Weiping Xiao

MSI-driven strain and charge redistribution optimize Os for balanced hydrogen conversion, while TaB ₂ -mediated hydroxyl management restructures interfacial water. This regulation accelerates Volmer kinetics and alkaline electrolysis.

The design of high‐activity single‐atom catalysts (SACs) toward two‐electron oxygen reduction is dominated by regulating the adsorption energy of *OOH intermediates at active sites, whereas the critical factor of proton activity at the catalyst–electrolyte interface has received insufficient attention. Herein, an electrode–electrolyte synergistic strategy was employed to modulate the electronic structure of Pd single‐atom sites via the construction of a Pd/CeO ₂ ‐MXene heterostructure and hydrogen bond strength using cetyltrimethylammonium bromide (CTAB) additive. X‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations revealed that the real active sites are Pd single‐atom sites anchored via Pd‐O‐Ce bonding, which significantly reduces the free energies of the key reaction steps (H ₂ O→*OOH→H ₂ O ₂ ). In situ attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) further verified that CTAB adsorbed at the reaction interface can enhance the hydrogen bond strength of interfacial water molecules, reduce the supply of interfacial *H species, and thereby effectively suppress H ₂ O ₂ decomposition. As a result, the Pd/CeO ₂ ‐MXene+CTAB system achieves a low electron transfer number of 2.02 and a high H ₂ O ₂ selectivity of 98.8% at 0.5 V. This study provides a novel insight into the rational design of proton‐coupled electrocatalysts through the integration of interfacial hydrogen bond engineering and single‐atom catalysts.

The design of high‐activity single‐atom catalysts (SACs) toward two‐electron oxygen reduction is dominated by regulating the adsorption energy of *OOH intermediates at active sites, whereas the critical factor of proton activity at the catalyst–electrolyte interface has received insufficient attention. Herein, an electrode–electrolyte synergistic strategy was employed to modulate the electronic structure of Pd single‐atom sites via the construction of a Pd/CeO ₂ ‐MXene heterostructure and hydrogen bond strength using cetyltrimethylammonium bromide (CTAB) additive. X‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations revealed that the real active sites are Pd single‐atom sites anchored via Pd‐O‐Ce bonding, which significantly reduces the free energies of the key reaction steps (H ₂ O→*OOH→H ₂ O ₂ ). In situ attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) further verified that CTAB adsorbed at the reaction interface can enhance the hydrogen bond strength of interfacial water molecules, reduce the supply of interfacial *H species, and thereby effectively suppress H ₂ O ₂ decomposition. As a result, the Pd/CeO ₂ ‐MXene+CTAB system achieves a low electron transfer number of 2.02 and a high H ₂ O ₂ selectivity of 98.8% at 0.5 V. This study provides a novel insight into the rational design of proton‐coupled electrocatalysts through the integration of interfacial hydrogen bond engineering and single‐atom catalysts.

Anion exchange membrane water electrolysis (AEMWE) stands as one of the core technologies for the hydrogen economy. In the field of cathodic electrocatalysis, most studies concentrate on optimizing the sluggish water dissociation and hydrogen adsorption kinetics of electrocatalysts yet largely overlook the site‐blocking effect caused by OH intermediate adsorption on active sites during water splitting. In this work, highly dispersed bimetallic Ru and Ni nanoclusters anchored on Tungsten carbide (WC) were synthesized via a microwave‐assisted quasi‐solid‐state route, achieving excellent hydrogen evolution reaction (HER) electrocatalytic activity in 1 m KOH. The Ru‐Ni/WC catalyst delivers a low overpotential of 29 mV at 10 mA cm ⁻² , with no appreciable activity degradation observed over long‐term continuous operation in alkaline electrolyte. Experimental characterizations and theoretical calculations unambiguously reveal that Ru‐Ni/WC facilitates the formation of an ordered yet flexible interfacial hydrogen bond network. This network not only promotes water dissociation but also enables a bidirectional spillover effect, in which adsorbed H migrates to Ru sites while adsorbed OH shuttles to Ni sites, synergistically accelerating the alkaline HER kinetics. This study offers a fresh insight into tackling the key challenges of AEMWE cathodic catalysis.

Developing cost‐effective and robust hydrogen evolution reaction (HER) catalysts to replace Pt‐based compounds in alkaline media remains a critical challenge. Therefore, FeP experiences ultrafast microwave quasi‐solid process (within 10 s) to construct a heterostructure with Os clusters (Os/FeP). Leveraging the constructed heterostructure, the occurrence of electronic metal‐support interaction (EMSI) within the fabricated Os/FeP contributes to a more rational electronic configuration, while the induced built‐in electric field (BEF) boosts electron transfer, mitigating the excessive H ^* adsorption on Os sites while enhancing H ^* coverage on FeP. The Os/FeP exhibits enhanced HER activity of 25, 36 mV@10 mA cm ⁻² in alkaline freshwater and seawater, respectively. Moreover, the assembled Os/FeP || RuO ₂ anion exchange membrane water electrolyzer (AEMWE) exhibits excellent electrocatalytic performance of 1.92 V@1 A cm ⁻² and continuously operates over 600 h under harsh industrial conditions for seawater electrolysis. The boosted mass/price activity of 9.96 A mg ⁻¹ _Os and 724.74 A dollar ⁻¹ at 2.0 V, in combination with the $0.90 H ₂ per GGE well illustrates its economic superiority, suggesting its promising prospects in industrial application. This work represents Os/FeP heterostructure catalyst with BEF and successfully utilizes the EMSI to enhance efficiency, serving as effective approaches of developing robust electrocatalysts with remarkable HER activity in alkaline media.

