Kun Xu

Herein, we report a built‐in electric field (BEF) construction strategy using Pt nanoparticles anchored on TiN supports, which drives electron redistribution at the Pt/TiN heterojunction interface, optimizing the electronic structure and enhancing charge transfer efficiency to regulate the adsorption energies of reaction intermediates (particularly NO _{x, ad} species), ultimately boosting the intrinsic catalytic activity. Notably, Pt/TiN catalyst achieved a peak current of nearly 120 A g ⁻¹ during AOR, which is more than twice that of commercial Pt/C and approximately four times that of Pt/TiO ₂ . Furthermore, both experimental and theoretical results indicate that the work function differences induce a pronounced BEF, which drives interfacial electron transfer, leading to Fermi level alignment and the formation of Pt regions characterized by electron accumulation. More importantly, a rechargeable Zn─NH ₃ battery was constructed, delivering a Faradaic efficiency as high as 94.2% and enabling continuous NH ₃ ‐mediated H ₂ production for 30 h at 8 mA cm ⁻² , thereby laying a solid foundation for practical applications. This work introduces an innovative approach to BEF construction for regulating the electronic structure of Pt, thereby advancing electrocatalysis in energy conversion.

Ammonia oxidation reaction (AOR) is critical for efficient ammonia utilization as a hydrogen carrier, yet state‐of‐the‐art Pt‐based catalysts suffer significant activity loss due to strong ^* NO _x species ( ^* NO, ^* NO ₂ ) adsorption. Herein, Pd@Pt mesoporous core‐shell nanospheres with interstitial Co in Pt shell (Pd@Pt‐Co MCSN) are demonstrated as an excellent AOR electrocatalyst, which achieves a mass activity of 293.6 A g ⁻¹ at 0.7 V versus RHE, 4.8‐fold higher than commercial Pt/C. The interstitial Co dopant tunes the d‐d orbital hybridization state, optimizes the Pt d‐band center position, and facilitates electron transfer from Co to Pt, which effectively weakens the adsorption of toxic ^* NO _x and lowers the energy barrier for N‐N coupling. When integrated into a Zn‐NH ₃ battery, the catalyst enables efficient NH ₃ ‐to‐H ₂ conversion with a Faradaic efficiency of 96.8% and stable operation for 30 hours at 12 mA cm ⁻² . The work may provide a new design concept to develop advanced electrocatalysts for AOR.

Ammonia oxidation reaction (AOR) is important for enabling the efficient use of NH ₃ as a promising carrier for hydrogen storage and transportation. However, the catalytic activity of state‐of‐the‐art Pt‐based catalysts decreases significantly due to the strong adsorption of N species. In this study, a triple‐layer core–shell structured Ru@Ir@Pt model catalyst was employed to demonstrate that the relay electron transfer strategy can decelerate the adsorption of N species and increase AOR activity, a process facilitated by the built‐in electric field (BEF) induced by differing work functions that drive the sequential relay of charge transfer across the interfaces between different metals. In situ Fourier Transform Infrared (FTIR) spectroscopy revealed that AOR proceeds primarily via the N ₂ H ₄ pathway of the G–M mechanism. Both the experimental and theoretical simulation results confirm that relay electron transfer induced by a built‐in electric field enables the outermost Pt electron‐rich state to reduce the intensity of N adsorbed species and lower the energy barrier of rate‐determining step in the AOR, resulting in excellent activity with a mass activity reaching up to 363.5 A g ⁻¹ . This value is 5.24 times higher than that of 20% Pt/C and significantly surpasses most previously reported catalysts. This work presents a novel material design approach for developing high‐performance advanced ammonia oxidation electrocatalysts.

Ammonia oxidation reaction (AOR) is important for enabling the efficient use of NH ₃ as a promising carrier for hydrogen storage and transportation. However, the catalytic activity of state‐of‐the‐art Pt‐based catalysts decreases significantly due to the strong adsorption of N species. In this study, a triple‐layer core–shell structured Ru@Ir@Pt model catalyst was employed to demonstrate that the relay electron transfer strategy can decelerate the adsorption of N species and increase AOR activity, a process facilitated by the built‐in electric field (BEF) induced by differing work functions that drive the sequential relay of charge transfer across the interfaces between different metals. In situ Fourier Transform Infrared (FTIR) spectroscopy revealed that AOR proceeds primarily via the N ₂ H ₄ pathway of the G–M mechanism. Both the experimental and theoretical simulation results confirm that relay electron transfer induced by a built‐in electric field enables the outermost Pt electron‐rich state to reduce the intensity of N adsorbed species and lower the energy barrier of rate‐determining step in the AOR, resulting in excellent activity with a mass activity reaching up to 363.5 A g ⁻¹ . This value is 5.24 times higher than that of 20% Pt/C and significantly surpasses most previously reported catalysts. This work presents a novel material design approach for developing high‐performance advanced ammonia oxidation electrocatalysts.

