北京科技大学邢献然团队报道了双金属纳米催化剂析氢反应的局部结构。相关研究成果于2022年10月27日发表在国际顶尖学术期刊《美国化学会杂志》。

亚5nm双金属纳米催化剂的原子3D结构的揭示对突破传统方法的局限性具有重要意义。值得注意的是，催化反应期间活性位点和附近配位环境之间的协同关系的确定，取决于局部相的立体分布和短范围内的化学组成。

作为研究中的模型纳米催化剂，研究人员研究了析氢反应（HER）中的有序PtFe双金属。通过将配对分布函数与逆蒙特卡罗相结合，确定了局部范围相对称性、化学成分和原子分布。作为无序富Pt A1和Pt3Fe L12相的局部相段的偏析是由于Pt56Fe44中HER活性和稳定性的显著提高。在蚀刻最外表面Fe之后，剩余的无序偏析为放电和电化学解吸反应提供了大量活性Pt位点。它产生了局部键合的铂对，使吸附的氢原子更容易重组。

该研究将为双金属纳米催化剂的局部范围提供结构见解，并对创造新的低成本纳米催化剂具有价值。

附：英文原文

Title: Local Structure Insight into Hydrogen Evolution Reaction with Bimetal Nanocatalysts

Author: Qiang Li, He Zhu, Xiaoyu Chen, Hui Liu, Yang Ren, Yanan Chen, Koji Ohara, Lihui Zhou, Jun Chen, Jinxia Deng, Jun Miao, Kun Lin, Xiaojun Kuang, Xianran Xing

Issue&Volume: October 27, 2022

Abstract: The revelation of the atomic 3D structure of sub-5 nm bimetal nanocatalysts challenges the limitations of conventional methods. Notably, the identification of the cooperative relationship between the active sites and nearby coordination environment during catalytic reactions depends on the stereo distribution of local phases and chemical composition within a short range. As a model nanocatalyst in our investigation, we studied the ordered PtFe bimetals in hydrogen evolution reactions (HER). By combining pair distribution functions with reverse Monte Carlo, local-range phase symmetry, chemical composition, and atom distribution were determined. The segregation of local phase segments as disordered Pt-rich A1 and Pt3Fe L12 phases can be attributed to the marked improvement of HER activity and stability in Pt56Fe44. Following the etching of the outermost-surface Fe, the remaining disordered segregation offered a large number of active Pt sites for discharge and electrochemical desorption reactions. It resulted in local-bonding Pt pairs that made it easier for adsorbed hydrogen atoms to recombine. The current research will provide structural insight into the local range for bimetal nanocatalysts and be valuable for the creation of new, low-cost nanocatalysts.

DOI: 10.1021/jacs.2c07844

Source: https://pubs.acs.org/doi/10.1021/jacs.2c07844