Achieving Superior Electrocatalytic Performance by Surface Copper Vacancy Defects during Electrochemical Etching Process. (12th May 2020) - Guo, Niankun
Abstract: Vacancy defects of catalysts have been extensively studied and proven to be beneficial to various electrocatalytic reactions. Herein, an ultra‐stable three‐dimensional PtCu nanowire network (NNW) with ultrafine size, self‐supporting rigid structure, and Cu vacancy defects has been developed. The vacancy defect‐rich PtCu NNW exhibits an outstanding performance for the oxygen reduction reaction (ORR), with a mass activity 14.1 times higher than for the commercial Pt/C catalyst (20 %.wt, JM), which is currently the best performance. The mass activity of the PtCu NNW for methanol oxidation reaction (MOR) is 17.8 times higher than for the commercial Pt/C catalyst. Density‐functional theory (DFT) calculations indicate that the introduction of Cu vacancies enhances the adsorption capacity of Pt atoms to the HO* intermediate and simultaneously weakens the adsorption for the O* intermediate. This work presents a facile strategy to assemble efficient electrocatalysts with abundant vacancy defects, at the same time, provides an insight into the ORR mechanism in acidic solution. Abstract : Vacancy defect‐rich Pt‐Cu nanowire networks (VCu ‐PtCu) exhibit superior electrocatalytic performance for the oxygen reduction reaction, in which the mass activity is 14.1 times higher than for commercial Pt/C (20 %.wt, JM), and is currently the best performance among unsupported Pt‐based nanomaterials. The Tafel plot shows that VCu ‐PtCu delivers a mass activity (MA) 7.2 times higher than the 2020 target set by the US Department of Energy (DOE).