Jiaxi Zhang

Ru has been investigated as a promissing hydrogen evolution reaction (HER) catalyst in anion exchange membrane water electrolyzers (AEMWEs). However, its excessive oxophilicity blocks active sites and over‐structures interfacial water, limiting alkaline HER kinetics. In this work, we report a Ru‐RuO _2−δ heterostructure that overcomes these kinetic bottlenecks via an engineered interface‐to‐surface proton transfer relay. This architecture promotes a more flexible interfacial water network that facilitates Grotthuss‐type proton transport, coupled with facilitated hydrogen spillover from high‐affinity Ru clusters to low‐affinity RuO _2−δ surfaces. By decoupling proton delivery from surface binding, the Ru‐RuO _2−δ achieves an intrinsic activity 26‐fold higher than pristine Ru, requiring ultra‐low overpotentials of only 15 ± 4 and 165 ± 6 mV at 10 and 1000 mA cm ⁻² , respectively. Notably, the catalyst demonstrates long‐term durability under high‐current‐density operation (> 470 h at 1 A cm ⁻² ) with a degradation rate 2,000‐fold lower than commercial Pt/C. In a practical AEMWE, it delivers 1 A cm ⁻² at a cell voltage of 1.67 ± 0.02 V (45.1 ± 0.5 kWh kg _H2 ⁻¹ ), meeting the U.S. DOE energy‐consumption target. Beyond providing a high‐performance alternative to platinum, this work introduces a design principle for accelerating electrocatalytic kinetics through the engineering of interface‐to‐surface transport relays.

Developing low-cost acidic oxygen evolution reaction (OER) catalysts is essential to scale proton exchange membrane water electrolysis (PEMWE). Ruthenium-based high-entropy oxides (Ru-HEOs) hold promise, yet the vast compositional space renders trial-and-error approaches inefficient. Here, we propose a data-driven, high-throughput strategy that accelerates the discovery of stable acidic OER Ru-HEO catalysts. First, literature mining with a large language model (LLM) identifies non-noble metal combinations with potential synergy with Ru. We then integrate automated powder synthesis and catalyst array fabrication to build a 60-member library. Screening using dual activity-stability metrics pinpoints the optimal composition, (RuNiFeMoCr) ₃ O ₄ . Subsequent in situ characterization and theoretical calculations show that the high-entropy environment effectively suppresses Ru dissolution and, by optimizing local coordination and electronic structure, synergistically enhances reaction kinetics and structural stability. Last, in PEMWE device tests, an electrolyzer based on this catalyst operates stably for over 150 hour at 1 A cm ⁻² , validating the data-driven strategy for accelerated screening and proof-of-concept demonstration of Ir-free anode candidates.

Despite the availability of many (oxy)hydroxide‐based oxygen evolution reaction (OER) electrocatalysts with favorable intrinsic activity, few perform well in anion exchange membrane water electrolyzers (AEMWEs). Their poor electrical conductivity confines the OER to the boundary between the current collector and electrocatalyst, resulting in poor catalyst utilization. Herein, the use of highly conductive antiperovskite nitride is proposed as a platform to develop robust OER electrodes for AEMWEs with outstanding performance. By growing over nickel foam, high catalyst surface is realized. Under operation conditions, surface reconstruction leads to the formation of a thin layer of metal oxy‐hydroxide, which acts as the real catalyst while protecting the bulk nitride from further corrosion, in turn the conductive antiperovskite effectively improves the catalyst utilization due to efficient current collection. By further rational design of the antiperovskite with a high‐entropy composition capable of selective dissolution of elements, lattice oxygen participation in the OER catalysis is enhanced, resulting in boosted intrinsic activity. Specifically, FeZnNNiCoV shows a 108‐fold increase in OER specific activity compared to low‐entropy ZnNNiCo and ultra‐high stability at 1 A cm⁻² over 1000 h. The corresponding AEMWE requires a potential of only 1.76 V to reach 1 A cm⁻², making it highly promising for practical applications.

