Mesoporous PdAg Nanospheres for Stable Electrochemical CO2 Reduction to Formate
Yuan Zhou,1 Rui Zhou,1 Xiaorong Zhu,2 Na Han,1 Bin Song,1 Tongchao Liu,3 Guangzhi Hu,4 Yafei Li,2 Jun Lu,*,1and Yanguang Li*,1
1Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Soochow University Suzhou 215123, China
2College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China
3Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA.
4Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650504, China
Palladium is a promising material for electrochemical CO2reduction to formate with high Faradaic efficiency near the equilibrium potential. It unfortunately suffers from problematic operation stability due to CO poisoning on surface. Here, it is demonstrated that alloying is an effective strategy to alleviate this problem. Mesoporous PdAg nanospheres with uniform size and composition are prepared from the co-reduction of palladium and silver precursors in aqueous solution using dioctadecyldimethylammonium chloride as the structure-directing agent. The best candidate can initiate CO2 reduction at zero overpotential and achieve high formate selectivity close to 100% and great stability even at <-0.2 V versus reversible hydrogen electrode. The high selectivity and stability are believed to result from the electronic coupling between Pd and Ag, which lowers the d-band center of Pd and there by significantly enhances its CO tolerance, as evidenced by both electrochemical analysis and theoretical simulations.