Improved CO tolerance of Pt nanoparticles on polyaniline-modified carbon for PEMFC anode

•Polyaniline-modified carbon-supported Pt catalysts are synthesized by a traditional impregnation method.•The optimum polyaniline content in Pt/C-PANI is determined to be 5%.•The Pt/C-PANI-5 catalyst exhibits significantly improved CO tolerance compared to Pt/C and commercial PtRu/C.•This work presents a potential solution for developing low-cost, CO-tolerant fuel cell catalysts. The anode Pt catalyst of a proton-exchange membrane fuel cell (PEMFC) is susceptible to poisoning by trace amounts of CO in hydrogen, which restricts its large-scale commercialisation. Therefore, developing PEMFC catalysts with CO tolerance is crucial as it would reduce the requirement for hydrogen purity. In this study, we present a CO-tolerant catalyst for the PEMFC anode synthesised by loading Pt onto a polyaniline-modified conductive carbon composite support (Pt/C-PANI). The results showed that the catalyst containing 5% PANI in the composite support (Pt/C-PANI-5) exhibited optimal hydrogen oxidation reaction activity and CO tolerance. Electrochemical tests showed that the current drop of Pt/C-PANI-5 was 6.8%, compared to 20% and 12% for Pt/C-sys and commercial PtRu/C catalysts, respectively. Furthermore, results of the single-cell test confirmed improved CO tolerance. These findings provide a potential solution for developing cost-effective fuel cell catalysts with improved CO tolerance.