氢能是清洁和理想的零碳排放能源之一。利用电催化分解水生产氢能具有能耗低、过程环保、产品纯度高以及能量转化效率高等优点，是一种大有前景的能源存储和转化方式。其中最关键的问题是寻找可替代贵金属铂的低成本、高活性的电催化剂。目前报道的大部分单组分电催化剂，其活性受限于自身固有的氢吸附自由能；而开发多组分多界面复合型电催化剂有望改善材料的氢吸附能，并实现催化剂产氢性能的突破。近日，东北师范大学化学学院多酸科学教育部重点实验室在该领域取得重要研究进展。

实验室博士生马媛媛作为研究工作第一作者，博士后郎中玲作为共同第一作者，以过渡金属取代型多酸作为催化剂分子设计平台，利用多酸中天然的准界面结构原位塌陷，成功制备出一种纳米尺寸多界面的镍碳化物复合电催化剂Ni/WC@NC（如图1所示）。这种多界面的Ni/WC@NC催化剂具备低成本、催化活性优良、稳定性好等优点，可应用于全pH范围产氢。研究工作首次通过原位同步辐射实验、理论计算和旋转环盘电极实验共同揭示了镍与碳化钨多界面结构之间的电子转移与质子传递过程是催化剂提高活性的关键，而界面的增加将是复合型电催化剂性能提高的重要设计路径。该工作发表于国际著名化学类杂志《能源与环境科学》上 (High efficient hydrogen evolution triggered by a multi-interfacial Ni/WC hybrid electrocatalyst, Energy Environ. Sci., 2018, 11, 2114 – 2123；IF = 30.067)，该论文是在李阳光教授和谭华桥副教授研究团队指导下与苏州大学康振辉和钟俊教授课题组共同合作完成的。

图1 由{Ni₅₄W₇₂}多酸制备Ni/WC@NC电催化剂用于电解水产氢研究

A New Progress in Polyoxometalate-Mediated High Efficient Noble-Metal-Free Electrocatalysts for Hydrogen Evolution Reaction

Hydrogen energy as a kind of zero-carbon emission energy has been considered as one of the cleanest energies. Hydrogen evolution reaction (HER) based on water electrolysis is a promising pathway for sustainable hydrogen production, owing to their low energy consumption, environmental-friendly process, pure products and high energy conversion efficiency. The important task in water splitting for hydrogen is developing low cost, high active and stable electrocatalysts. Recently, a research team in Northeast Normal University, Department of Chemistry has made an important breakthrough in this field.

The Ph. D student Yuan-yuan Ma as the first author and the postdoc Zhong-ling Lang as the co-first author employed the transition metal-substituted POM (Ni₅₄W₇₂) as precursor, which possess the natural quasi interfaces between different metal-oxo fragments in Ni₅₄W₇₂, and successfully prepared a new type of multi-interfacial nickel/tungsten carbide (Ni/WC) hybrid nanoparticles (NPs) anchoring on N-doped carbon sheets (Ni/WC@NC) (Figure 1). Such low-cost Ni/WC@NC electrocatalyst exhibits high activity and remarkable stability, and could be applied in wide range of pH. DFT calculations and in-situ XAS measurements reveal that the remarkable HER activity is mainly attributed to abundant interfaces between Ni and WC domains, which induces a synergistic optimization of the electronic configuration of Ni and WC through electron transfer process from WC to Ni along with potential mass transport, thus promoting the HER kinetics and accelerating the reaction. This work provides a new option for the design and preparation of promising HER electrocatalysts, and has been published in the flagship journal of RSC, Energy ＆ Environmental Science (High efficient hydrogen evolution triggered by a multi-interfacial Ni/WC hybrid electrocatalyst, Energy Environ. Sci., 2018, 11, 2114 - 2123). The correspondence authors are Professor Yang-Guang Li and associate Professor Hua-Qiao Tan from Northeast Normal University and Professor Zhen-Hui Kang and Jun Zhong from Soochow University.

Figure 1 Schematic view of the Ni/WC@NC prepared from {Ni₅₄W₇₂} POM as new type of HER electrocatalyst