Alloying Nickel with Molybdenum Significantly Accelerates Alkaline Hydrogen Electrocatalysis
Miao Wang,+,1 Hao Yang,+,1 Jinan Shi,2 Yufeng Chen,1 Yuan Zhou, 1 Liguang Wang,3 Sijia Di,1 Xuan Zhao,1 Jun Zhong,1 Tao Cheng,1 Wu Zhou,2 and Yanguang Li*,1
1Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nanoscience and Technology, Soochow University, 199 Ren-Ai Road, Suzhou 215123, China.
2School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 (China)
3Key Laboratory of Carbon Materials of Zhejiang Province, Institute of New Materials and Industrial Technologies, Wenzhou University Wenzhou, Zhejiang 325035 (China), and Department of Chemistry and Biochemistry, University of Windsor Windsor, ON N9B3P4 (Canada)
Bifunctional hydrogen electrocatalysis (hydrogenoxidation and hydrogen-evolution reactions) in alkaline solution is desirable but challenging. Among all available electrocatalysts, Ni-based materials are the only non-precious-metal-based candidates for alkaline hydrogen oxidation, but they generally suffer from low activity. Here, we demonstrate that properly alloying Ni with Mo could significantly promote its electrocatalytic performance. Ni4Mo alloy nanoparticles are prepared from the reduction of molybdate-intercalated Ni(OH)2 nanosheets. The final product exhibits an apparent hydrogen-oxidation activity exceeding that of the Pt benchmark and a record-high mass-specific kinetic current of 79 Ag-1 at an over potential of 50 mV. A superior hydrogen- evolution performance is also measured in alkaline solution. These experimental data are rationalized by our theoretical simulations, which show that alloying Ni with Mo significantly weakens its hydrogen adsorption, improves the hydroxyl adsorption and decreases the reaction barrier for water formation.