Energy Reviews最新文献

{"title":"Synergistic defect ensembles in Cu catalysts for CO2 electroreduction: An integrated perspective on synthesis, characterization, and performance","authors":"Nan Wang,&nbsp;Riguo Mei,&nbsp;Yin Cui,&nbsp;Rongyue Wang,&nbsp;Zhongwei Chen,&nbsp;Tao Yang,&nbsp;Xidong Lin,&nbsp;Xuanxuan Bi,&nbsp;Qingxia Liu","doi":"10.1016/j.enrev.2026.100205","DOIUrl":"10.1016/j.enrev.2026.100205","url":null,"abstract":"<div><div>The excessive consumption of fossil fuels globally has led to a sharp increase in atmospheric carbon dioxide (CO₂) concentration (exceeding 420 ppm by 2023), resulting in urgent issues related to the greenhouse effect and ecological imbalance. Electrochemical CO₂ reduction (CO₂RR) technology offers a sustainable pathway toward carbon neutrality by converting CO₂ into value-added carbon-based fuels (<em>e.g.</em>, ethylene and ethanol) and chemical feedstocks. Copper (Cu)-based catalysts, distinguished by their unique capability to facilitate carbon monoxide intermediate (∗CO) coupling, remain the only metallic materials capable of efficient C₂₊ product synthesis. However, their intrinsic activity is constrained by limitations such as high overpotential, low selectivity, and insufficient stability. Defect engineering provides a powerful atomic-scale strategy to address these challenges. Unlike previous reviews that focus on isolated defect categories, this review presents a systematic analysis of the full defect spectrum including vacancies, doping, grain boundaries, and lattice strain, with emphasis on their synergistic interplay. We establish a unified framework demonstrating how diverse defect types converge on modulating the d-band center and ∗CO surface coverage, the two decisive descriptors for C₂₊ selectivity. By integrating <em>in situ</em> characterization techniques and theoretical computations, we elucidate the structure-activity relationships between defect sites and the adsorption energies of key intermediates (<em>e.g.</em>, ∗COOH and ∗CO), and analyze the influence of defect density/distribution on C-C coupling efficiency. Furthermore, we highlight applications of advanced characterization methods (<em>e.g.</em>, synchrotron radiation and spherical aberration-corrected transmission electron microscopy) in studying the dynamic evolution of defects. We elucidate structure-activity relationships between defect configurations and intermediate adsorption energetics, while bridging atomic-level design with industrial performance requirements.</div><div>We posit that the synergistic integration of multiple defect types represents the critical frontier for achieving industrial-level C₂₊ production from CO₂ electroreduction. This review provides a theoretical foundation and practical roadmap for rational design of next-generation CO₂RR catalysts.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 3","pages":"Article 100205"},"PeriodicalIF":16.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research progress of isothermal compressed air energy storage system and technology","authors":"Saisong Huang,&nbsp;Yuting Yang,&nbsp;Siqi Zhang,&nbsp;Yu Liu,&nbsp;Xinjing Zhang,&nbsp;Yujie Xu,&nbsp;Haisheng Chen","doi":"10.1016/j.enrev.2026.100203","DOIUrl":"10.1016/j.enrev.2026.100203","url":null,"abstract":"<div><div>Decarbonizing the electricity sector is crucial for achieving the carbon peaking and carbon neutrality goals. Renewable energy sources, such as wind and solar power, can progressively replace fossil fuels (coal, natural gas, etc). While, long-duration energy storage technologies are required to reconcile renewable energy output with electricity demand. Compressed air energy storage (CAES) is an effective solution for this mismatch, thereby enabling a high penetration of renewable energy. As a vital part of CAES, isothermal compressed air energy storage (ICAES) features a high round-trip efficiency (RTE), demonstrating tremendous application prospects in future power systems. This study reviews recent advances in ICAES technology, which primarily includes spray injection technology and liquid piston (LP) technology. The operating principles and system configurations of the ICAES technologies are briefly introduced. Furthermore, a comprehensive review is presented from the perspectives of theoretical research, experimental studies and demonstrations. These isothermal technologies are compared and discussed in terms of technology maturity, power capacity, and round-trip efficiency. Additionally, these studies on key components are reviewed, including isothermal compressors, expanders, and air storage devices. Finally, the research methods for heat transfer characteristics and the heat transfer enhancement mechanisms are discussed. This study provides a comprehensive reference for the optimization of ICAES systems and key components, and proposes suggestions for future research and development to promote commercial application.