LAUSR

Abstract Developing CO-tolerant electrocatalysts is of great importance for the practical use of proton exchange membrane fuel cells (PEMFCs) fed with reforming hydrogen. Transitional metal oxides are a class of promising component to (i) alleviate the CO adsorption on Pt and (ii) provide as a stabilized support for Pt nanoparticles. Herein, we developed an electrostatic assembly strategy to deposit Pt nanoparticles uniformly on the hexagonal tungsten oxides (hex-WO3) modified by polyethleneimine (PEI). It is the first time employing hex-WO3 with biomimetic proton channels and mixed ionic electronic conductivity as supports in PEMFCs. Also, this work is the first report using PEI as a linker to assemble Pt nanoparticles and metal oxide supports. The Pt/PEI-hex-WO3 composites possess excellent dispersion of Pt nanoparticles with average size less than 3 nm even at Pt loadings as high as 40 wt%. The Pt/PEI-hex-WO3 catalysts exhibit superior catalytic activity and electrochemical stability for the hydrogen electro-oxidation (HOR) in the presence of CO, and good PEMFC performance compared to the conventional carbon-supported Pt catalysts, attributed to the bifunctional mechanism and a strong metal-support interaction (SMSI).