Advancing the design of cathode catalysts to significantly maximize platinum utilization and augment the longevity has emerged as a formidable challenge in the field of fuel cells. Herein, we rationally design a high entropy intermetallic compound (HEIC, Pt(FeCoNiCu)₃) for catalyzing oxygen reduction reaction (ORR) by an efficient machine learning stategy, where crystal graph convolutional neural networks are employed to expedite the multicomponent design. Based on a dataset generated from first‐principles calculations, the model can achieve a high prediction accuracy with mean absolute errors of 0.003 for surface strain and 0.011 eV atom⁻¹ for formation energy. In addition, we identify two chemical features (atomic size difference and mixing enthalpy) as new descriptors to explore advanced ORR catalysts. The carbon supported Pt(FeCoNiCu)₃ catalyst with small particle size is successfully synthesized by a freeze‐drying‐annealing technology, and exhibits ultrahigh mass activity (4.09 A mg_Pt⁻¹) and specific activity (7.92 mA cm⁻²). Meanwhile, The catalyst also shows significantly enhanced electrochemical stability which can be ascribed to the sluggish diffussion effect in the HEIC structure. Beyond offering a promising low‐Pt electrocatalysts for fuel cell cathode, this work offers a new paradigm to rationally design advanced catalysts for energy storage and conversion devices.

Advancing the design of cathode catalysts to significantly maximize platinum utilization and augment the longevity has emerged as a formidable challenge in the field of fuel cells. Herein, we rationally design a high entropy intermetallic compound (HEIC, Pt(FeCoNiCu)₃) for catalyzing oxygen reduction reaction (ORR) by an efficient machine learning stategy, where crystal graph convolutional neural networks are employed to expedite the multicomponent design. Based on a dataset generated from first‐principles calculations, the model can achieve a high prediction accuracy with mean absolute errors of 0.003 for surface strain and 0.011 eV atom⁻¹ for formation energy. In addition, we identify two chemical features (atomic size difference and mixing enthalpy) as new descriptors to explore advanced ORR catalysts. The carbon supported Pt(FeCoNiCu)₃ catalyst with small particle size is successfully synthesized by a freeze‐drying‐annealing technology, and exhibits ultrahigh mass activity (4.09 A mg_Pt⁻¹) and specific activity (7.92 mA cm⁻²). Meanwhile, The catalyst also shows significantly enhanced electrochemical stability which can be ascribed to the sluggish diffussion effect in the HEIC structure. Beyond offering a promising low‐Pt electrocatalysts for fuel cell cathode, this work offers a new paradigm to rationally design advanced catalysts for energy storage and conversion devices.

Developing conductive electrocatalysts is crucial for decreasing the ohmic loss induced by electric resistance of the catalyst layer in the large-current-density hydrogen evolution reaction (HER), which has been overlooked previously. In this study, we screen a highly conductive antiperovskite CdNNi₃ with negligible ohmic loss, as a highly active and durable HER electrocatalyst capable of unlocking ampere-scale current densities. CdNNi₃ exhibits an impressive activity (an overpotential of 235 mV) at 1 A cm^-2 and maintains its performance steadily at an ampere-scale current density (at 1 A cm^-2 over 400 h). Besides, the CdNNi₃-enabled anion-exchange membrane water electrolyzer outperforms that of the benchmark Pt/C, evidenced by a reduced cell voltage of 160 mV at 1 A cm^-2, and presents a favorable stability at 1 A cm^-2. Importantly, this study experimentally discovers the dynamic surface reconstruction phenomena of antiperovskite nitrides during alkaline HER. Theoretical analysis suggests that the presence of Cd in the reconstructed surface effectively adjusts the local electronic configuration of active sites, which promotes the adsorption of OH and reduces the binding strength to H, thereby facilitating the water dissociation step and reducing the energy barrier of the potential-determining step in the HER process.

Building advanced catalyst supports to improve the sluggish oxygen reduction reaction (ORR) kinetics is essential to enhance fuel cell performance. However, constructing carbon supports with ideal pore structures that can reduce the mass transport resistance of oxygen while stabilising small nanoparticles (NPs) remains a challenge. Herein, we report a facile cooperative template strategy to construct a porous carbon (p-ZIF-8-C), which features a high specific surface area (1029.7 m² g⁻¹) and a unique mesoporous distribution (5–15 nm). When serving as a catalyst support, Pt NPs with an average size of ∼2.3 nm are obtained in the as-synthesized Pt/p-ZIF-8-C catalyst. Besides exhibiting a half-wave potential up to 0.915 V and excellent durability, Pt/p-ZIF-8-C achieves a significantly enhanced performance in H₂–air fuel cells with a Pt loading of 0.1 mg_Pt cm⁻² in the cathode (maximum power density of 801 mW cm⁻² and 1315 mA cm⁻² at 0.6 V). This work offers guidance for the development of advanced supports in the future.