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 3","pages":"Article 100203"},"PeriodicalIF":16.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148855159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding fiber-matrix interphase formation through waterborne polyurethane sizing strategies, interfacial engineering, and performance frontiers in carbon fiber composites","authors":"Qiancheng Xiong,&nbsp;Zhengchao Huang,&nbsp;Qiuting Luo,&nbsp;Tian Yu,&nbsp;Yongcheng Li,&nbsp;Jie Zhang,&nbsp;Feiyan Xie,&nbsp;Xuefeng Zhang,&nbsp;Yong Yang,&nbsp;Jiao Zou,&nbsp;Jing Chai,&nbsp;Chuanyin Xiong,&nbsp;Guocong Liu","doi":"10.1016/j.enrev.2026.100206","DOIUrl":"10.1016/j.enrev.2026.100206","url":null,"abstract":"<div><div>Carbon fiber (CF) is renowned for its exceptional mechanical properties; however, its inherent surface inertness and susceptibility to processing damage frequently compromise interfacial adhesion with polymer matrices. Sizing treatment serves as an effective and industrially scalable strategy to overcome this limitation. This review systematically examines the protective and thermodynamic roles of sizing agents, the four fundamental interfacial mechanisms of chemical bonding, mechanical interlocking, physical adsorption, and interphase formation, alongside the specific characterization techniques employed to analyze them. Conventional sizing formulations, encompassing epoxy, acrylic, polyester, polyimide, polyether, and vinyl resin systems, are evaluated with a primary focus on matrix compatibility and inherent performance trade-offs. The discussion subsequently highlights waterborne polyurethane (WPU) as a highly sustainable and structurally versatile sizing platform. We critically assess recent advancements in WPU modification achieved through chemical grafting, supramolecular engineering, bio-based feedstocks, and metal oxide hybridization. While these targeted modifications significantly enhance fiber wettability and interfacial shear strength, they can concurrently introduce challenges related to brittleness, moisture sensitivity, or manufacturing complexity. Drawing from these comparative insights, we outline rational design principles for engineering robust composite interphases. Finally, we explore emerging research directions, emphasizing self-healing functionalities, adaptability to rapid manufacturing processes, and long-term reliability in energy-critical applications such as wind turbine blades and hydrogen storage vessels. Life cycle considerations, particularly the integration of bio-based components and the recyclability of composite are also addressed. Ultimately, this review aims to provide a clear roadmap for the development of next-generation CF sizing agents through advanced interfacial engineering.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 3","pages":"Article 100206"},"PeriodicalIF":16.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in MXene-Enabled triboelectric nanogenerators: From material chemistry to emerging applications","authors":"S M Sohel Rana","doi":"10.1016/j.enrev.2026.100204","DOIUrl":"10.1016/j.enrev.2026.100204","url":null,"abstract":"<div><div>Triboelectric nanogenerators (TENGs) have emerged as a promising technology for harvesting ubiquitous mechanical energy and enabling self-powered electronic systems. However, achieving high output performance, long-term stability, and environmental robustness remains a critical challenge, largely governed by the intrinsic properties of triboelectric materials. Recently, MXenes, a rapidly expanding family of two-dimensional transition-metal carbides, nitrides, and carbonitrides, have attracted significant attention for TENG applications owing to their exceptional electrical conductivity, tunable surface chemistry, mechanical flexibility, and abundant functional groups. This review presents a comprehensive and critical assessment of MXene-enabled TENGs, covering representative materials including Ti₃C₂T_x, Ti₃CNT_x, Nb₂CT_x, Mo₂CT_x, and V₂CT_x. This review systematically analyzes their synthesis routes, structural features, interfacial properties, and multifunctional roles in device architectures. Particular emphasis is placed on the mechanisms by which MXenes enhance triboelectric performance through dielectric modulation, charge trapping, suppression of charge recombination, moisture resistance, and enlarged effective contact area. Their versatility enables deployment as conductive electrodes, triboelectric active layers, nanocomposite reinforcements, and interfacial charge-management components. Furthermore, this