Influence of CeO2 on the electrocatalytic activity of nanoporous Pd-Ag catalyst toward methanol oxidation

Al-Pd-Ag-Ce precursor alloys with different Ce contents are prepared by arc melting and melt quenching methods, and the nanoporous Pd-Ag/CeO 2 catalysts are obtained by a simple dealloying treatment to investigate the electrocatalytic oxidation performance for methanol. The results show that CeO 2 exists in the form of nanorods and is uniformly distributed within the nanoporous Pd-Ag alloy matrix. When the Ce content is 0.3 at% in Al-Pd-Ag-Ce precursor alloys and the dealloying time is 12 h, the obtained nanoporous Pd-Ag/CeO 2 catalyst exhibits the best electrocatalytic performance. Compared with the commercial Pt/C and commercial Pd/C catalysts, its activity is about 8.9 times and 13.8 times, respectively, and stability is about 13.8 times and 39.1 times, respectively. These performance improvements are due to the synergistic effects at the interface between Pd and Ag, as well as between Pd and CeO 2 , the electronic effect of Ce on Pd, and the presence of oxygen vacancies on the surface of CeO 2 .