Han Pengyu, Yang Xinyi, Wu Liqing, Jia Hongnan, Luo Wei
College of Chemistry and Molecular Sciences, Wuhan University Wuhan Hubei 430072 P. R. China
Chem Sci. 2024 Mar 6;15(15):5633-5641. doi: 10.1039/d4sc00043a. eCollection 2024 Apr 17.
Encapsulating metal nanoparticles inside carbon layers is a promising approach to simultaneously improving the activity and stability of electrocatalysts. The role of carbon layer shells, however, is not fully understood. Herein, we report a study of boron doped carbon layers coated on nickel nanoparticles (Ni@BC), which were used as a model catalyst to understand the role of a bridging oxygen in a carbon shell coated Ni interface for the improvement of the hydrogen oxidation reaction (HOR) activity using an alkaline electrolyte. Combining experimental results and density functional theory (DFT) calculations, we find that the electronic structure of Ni can be precisely tailored by Ni-O-C and Ni-O-B coordinated environments, leading to a volcano type correlation between the binding ability of the OH* adsorbate and HOR activity. The obtained Ni@BC with a optimized d-band center displays a remarkable HOR performance with a mass activity of 34.91 mA mg, as well as superior stability and CO tolerance. The findings reported in this work not only highlight the role of the OH* binding strength in alkaline HOR but also provide guidelines for the rational design of advanced carbon layers used to coat metal electrocatalysts.
将金属纳米颗粒封装在碳层内部是一种有望同时提高电催化剂活性和稳定性的方法。然而，碳层壳层的作用尚未完全明确。在此，我们报道了一项关于包覆在镍纳米颗粒上的硼掺杂碳层（Ni@BC）的研究，该材料用作模型催化剂，以了解在包覆镍的碳壳界面中桥连氧对于使用碱性电解质提高氢氧化反应（HOR）活性的作用。结合实验结果和密度泛函理论（DFT）计算，我们发现Ni的电子结构可以通过Ni-O-C和Ni-O-B配位环境进行精确调控，从而导致OH吸附质的结合能力与HOR活性之间呈现火山型关联。所制备的具有优化d带中心的Ni@BC展现出卓越的HOR性能，质量活性为34.91 mA mg，同时具有出色的稳定性和抗CO能力。这项工作中报道的研究结果不仅突出了OH结合强度在碱性HOR中的作用，还为合理设计用于包覆金属电催化剂的先进碳层提供了指导。