Modulation of the surface structure of high-entropy-alloy-based nitrides (HEANs) is considered essential for improving electrocatalytic H₂ production. Compared with thermal nitridation, the plasma technique is a favorable alternative to directly fabricate HEANs, but the excessive surface heating effect during plasma treatment inevitably causes thermally stabilized nitride formation, resulting in deterioration of the highly active structure. To optimize the hydrogen evolution reaction (HER) behavior of HEANs, a facile cooling-mediated plasma strategy is proposed to precisely modulate the HEAN structure (cp-HEAN). The resultant cp-HEAN framework shows a preserved FCC (111) facet and yields an increased amorphous proportion, leading to enhanced HER behavior. In comparison, the normal plasma technique causes FCC lattice distortion with increased precipitation owing to the excessively high surface thermal field (np-HEAN). Operando plasma diagnostics and numerical simulation further confirmed the effect of surface heating on typical plasma parameters and the HEAN framework, indicating that this was the key factor responsible for the high performance of the nitride electrocatalyst.

Developing highly active and CO‐resistant Ru‐based catalysts for the alkaline hydrogen oxidation reaction (HOR) can advance the large‐scale application of alkaline hydrogen fuel cells but remains a huge challenge. Herein, a pure phase W₂C supported Ru cluster catalyst (Ru/W₂C) is successfully synthesized through a one‐step carburization method. It is found that the charge transfer from W₂C to the strongly anchored Ru clusters forms the electron‐rich Ru^δ− sites and electron‐deficient W^δ+ sites, which significantly weakens the adsorption strength of ^*H and ^*CO, strengthens the binding of ^*OH and improves the water connectivity in the electric double layer. The Ru/W₂C catalyst shows superior mass activity (2163 mA mg_PGM⁻¹) in alkaline HOR, which is 12.52 and 20.62 times higher than that for Pt/C and Ru/C, respectively. Owing to the weak adsorption and fast removal rate of CO, the Ru/W₂C exhibits outstanding CO tolerance, with 88% of the initial activity being retained in the durability test, whereas the Ru/C and Pt/C suffer from severe deactivation. These findings may guide the design of advanced alkaline HOR catalysts based on the pure phase tungsten carbide.

Understanding the phase structure‐dependent catalytic performance is of great significance for the investigation of advanced electrocatalysts. At present, research in phase engineering of metal materials for electrocatalysis predominantly concentrates on the iron group, platinum group, and coinage group metals with A1‐, A2‐, and A3‐ type structures. However, the investigation of metal phase engineering beyond the above metal group with other types of structures for electrocatalysis is still poorly explored. Herein, using tungsten as a substrate to support iridium, it is shown that iridium‐embedded tungsten with diverse crystal phase structure (referred to as Ir/α‐W for A2‐type structure and Ir/β‐W for A‐15 type structure) exhibits distinct catalytic activity for hydrogen oxidation reactions (HOR) in alkaline medium. Notably, the mass‐normalized exchange current density (j _{0, m} ) of noble metal iridium in Ir/α‐W (518.3 A g ⁻¹ _Ir ) is ≈1.8 times and 16.4 times higher than that of Ir/β‐W and Ir/C, respectively. In‐depth mechanistic studies suggest that the enhanced HOR performance on Ir/α‐W is attributed to the enhanced connectivity of the H‐bond network as well as the synergistic optimization of the adsorption binding energies of H and OH intermediate species. This study can inspire more scientific interest on the exploration of metal phase engineering for electrocatalysis.

The electrochemical oxidation of amines has emerged as a promising alternative to traditional energy‐intensive industrial processes for the green synthesis of nitriles, and the rational design of efficient electrocatalysts is crucial due to the sluggish reaction kinetics. Herein, it is reported that modulating the topological order within the same structural unit can boost catalytic activity for the electrooxidation of benzylamine to benzonitrile (BOR). Using nickel nitride as a model, Cu atoms are introduced into the pristine N─Ni structural framework, inducing a change in the topological order of the structural units and resulting in the formation of Ni₃CuN with an antiperovskite structure. As a result, the antiperovskite Ni₃CuN exhibits a 2‐fold enhancement of BOR activity compared to Ni₃N, despite the fact that the N─Ni coordination polyhedra of both are almost identical. Theoretical calculations demonstrate that the modulation strategy of the topological order of the same structural units successfully weakens the Ni─N bonding interactions, induces the downward shift of the d‐band centers, and optimizes the desorption of the reaction products, which ultimately contributes to the more superior electrocatalytic activity of Ni₃CuN. This work provides a new perspective on developing advanced electrocatalysts through the structural topological order modulation.

The precise fabrication and regulation of the stable catalysts with desired performance still challengeable for single atom catalysts. Here, the Ru single atoms with different coordination environment in Ni₃FeN lattice are synthesized and studied as a typical case over alkaline methanol electrooxidation. The Ni₃FeN with buried Ru atoms in subsurface lattice (Ni₃FeN-Ru_buried) exhibits high selectivity and Faradaic efficiency of methanol to formate conversion. Meanwhile, operando spectroscopies reveal that the Ni₃FeN-Ru_buried exhibits an optimized adsorption of reactants along with an inhibited surface structural reconstruction. Additional theoretical simulations demonstrate that the Ni₃FeN-Ru_buried displays a regulated local electronic states of surface metal atoms with an optimized adsorption of reactants and reduced energy barrier of potential determining step. This work not only reports a high-efficient catalyst for methanol to formate conversion in alkaline condition, but also offers the insight into the rational design of single atom catalysts with more accessible surficial active sites.