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

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. (paper)