Simple synthesized Pt/GNs/TiO2 with good mass activity and stability for methanol oxidation

摘要

Pt/GNs/TiO2 (GNs, graphene nanosheets) catalyst was synthesized by a simple two-step method, including a rapid solution plasma technique to obtained Pt nanoparticles with a size of 2-5 nm and followed by an ultrasonic mixing of the Pt, GNs and TiO2 nanoparticles. After coupling with TiO2 nanoparticles, the Pt/GNs/TiO2 catalyst exhibited a promoting catalytic activity towards methanol oxidation, which was superior to the Pt/GNs catalyst. The mass activity of the Pt/GNs/TiO2 catalyst was 3464 mA mg(Pt)(-1), which was 3.5 and 3.4 times higher than those of the Pt/GNs and the commercial Pt/C, respectively. And the Pt/GNs/TiO2 showed a strongly negative shift onset potential of methanol oxidation. The results of long-term cyclic voltammetry and CO-stripping tests showed an improved CO tolerance of the Pt/GNs/TiO2. Moreover, the mass activity of the Pt/GNs/TiO2 was further enhanced under light irradiation, with the mass activity of 4715 mA mg(Pt)(-1), which was 1.4 times higher than that of in dark. This work provides new opportunities for exploiting efficient visible photo-assisted electro-catalytic methanol oxidation.