review highlights emerging applications in wearable electronics, human–machine interfaces, biomedical sensing, intelligent monitoring systems, and artificial intelligence-assisted platforms. Despite remarkable advances, key challenges related to oxidation susceptibility, scalable manufacturing, cost-effectiveness, and power-density optimization continue to limit practical deployment. Finally, this study identifies critical research opportunities and future directions for MXene engineering, device design, and system integration. By elucidating the fundamental interactions between MXenes and triboelectric systems, this review establishes a roadmap for the development of high-performance, durable, and application-ready next-generation TENG technologies.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 3","pages":"Article 100204"},"PeriodicalIF":16.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review on in-situ methanation based on CO2/H2O Co-electrolysis in solid oxide electrolytic cells addressing the thermo-kinetic mismatch","authors":"Feiyang Liao ,&nbsp;Junbo Xu ,&nbsp;Chao Yang ,&nbsp;Wei Zhou","doi":"10.1016/j.enrev.2026.100188","DOIUrl":"10.1016/j.enrev.2026.100188","url":null,"abstract":"<div><div>Solid oxide electrolysis cells (SOECs) offer a compelling platform for converting renewable electricity and captured CO₂ into methane by integrating CO₂/H₂O co-electrolysis with in-situ methanation. This single-reactor concept promises process intensification, superior heat integration, and compatibility with existing natural gas infrastructure. However, its development is fundamentally constrained by the thermo-kinetic mismatch: efficient co-electrolysis typically requires temperatures above 600 °C to minimize ohmic and polarization losses, whereas methanation is thermodynamically favored below 400 °C. This review examines recent progress in direct methane synthesis within SOECs from the perspective of mitigating this mismatch systematically. We first clarify the reaction pathways, which including CO₂/H₂O electroreduction, reverse water-gas shift, methanation, carbon formation, and electrochemical promotion, and discuss the reaction mechanism of the direct methane synthesis within SOECs. Subsequently, we analyze material design strategies with emphasis on multifunctional cathodes, integration of methanation-active catalysts, and the enabling roles of oxygen electrodes and electrolytes in achieving medium-temperature operation. Reactor engineering approaches, ranging from single-temperature-zone to two-temperature-zone and thermally intensified configurations, are then evaluated to illustrate how spatial separation and flow-field regulation can enhance methane selectivity and overall efficiency. Finally, we identify key challenges and future directions in mechanistic understanding, integrated materials design, reactor optimization, and long-term durability. This review highlights that coordinated advances across reaction mechanism, thermo-electrocatalytic materials, and reactor engineering are essential to translate SOEC in-situ methanation from laboratory demonstration into practical power-to-methane applications.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 2","pages":"Article 100188"},"PeriodicalIF":0.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148168198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modification methods of carbon electrodes for vanadium redox flow batteries: Standardized testing and characterization protocols","authors":"Pitambar Poudel,&nbsp;Aaron T. Marshall","doi":"10.1016/j.enrev.2026.100191","DOIUrl":"10.1016/j.enrev.2026.100191","url":null,"abstract":"<div><div>Vanadium redox flow batteries (VRFBs) are among the most promising technologies for large-scale stationary energy storage because of their scalability, long cycle life, operational safety, flexible design and environmentally friendly operation. However, the sluggish redox kinetics and long-term instability of conventional carbon-based electrodes remain major challenges that limit their commercial deployment. Although many electrode modification strategies have been reported, direct comparison between studies is often difficult due to variations in experimental conditions, operating parameters and electrochemical evaluation methods. In many cases, modified electrodes show excellent catalytic activity in half-cell or three-electrode measurements, but these improvements do not always translate into stable long-term performance in practical full-cell systems. This limitation highlights the urgent need for standardized testing and characterization protocols in VRFB research. Recent advances in electrode engineering, including thermal and microwave treatment, chemical and electrochemical