Ze Huajie, Chen Xing, Wang Xiao-Ting, Wang Yao-Hui, Chen Qing-Qi, Lin Jia-Sheng, Zhang Yue-Jiao, Zhang Xia-Guang, Tian Zhong-Qun, Li Jian-Feng
College of Energy, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, College of Materials, iChEM, Xiamen University, Xiamen 361005, China.
Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, College of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.
J Am Chem Soc. 2021 Jan 27;143(3):1318-1322. doi: 10.1021/jacs.0c12755. Epub 2021 Jan 15.
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 observations of catalytic processes.
铂镍合金催化剂具有优异的催化活性，被认为是一些最有前途的能够替代纯铂进行氧还原反应（ORR）的电催化剂。对于铂镍合金，镍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提高性能。然而，迄今为止，尚无直接的光谱证据来检测或识别镍对铂镍合金催化剂中ORR的影响。在此，我们引入一种表面增强拉曼光谱（SERS）“借用”策略来研究由金@铂镍纳米颗粒（NPs）催化的ORR过程。获得了吸附的过氧化物中间体物种（OOH）的键振动，并通过改变合金中的镍含量研究了镍对表面铂与OOH之间相互作用的影响。OOH光谱带的频率随着镍含量的增加而有明显的红移。结合密度泛函理论（DFT）计算，我们表明镍掺杂可以优化OOH在铂表面的表面结合，实现更有效的电子转移，从而提高ORR速率。值得注意的是，这些结果证明了SERS借用策略是一种用于观察催化过程的有效技术。
