSe sensitizer. Furthermore the TiO2 composite exhibited high photocatalytic activity with a H2 release rate of 1080.2 µ mol h−1 g −1 several times that of bare TiO2 IO or TiO2 NRs.

The development of durable and efficient catalysts capable of driving both hydrogen and oxygen evolution reactions is essential for advancing sustainable hydrogen production through overall water electrolysis. In this study we developed a corrosion-mediated approach where Ni ions originate from the self-corrosion of the nickel foam (NF) substrate to construct Pt-modified NiFe layered double hydroxide (Pt-NiFeOxHy@NiFe-LDH) under ambient conditions. The obtained catalyst exhibits a hierarchical architecture with abundant defect sites which favor the uniform distribution of Pt clusters and optimized electronic configuration. The Pt-NiFeOxHy@NiFe-LDH catalyst constructed through the interaction between Pt sites and defective NiFe layered double hydroxide (NiFe-LDH) demonstrates remarkable hydrogen evolution reaction (HER) activity delivering an overpotential as low as 29 mV at a current density of 10 mA·cm−2 and exhibiting a small tafel slope of 34.23 mV·dec−1 in 1 M KOH together with excellent oxygen evolution reaction (OER) performance requiring only 252 mV to reach 100 mA·cm−2 . Moreover the catalyst demonstrates outstanding activity and durability in alkaline seawater maintaining stable operation over long-term tests. The Pt-NiFeOxHy@NiFe-LDH electrode when integrated into a two-electrode system demonstrates operating voltages as low as 1.42 and 1.51 V for current densities of 10 and 100 mA·cm−2 respectively and retains outstanding stability under concentrated alkaline conditions (6 M KOH 70 ◦C). Overall this work establishes a scalable and economically viable pathway toward high-efficiency bifunctional electrocatalysts and deepens the understanding of Pt-LDH interfacial synergy in promoting water-splitting catalysis.

This article describes hydrogen production via water splitting because of high green energy demand globally. The amounts of hydrogen produced with zirconium in thermal processes at 473 K and radiation-thermal processes at 473 K and 773K were 1.55 x 1018 2.2 x 1018 and 4.1 x 1018 molecules/g. These amounts on aluminum and stainless steel were 1.05 x 1018 1.95 x 1018 and 3.0 x 1018 molecules/g; and 0.30 x 1018 1.27 x 1018 and 2.6 x 1018 molecules/g. A comparison was carried out and the order of hydrogen production was zirconium > aluminum > stainless steel. The activation energy in radiation-thermal and thermal processes were 14.2 and 65.0 kJ/mol (Zr) 12.05 and 63.1 kJ/mol (Al) and 11.16 and 61.52 kJ/mol (SS). The mechanisms of water splitting were developed and described for future use. The described methods are scalable and can be transferred to a pilot scale.

An industrially relevant method for obtaining hydrogen from hydrocarbons without emitting carbon into the atmosphere involves ethanol-steam reforming followed by carbon capture. Herein we present a detailed conceptual process using ethanol-stream reforming to produce blue hydrogen integrated with a carbon capture plant followed by a techno-economic analysis. In the first step the Aspen plus-based simulation of ethanolstream reforming reactions is performed to optimize the reforming reactor geometrical parameters for a 10 t/ day of hydrogen production. Afterward the carbon capture system was designed with a standalone absorber and stripper which were subsequently integrated for solvent makeup calculation. Considering the target value of hydrogen production the optimized reactor diameter and length were found to be 0.18 and 2 m respectively corresponding to reactant flow (200 t/day) and heat duty (3.14 MW) at optimal circumstances. Absorber and stripper packing heights of 12.2 m and 5 m respectively with column diameters of 1.22 m and 2.60 m are required to extract 95 % CO2 from the reformed product stream. The techno-economic analysis indicates that the cost of producing one kilogram of H2 is $3.5. The computed internal rate of return is 16.6 % the discounted payback period is 6 years and the net present value is $13 million.

