Pu Yixuan, Chen Jia-Lan, Zhao Jian-Wen, Feng Li, Zhu Jinze, Jiang Xuechun, Li Wei-Xue, Liu Jin-Xun
Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China.
JACS Au. 2024 Jul 26;4(8):2886-2895. doi: 10.1021/jacsau.4c00116. eCollection 2024 Aug 26.
The development of alternative alloy catalysts with high activity, surpassing platinum group metals, for the oxygen reduction reaction (ORR) is urgently needed in the field of electrocatalysis. The Ag-based single-atom alloy (AgSAA) cluster has been proposed as a promising catalyst for the ORR; however, enhancing its activity under operational conditions remains challenging due to limited insights into its actual active site. Here, we demonstrate that the operando formation of the MO (OH) complex serves as the key active site for catalyzing the ORR over AgSAA cluster catalysts, as revealed through comprehensive neural network potential molecular dynamics simulations combined with first-principles calculations. The volcano plot of the ORR over the MO (OH) complex addresses the gaps inherent in traditional metallic alloy models for pure AgSAA cluster catalysts in ORR catalysis. The appropriate orbital hybridization between OH and the dopant metal in the MO (OH) complexes indicated that the AgCo, AgPd, and AgAu clusters are optimal AgSAA catalysts for the ORR. Our work underscores the significance of theoretical modeling considering the reaction atmosphere in uncovering the true active site for the ORR, which can be extended to other reaction systems for rational catalyst design.
在电催化领域，迫切需要开发出具有高活性、超越铂族金属的用于氧还原反应（ORR）的替代合金催化剂。基于银的单原子合金（AgSAA）簇已被提议作为一种有前景的ORR催化剂；然而，由于对其实际活性位点的认识有限，在操作条件下提高其活性仍然具有挑战性。在这里，我们通过综合神经网络势分子动力学模拟结合第一性原理计算表明，MO(OH)络合物的原位形成是催化AgSAA簇催化剂上ORR的关键活性位点。MO(OH)络合物上ORR的火山图解决了纯AgSAA簇催化剂在ORR催化中传统金属合金模型固有的差距。MO(OH)络合物中OH与掺杂金属之间适当的轨道杂化表明，AgCo、AgPd和AgAu簇是ORR的最佳AgSAA催化剂。我们的工作强调了考虑反应气氛的理论建模在揭示ORR真正活性位点方面的重要性，这可以扩展到其他反应系统以进行合理的催化剂设计。
