Li Xiyu, Zhong Wenhui, Cui Peng, Li Jun, Jiang Jun
Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Hefei Science Center of CAS, School of Chemistry and Materials Science, University of Science and Technology of China , Hefei, Anhui 230026, P. R. China.
Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Institute of Applied Physics, Guizhou Synergetic Innovation Cen-ter of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Normal College , Gaoxin Road 115, Guiyang, Guizhou 550018, P. R. China.
J Phys Chem Lett. 2016 May 5;7(9):1750-5. doi: 10.1021/acs.jpclett.6b00096. Epub 2016 Apr 27.
Heterogeneous catalysis often involves molecular adsorptions to charged catalyst site and reactions triggered by catalyst charges. Here we use first-principles simulations to design oxygen reduction reaction (ORR) catalyst based on double transition metal (TM) atoms stably supported by 2D crystal C2N. It not only holds characters of low cost and high durability but also effectively accumulates surface polarization charges on TMs and later deliveries to adsorbed O2 molecule. The Co-Co, Ni-Ni, and Cu-Cu catalysts exhibit high adsorption energies and extremely low dissociation barriers for O2, as compared with their single-atom counterparts. Co-Co on C2N presents less than half the value of the reaction barrier of bulk Pt catalysts in the ORR rate-determining steps. These catalytic improvements are well explained by the dependences of charge polarization on various systems, which opens up a new strategy for optimizing TM catalytic performance with the least metal atoms on porous low-dimensional materials.
多相催化通常涉及分子吸附到带电的催化剂位点以及由催化剂电荷引发的反应。在此，我们使用第一性原理模拟来设计基于二维晶体C2N稳定支撑的双过渡金属（TM）原子的氧还原反应（ORR）催化剂。它不仅具有低成本和高耐久性的特点，还能有效地在过渡金属上积累表面极化电荷，并随后传递给吸附的O2分子。与单原子对应物相比，Co-Co、Ni-Ni和Cu-Cu催化剂对O2表现出高吸附能和极低的解离能垒。在ORR速率决定步骤中，C2N上的Co-Co的反应势垒值不到块状Pt催化剂的一半。电荷极化对各种体系的依赖性很好地解释了这些催化性能的提升，这为在多孔低维材料上用最少的金属原子优化过渡金属催化性能开辟了一条新策略。
