MOFs-derived TiO2 on N-doped carbon materials with high concentration of oxygen vacancies as Pt supports and co-catalysts for methanol electrooxidation

Abstract

MIL-125(Ti)–NH2 was pyrolyzed in N2 and H2/Ar gas to prepare N-doped carbon materials containing TiO2 (TiO2-NC). XPS, ESR and Raman spectra analysis showed that higher concentration of oxygen vacancies were created on the surface of TiO2 in H2/Ar gas, which provided more anchor sites for the nucleation of Pt and enhanced the interaction between Pt and TiO2. Therefore, the mass activity/specific activity of Pt/(TiO2-NC)HA catalysts for methanol oxidation was 510.7 mA mg−1Pt/2.84 mA cm−2Pt, which was 3.1/1.4 times that of Pt/(TiO2-NC)N catalysts. Due to the enriched OHads on the suface of TiO2 and the strong metal-support interaction between TiO2 and Pt, Pt/(TiO2-NC)HA catalysts exhibited stronger resistance to COads poisoning than commercial JM-Pt/C catalysts, thus showing more excellent catalytic activity and stability.