Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction (HER) but the effect of the crystal phase engineering of supports on their performance remains unclear. Here, the impact of the crystal phase of the support on the catalytic activity of Ru was probed by anchoring Ru nanoparticles onto precisely synthesized hexagonal (WO 3 -H), orthorhombic (WO 3 -O), and monoclinic (WO 3 -M) supports followed by thorough evaluation for HER. Among them, WO 3 -H demonstrated superior performance by providing enhanced Ru anchoring and uniform dispersion, maximizing active site availability. A critical finding is the small work function difference (Δ W F ) between Ru and WO 3 -H, which minimizes interfacial charge accumulation and facilitates efficient hydrogen spillover, thereby accelerating HER kinetics. In contrast, WO 3 -O and WO 3 -M exhibited larger Δ W F and less effective Ru dispersion, resulting in a larger hydrogen spillover barrier and suboptimal hydrogen adsorption/desorption dynamics. As a result, Ru/WO 3 -H exhibited the best performance, achieving an overpotential of 43.8 mV at 10 mA cm −2 and a Tafel slope of 49.1 mV dec −1 . This work highlights the critical role of the crystal phase in optimizing the intrinsic catalytic activity of catalysts, offering new insights for designing efficient HER catalysts.
Kai Deng,Zilong Lian,Wenxin Wang,Jiabao Yu,Qiqi Mao,Hongjie Yu,Ziqiang Wang,Liang Wang,Hongjing Wang
Despite the fruitful achievements in the development of high-performance catalysts, most of materials still suffer limited HER kinetics and poor durability in harsh acidic media, especially at high current densities . In this work, a Pd nanoparticles/Ir metallene heterojunction structure (Pd/Ir hetero-metallene) were successfully prepared by a facile co-reduction method. The hydrogen spillover bridging H + adsorption/H 2 desorption process occurring at the Pd/Ir interface results in the rate-determining step change to a Tafel step, which accelerates the HER kinetics. The Pd/Ir hetero-metallene has a relatively low Δ G Hads (-0.19 eV), which allows for rapid adsorption of H + and release of H 2 , thus greatly improving the performance of HER. As a result, the Pd/Ir hetero-metallene exhibits remarkable HER performance with ultra-low overpotentials of only 69 and 133 mV to reach 500 and 1000 mA cm −2 , a small Tafel slope of 21 mV dec −1 , and superb stability.