Liu Peng, Liu Huifeng, Qiu Yue, Jiang Jun, Zhong Wenhui
School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, People's Republic of China.
Grimwade Centre for Cultural Materials Conservation, School of Historical and Philosophical Studies, Faculty of Arts, University of Melbourne, Parkville, Victoria 3052, Australia.
J Phys Chem Lett. 2024 Sep 5;15(35):9003-9009. doi: 10.1021/acs.jpclett.4c02138. Epub 2024 Aug 26.
The catalytic activity and selectivity of metal single-atom catalysts strongly depend upon their spin states. However, their intrinsic connections are not yet clear. In this work, we evaluate the catalytic activity and selectivity of oxygen reduction reactions (ORRs) on CN-supporting 3d transition metal (TM = Mn/Co/Ni/Cu) single-atom catalysts (SACs) using the density functional theory calculations. It is found that all of the SACs with different spin states tend to follow the 2e HO pathway, except for CN-Mn (S = 1/2), which takes the 4e OOH pathway. Interestingly, we found that the sum of the changes in the electron spin moments of the metal active centers and the reaction intermediate OOH affects the OOH electron transfer, and the electron transfer promotes the catalytic activity of the 2e HO pathway on CN-TM SACs. Moreover, there is a strong linear relationship between the OOH electron transfer and the catalytic activity of the 2e HO pathway on CN-TM SACs. These findings indicate that electron transfer induced by the change of spin states serves as a descriptor of the catalytic activity of the 2e HO pathway on CN-TM SACs, which is very helpful for designing more powerful SACs.
金属单原子催化剂的催化活性和选择性强烈依赖于它们的自旋态。然而，它们之间的内在联系尚不清楚。在这项工作中，我们使用密度泛函理论计算评估了碳氮负载的3d过渡金属（TM = Mn/Co/Ni/Cu）单原子催化剂（SACs）上氧还原反应（ORRs）的催化活性和选择性。研究发现，除了遵循4e OOH途径的CN-Mn（S = 1/2）之外，所有具有不同自旋态的SACs都倾向于遵循2e HO途径。有趣的是，我们发现金属活性中心和反应中间体OOH的电子自旋矩变化之和影响OOH的电子转移，并且这种电子转移促进了CN-TM SACs上2e HO途径的催化活性。此外，在CN-TM SACs上，OOH电子转移与2e HO途径的催化活性之间存在很强的线性关系。这些发现表明，自旋态变化引起的电子转移可作为CN-TM SACs上2e HO途径催化活性的描述符，这对于设计更强大的SACs非常有帮助。
