A comparative study of tungsten-modified PtRu electrocatalysts for methanol oxidation

• Tungsten compounds were used to modify PtRu catalysts for methanol electro-oxidation.
• Relationship between W species and the performance of W-modified PtRu/C was studied.
• High activity of PtRuWOx/C was ascribed to the hypo–hyper-d–d-bonding.
• Good poison resistance of PtRuPW12/C was attributed to the protective PW12 layer.

The carbon supported PtRu nanocatalyst is modified by two kinds of tungsten compounds, i.e., tungsten oxide (WOx) and phosphotungstic acid (H3PW12O40, PW12), respectively, and the catalytic performances of the modified catalysts for methanol oxidation are evaluated. The results show that tungsten oxide and phosphotungstic acid exhibit different promoting effects on the catalytic performance of the PtRu nanocatalyst for methanol oxidation. The WOx-modified PtRu nanocatalyst has a considerably high catalytic activity, which is attributed to the uniform distribution of PtRu nanoparticles on the carbon support and the strong metal-support interaction (SMSI) between the hypo-d-tungsten and the hyper-d-platinum. The PW12-modified PtRu nanocatalyst has a good poison resistance, which is ascribed to the protective effect of the self-assembled PW12 layer on the catalyst surface.