modification, defect engineering, plasma processing, heteroatom doping, incorporation of carbon nanomaterials or metal-based catalysts and ionic liquid-derived carbon materials, have demonstrated strong potential to improve catalytic activity, wettability, conductivity and cycling stability. In addition, advanced <em>in-situ</em> and operando techniques, such as electrochemical impedance spectroscopy (EIS), UV-Vis spectroscopy, Raman spectroscopy, X-ray computed tomography and synchrotron-based characterization, provide deeper understanding of electrode behavior under realistic flow battery operating conditions. This review critically summarizes recent progress in carbon electrode modification strategies, structural and electrochemical characterization methods, operando diagnostic approaches and full-cell evaluation protocols for VRFBs. A novel three-tier standardized reporting framework is proposed to improve reproducibility and enable meaningful comparison across different studies. Emphasis is placed on reporting essential operational parameters, including electrolyte composition, flow rate, current density, compression ratio and state-of-charge range. Establishing standardized testing protocols and advanced operando evaluation methods will support the rational design of durable and high-performance electrodes, thereby accelerating the practical deployment of VRFBs for large-scale renewable energy integration.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 2","pages":"Article 100191"},"PeriodicalIF":0.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148168197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in the application of high-entropy materials in lithium-based anodes","authors":"Shida Yang,&nbsp;Pengjie Ren,&nbsp;Wenqing Ruan,&nbsp;Jiang Ma","doi":"10.1016/j.enrev.2026.100193","DOIUrl":"10.1016/j.enrev.2026.100193","url":null,"abstract":"<div><div>Lithium-ion batteries constitute the cornerstone of modern energy storage. However, commercial graphite anodes are increasingly limited by their theoretical capacity and energy density. Although high-capacity alternatives such as silicon and transition metal oxides have been explored, their practical implementation remains severely bottlenecked by structural instability. High-entropy materials (HEMs) have emerged as promising candidates capable of transcending these conventional limitations. Governed by the four fundamental core effects, HEMs exhibit unique synergistic attributes, including enhanced lattice resilience and superior electrochemical kinetics, that surpass those of conventional binary or ternary counterparts. This review systematically evaluates recent progress in HEM-based anodes for lithium storage, categorizing high-entropy alloys, oxides, and burgeoning derivatives, including sulfides and phosphides. We further dissect the multifaceted storage mechanisms and the practical hurdles facing the predominant high-entropy oxide anodes. Finally, we offer forward-looking perspectives on the field, emphasizing the integration of artificial intelligence (AI) for accelerated material discovery and the pathways toward industrial-scale application.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 2","pages":"Article 100193"},"PeriodicalIF":16.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148565390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep-sea mining plume mitigation: A geotechnical perspective on sediment behavior","authors":"Fengpeng Zhang ,&nbsp;Xuguang Chen ,&nbsp;Chengwei Gao ,&nbsp;Xingyang Xie ,&nbsp;Hairui Si ,&nbsp;Qianyun Zhou ,&nbsp;Baoguo Miao","doi":"10.1016/j.enrev.2026.100189","DOIUrl":"10.1016/j.enrev.2026.100189","url":null,"abstract":"<div><div>Deep-sea mining is increasingly viewed as a potential source of critical metals needed for the global energy transition, including those used in batteries, electric mobility, renewable power systems, and grid infrastructure. The deep-sea mining faces a critical environmental challenge: sediment plumes generated by collector vehicles disturbing the seabed. These plumes, composed of fine-grained deep-sea clays, can persist for extended periods and disperse across vast oceanic areas, posing a threat to benthic ecosystems. Current plume management predominantly adopts a reactive approach, focusing on monitoring and containment rather than addressing the root cause. This paper argues that effective plume control necessitates an understanding and active management of the geotechnical properties of deep-sea sediments. We find that the unique characteristics of deep-sea sediments, including high water content, fine particle size, flocculated microstructure, high surface activity, and the interactions between particles and hydrodynamics, are not only the origin of the plume issue but also the key to its resolution. Targeting three fundamental pathways, namely reducing particle entrainment, limiting transport range, and shortening suspension duration, we propose a comprehensive mitigation framework grounded in geotechnical principles. We conclude that a transition from passive monitoring to proactive particle-level intervention is essential for reducing plume-related environmental risks and for enabling the environmentally and commercially sustainable extraction of energy-critical metals from the deep sea.