厦门大学的李剑锋团队使用原位SERS借用策略探讨Ni在Pt基纳米催化剂中改善氧还原反应的关键作用。相关研究成果于2021年1月15日发表在《美国化学会杂志》。

PtNi合金催化剂具有优良的催化活性，被认为是最有希望取代纯Pt用于氧还原反应（ORR）的电催化剂之一。对于PtNi合金，Ni掺杂可以通过改变催化剂表面的电子和结构性质及其与反应中间体的相互作用来改善其性能。然而，迄今为止还没有直接的光谱证据检测或鉴定镍对PtNi合金催化剂ORR的影响。

该文中，研究人员介绍了一种表面增强拉曼光谱（SERS）“借用”策略来研究Au@PtNi 纳米颗粒 (NPs)催化的ORR过程。通过改变合金中Ni的含量，研究了Ni对表面Pt与*OOH相互作用的影响。随着Ni含量的增加，*OOH谱带的频率有明显的红移。结合密度泛函理论（DFT）计算，研究人员发现Ni掺杂可以优化Pt表面的*OOH表面结合，实现更有效的电子转移，从而提高ORR率。

值得注意的是，这些结果证明SERS借用策略是一种原位观察催化过程的有效技术。

附：英文原文

Title: Molecular Insight of the Critical Role of Ni in Pt-Based Nanocatalysts for Improving the Oxygen Reduction Reaction Probed Using an In Situ SERS Borrowing Strategy

Author: Huajie Ze, Xing Chen, Xiao-Ting Wang, Yao-Hui Wang, Qing-Qi Chen, Jia-Sheng Lin, Yue-Jiao Zhang, Xia-Guang Zhang, Zhong-Qun Tian, Jian-Feng Li

Issue&Volume: January 15, 2021

Abstract: PtNi alloy catalysts have excellent catalytic activity and are considered some of the most promising electrocatalysts capable of replacing pure Pt for the oxygen reduction reaction (ORR). For PtNi alloys, Ni-doping can improve performance by changing the electronic and structural properties of the catalyst surface and its interaction with reaction intermediates. However, to date there is no direct spectral evidence detecting or identifying the effect of Ni on the ORR in PtNi alloy catalysts. Herein, we introduce a surface-enhanced Raman spectroscopic (SERS) “borrowing” strategy for investigating ORR processes catalyzed by Au@PtNi nanoparticles (NPs). The bond vibration of adsorbed peroxide intermediate species (*OOH) was obtained, and the effect of Ni on the interaction between surface Pt and *OOH was studied by varying the Ni content in the alloy. The frequency of the *OOH spectral band has an obvious red-shift with increasing Ni content. Combined with density functional theory (DFT) calculations, we show that Ni-doping can optimize *OOH surface binding on the Pt surface, achieving more efficient electron transfer, thus improving the ORR rate. Notably, these results evidence the SERS borrowing strategy as an effective technique for in situ observations of catalytic processes.

DOI: 10.1021/jacs.0c12755

Source: https://pubs.acs.org/doi/10.1021/jacs.0c12755