The increasing integration of renewable energy sources (RES) in Spain is leading to substantial amounts of surplus electricity presenting a strategic opportunity for green hydrogen production as a key enabler of energy storage and decarbonisation. This study quantifies this untapped potential for 2024. Based on the difference between installed renewable capacity and actual generation an economically viable surplus of 18419 GWh was identified within an optimal 10-h operating window. The hydrogen production potential was modelled for three electrolysis technologies—Alkaline (AEL) Proton Exchange Membrane (PEM) and Anion Exchange Membrane (AEM)—using total energy consumption values of 57.40 65.55 and 59.95 MWh/t H2 respectively including auxiliary systems. The estimated annual hydrogen production ranges from 280999 t (PEM) to 320897 t (AEL) with AEM yielding an intermediate value of 307247 t. The analysis reveals a strong regional concentration with more than 63% of the potential located in Castile and León Andalusia Castile-La Mancha and Extremadura. While this range represents an upper technical limit it highlights the significant opportunity to valorise surplus renewable energy contingent on targeted investment and a supportive regulatory framework.

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.

This study presents a comprehensive framework that integrates high-resolution energy forecasting and technoeconomic modeling to assess green hydrogen production potential in Flanders Belgium. Using 15-min interval data from the Elia Group four deep learning models (LSTM BiLSTM GRU and CNN-LSTM) were developed to forecast regional photovoltaic (PV) and onshore wind energy generation. These forecasts informed the estimation of hydrogen yields and the evaluation of the levelized cost of hydrogen (LCOH) under different configurations. Results show that wind-powered hydrogen production achieves the lowest LCOH (6.63 €/kg) due to higher annual operating hours. Among electrolysis technologies alkaline electrolysis (AEL) offers the lowest cost while proton exchange membrane (PEMEL) provides greater flexibility for intermittent power sources. The hybrid PVwind system demonstrated seasonal complementarity increasing annual hydrogen yield and improving production stability. The proposed framework supports regional planning and highlights strategic investment opportunities for cost-effective green hydrogen deployment.

A potential strategy to promote the use of clean energy is the development of catalyst-coated cathodic electrodes that are economical effective and sustainable to enhance the generation of hydrogen (H2) through the electrolysis process. This study investigates the unique design and use of stainless steel (SS) coated with a CuNiZnFeOx catalyst as both anode and cathode electrodes in the alkaline electrolysis process. The electrode exhibits an improved electrochemical behavior achieving a current density of 92 mA/cm2 at an applied voltage of 2.5 V with a surface area of 36 cm2 in 1 M KOH electrolyte at 25 ◦C. Furthermore the H2 production is systematically investigated by varying electrolyte concentration applied voltage and temperature. The results demonstrate that H2 production increases significantly with enhanced electrolyte concentration (3102 mL at 2 M KOH) applied voltage (3468 mL at 3.0 V) and temperature (3202 mL at 60 ◦C) over a 300 min electrolysis time. However optimal operating conditions are determined to be 1 M KOH 2.5 V and 25 ◦C balancing performance and energy efficiency. The improved performance is primarily attributed to enhanced ionic conductivity reduced internal resistance and the synergistic catalytic activity of the Cu-integrated NiZnFeOx coating.

The increasing global demand for clean energy highlights hydrogen as a strategic energy carrier due to its high energy density and carbon-free utilization. Currently steam methane reforming (SMR) is the most widely applied method for hydrogen production; however its high CO2 emissions undermine the environmental benefits of hydrogen. Blue hydrogen production integrates carbon capture and storage (CCS) technologies to overcome this drawback in the SMR process significantly reducing greenhouse gas emissions. This study integrated a MATLAB-R2025b-based plug flow reactor (PFR) model for SMR kinetics with an Aspen HYSYS-based CCS system. The effects of reformer temperature (600–1000 ◦C) and steam-to-carbon (S/C) ratio (1–5) on hydrogen yield and CO2 emission intensity were investigated. Results show that hydrogen production increases with temperature reaching maximum conversion at 850–1000 ◦C while the optimum performance is achieved at S/C ratios of 2.5–3.0 balancing high hydrogen yield and minimized methane slip. Conventional SMR generates 9–12 kgCO2/kgH2 emissions whereas SMR + CCS reduces this to 2–3 kgCO2/kgH2 achieving more than 75% reduction. The findings demonstrate that SMR + CCS integration effectively mitigates emissions and provides a sustainable bridging technology for blue hydrogen production supporting the transition toward lowcarbon energy systems.