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 2","pages":"Article 100189"},"PeriodicalIF":0.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148168290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon capture and conversion: A potential game changer for clean energy","authors":"Md. Sadman Anjum Joarder,&nbsp;Monjur Mourshed","doi":"10.1016/j.enrev.2026.100192","DOIUrl":"10.1016/j.enrev.2026.100192","url":null,"abstract":"<div><div>The accelerating rise in global carbon dioxide (CO₂) emissions poses a severe threat to environmental sustainability and energy security, necessitating solutions that extend beyond conventional carbon capture and storage (CCS). Carbon Capture and Conversion (CCC) has emerged as a promising alternative, enabling not only the mitigation of CO₂ emissions but also its transformation into fuels, chemicals, and materials of commercial value. This study provides a comprehensive review of CCC technologies, encompassing capture, separation, and conversion pathways, with a critical evaluation of their technology readiness levels (TRLs), energy requirements, efficiency, and cost-effectiveness. The analysis identifies key research gaps, including limited progress on industrial scalability, insufficient techno-economic and life-cycle assessments, and inadequate consideration of financial and policy frameworks necessary for commercialization. Unlike earlier reviews, this work integrates both capture and conversion perspectives, thereby offering a holistic understanding of CCC as a pathway toward sustainable industrial practices and a circular carbon economy. The findings underscore the need for coordinated efforts in catalyst development, system integration, pilot-scale demonstrations, and policy support to accelerate the practical deployment of CCC technologies in alignment with global decarbonization goals.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 2","pages":"Article 100192"},"PeriodicalIF":16.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148415286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging noble-metal-free catalysts for hydrogen technologies: Bridging theory and practice","authors":"Shiyuan Liu ,&nbsp;Jieyuan Liu ,&nbsp;Minglei Lu ,&nbsp;Yian Wang ,&nbsp;Xitang Qian","doi":"10.1016/j.enrev.2026.100176","DOIUrl":"10.1016/j.enrev.2026.100176","url":null,"abstract":"<div><div>Noble-metal-free catalysts are emerging as cost-effective, durable, and scalable alternatives to platinum-group metals (PGMs). This review surveys advances across four domains: computation, production, storage, and conversion. Computational methods, including density functional theory and machine learning, accelerate discovery by predicting adsorption energetics, identifying active sites, and guiding operando characterization. In hydrogen production, carbon materials, transition-metal oxides, phosphides, and single-atom frameworks enable efficient thermocatalytic, electrocatalytic, and photocatalytic processes, narrowing the gap with PGMs. In hydrogen storage, porous adsorbents, solid-state hydrides, and liquid organic hydrogen carriers are re-engineered with earth-abundant catalysts to improve kinetics, reversibility, and durability. In hydrogen conversion, heteroatom-doped carbons, transition-metal alloys, and M–N–C single-atom catalysts show competitive activity for the oxygen reduction and hydrogen oxidation reactions. Hybrid systems that combine trace PGMs with non-precious elements offer pragmatic pathways to commercialization. By integrating theoretical insight with experimental validation, these studies establish design principles that link electronic structure, microstructure, and performance. The target audience includes researchers and practitioners in catalysis, materials science, and energy engineering. This review provides a framework for translating noble-metal-free catalysts into scalable hydrogen technologies and reinforces hydrogen's role as a cornerstone of the global energy transition.</div></div>","PeriodicalId":100471,"journal":{"name":"Energy Reviews","volume":"5 1","pages":"Article 100176"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147547974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}