This review comprehensively analyzes defect engineering in electrocatalysis, covering defect classification, synthesis, dynamic evolution, and advanced applications in water electrolysis.

Metal oxides have emerged as the dominant choice of matrix for the design and synthesis of supported catalysts with high‐performance, because of the tunable surface properties, low cost, and strong interactions with active components. Herein, the nanoflower‐like titanium dioxide (TiO ₂ ) is achieved through solvothermal approach. Then, boron (B) doped black TiO ₂ loaded with Ru (Ru/B‐TiO ₂ ) is achieved through rapid (40 s) microwave quasi‐solid approach. The incorporation of B modulates the energy band structure of the electrocatalyst, creating additional active sites, and then favors the water dissociation and following hydrogen desorption. The presence of oxygen vacancy defects and metal‐support interactions (MSI) lead to satisfactory stabilization of the catalysts. These effects collectively contributed to the superior performance in 1 M KOH and alkaline seawater for the hydrogen evolution reaction (HER) with small overpotentials of 39 and 61 mV, respectively, which also demonstrates excellent activity and stability. This work presents a novel microwave‐assisted strategy for constructing metal oxide supported low‐content noble metals for energy conversion and storage applications.

The advancement of highly efficient, durable, and economically viable electrocatalysts for the hydrogen evolution reaction (HER) plays a crucial role in enabling large‐scale green hydrogen production. However, significant challenges remain in improving the efficiency of conventional catalytic processes. Here, we report osmium nanocluster‐decorated molybdenum boride (Os/MoB) as an efficient catalyst for the HER, operating via a novel hydrogen spillover mechanism. The Os/MoB catalyst achieves remarkably low overpotentials (η ₁₀ = 22, 27, and 11 mV) to reach 10 mA cm ⁻² in alkaline, acidic, and alkaline seawater (1 m KOH + seawater) electrolytes, performance that matches or surpasses commercial Pt/C. Density functional theory (DFT) calculations reveal that H ₂ O adsorbs on the MoB surface, followed by the dissociation of H ₂ O, where the generated H* species spillover to the interfacial Os sites, subsequently recombining and releasing H ₂ . Furthermore, an Os/MoB‐based anion exchange membrane water electrolyzer (AEMWE) delivers a current density of 500 mA cm ⁻² at low voltages of only 1.78 V in 1 m KOH and 1.88 V in alkaline seawater and maintains stable operation for over 100 h.

Hydrogen spillover offers a promising approach to develop highly active and affordable electrocatalysts for the hydrogen evolution reaction by regulating hydrogen migration and kinetics. Herein, a catalyst composed of osmium nanoparticles supported on zirconium dioxide (Os/ZrO₂) is designed and synthesized. The Lewis-acid-rich ZrO₂ support not only promotes water dissociation but also triggers hydrogen spillover, thereby optimizing the desorption energetics of hydrogen intermediates. Then, Os/ZrO₂ delivers outstanding HER activity in both alkaline and acidic electrolytes, requiring overpotentials of only 16 and 14 mV to reach 10 mA cm^–2, surpassing commercial Pt/C and Os/C. Mechanistic studies have confirmed the occurrence of hydrogen spillover, whereby hydrogen intermediates migrate from the Os nanoparticles to the ZrO₂ surface, effectively tuning the adsorption/desorption kinetics and leading to significantly enhanced HER performance. Furthermore, in an anion-exchange membrane electrolyzer, Os/ZrO₂||RuO₂ achieves a low voltage of 1.82 V at 1 A cm^–2 and maintains stable operation, translating to a hydrogen production cost of $0.97 per gasoline gallon equivalent. This work presents an effective strategy for designing high-performance HER catalysts through hydrogen spillover engineering, providing a feasible route for enhanced electrocatalytic systems.

The electrocatalytic performance of oxygen evolution/reduction reactions (OER/ORR) is related to the spin‐state of the transition metal, which can be modulated by magnetic element doping. This work proposes an innovative strategy involving non‐magnetic element doping to engineer spin polarization channels through the formation of Co‐O‐Ru covalent bonds, which can induce a spin‐state transition in Co sites from intermediate‐spin state () in S CoOOH to high‐spin state () in S CoOOH‐Ru. The optimized S CoOOH‐Ru achieves a remarkably low potential difference of 0.67 V between the E _1/2 for ORR and the η ₁₀ for OER, demonstrating an approximately 140 mV reduction compared with its low‐spin state S CoOOH. Density functional theory (DFT) calculation reveals that the RuO _x layer on CoO‐termination transforms CoOOH from a paramagnetic to a ferromagnetic material, indicating the generation of high‐spin Co ³⁺ sites. This optimized Co electronic structure combined with the intrinsically active Ru sites reduces free energy barriers of key ORR/OER intermediates (*OH → *O → *OOH) and accelerates the reaction kinetics, enhancing catalytic performance. This work not only unveils the remote control capability of non‐magnetic elements on spin states but also establishes a novel paradigm for spin engineering in the design of advanced oxygen electrocatalysts.