Hao Zhaomin, Yang Shishuai, Niu Jingyang, Fang Zhiqiang, Liu Liangliang, Dong Qingsong, Song Shuyan, Zhao Yong
Henan Key Laboratory of Polyoxometalate Chemistry , College of Chemistry and Chemical Engineering , Henan University , Kaifeng , 475004 , Henan Province , P. R. China . Email:
Key Lab for Special Functional Materials of Ministry of Education , Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng , 475004 , Henan Province , P. R. China . Email:
Chem Sci. 2018 May 28;9(25):5640-5645. doi: 10.1039/c8sc01710g. eCollection 2018 Jul 7.
Transition-metal Mo-based materials have been considered to be among the most effective hydrogen evolution reaction (HER) electrocatalysts. Regulating the electronic structure of Mo atoms with guest metal atoms is considered as one of the important strategies to improve their HER activity. However, introduction of guest metal elements in the vicinity of Mo sites with atomic-level hybridization is difficult to realize, resulting in the failure of the modified electronic structure of Mo sites. Herein, an FeMoO/MoO material is prepared through the thermal treatment of a ferrimolybdate precursor. It exhibits a Tafel slope of 79 mV dec and an exchange current density of 0.069 mA cm in 1 M KOH medium, as well as a Tafel slope of 47 mV dec and an exchange current density of 0.072 mA cm in 0.5 M HSO medium. Compared to original Mo-based oxides, FeMoO with the regulated Mo electronic structure shows a more suitable Mo-H bond strength for the fast kinetics of the HER process. Density functional theory (DFT) calculations also indicate that the Mo-H bond strength in FeMoO is similar to the Pt-H bond strength, resulting in the high kinetic activity of Mo-based HER electrocatalysts in alkaline and acidic media.
过渡金属钼基材料被认为是最有效的析氢反应（HER）电催化剂之一。用客体金属原子调节钼原子的电子结构被认为是提高其析氢活性的重要策略之一。然而，在原子级杂化的钼位点附近引入客体金属元素很难实现，导致钼位点的电子结构改性失败。在此，通过对铁钼酸盐前驱体进行热处理制备了FeMoO/MoO材料。在1 M KOH介质中，它的塔菲尔斜率为79 mV dec，交换电流密度为0.069 mA cm；在0.5 M H₂SO₄介质中，塔菲尔斜率为47 mV dec，交换电流密度为0.072 mA cm。与原始的钼基氧化物相比，具有调节后的钼电子结构的FeMoO对于析氢过程的快速动力学表现出更合适的Mo-H键强度。密度泛函理论（DFT）计算还表明，FeMoO中的Mo-H键强度与Pt-H键强度相似，这导致钼基析氢电催化剂在碱性和酸性介质中具有高动力学活性。
