Crystalline Phase Engineering to Modulate the Interfacial Interaction of the Ruthenium/Molybdenum Carbide for Acidic Hydrogen Evolution
Yuze Li, Zhenlan Dou, Yongyu Pan, Hao Zhao, Longping Yao, Qiansen Wang, Chunyan Zhang, Zhouying Yue, Zhiqing Zou, Qingqing Cheng, Hui Yang
Abstract
Ruthenium (Ru) is an ideal substitute to commercial Pt/C for the acidic hydrogen evolution reaction (HER), but it still suffers from undesirable activity due to the strong adsorption free energy of H* (Δ G H* ). Herein, we propose crystalline phase engineering by loading Ru clusters on precisely prepared cubic and hexagonal molybdenum carbide (α-MoC/β-Mo 2 C) supports to modulate the interfacial interactions and achieve high HER activity. Advanced spectroscopies demonstrate that Ru on β-Mo 2 C shows a lower valence state and withdraws more electrons from the support than that of Ru on α-MoC, indicative of a strong interfacial interaction. Density functional theory reveals that the Δ G H* of Ru/β-Mo 2 C approaches 0 eV, illuminating an enhancement mechanism at the Ru/β-Mo 2 C interface. The resultant Ru/β-Mo 2 C exhibits an encouraging performance in a proton exchange membrane water electrolyzer with a low cell voltage (1.58 V@ 1.0 A cm –2 ) and long stability (500 h@ 1.0 A cm –2 ).