Atomically dispersed tungsten enhances CO tolerance in electrocatalytic hydrogen oxidation by regulating the 5d-orbital electrons of platinum

The susceptibility of Pt catalyst surfaces to carbon monoxide (CO) poisoning in anodic hydrogen oxidation reaction (HOR) has been a critical constraint on the development of proton exchange membrane fuel cells (PEMFCs). Effectively regulating the electronic structure of Pt to enhance CO resistance is crucial for developing high-performance catalysts with robust anti-poisoning capabilities. Herein, the Pt/W@NCNF featured by Pt nanoparticles and atomical dispersed tungsten (W) sites on N-doped carbon nanofibers is developed for CO tolerance HOR catalyst. The presence of W enables the electron transfer from Pt, which promotes electron rearrangement in the Pt-5d orbitals. It not only optimizes the adsorption of H∗ and CO∗ on Pt, but also the OH∗ intermediates adsorbed on the W sites oxidize the CO∗ adsorbed on Pt, thereby retaining more active sites for H 2 adsorption and oxidation. The HOR exchange current density of Pt/W@NCNF reaches 1.35 times that of commercial Pt/C, and the limiting current density decreases by only 3.4% after introducing 1000 ​ppm CO in H 2 . Notably, the Pt/W@NCNF-based PEMFCs deliver markedly superior performance across a range of CO concentrations. The present study demonstrates that electronic modulation of Pt is an effective strategy for simultaneously achieving resistance to CO and promoted HOR activity. Utilizing atomically dispersed W sites to modulate the electronic structure of Pt can optimize the adsorption kinetics of hydrogen and CO, thereby promoting hydrogen oxidation activity and hydrogen-oxygen fuel cell performance even in H 2 /CO mixture containing 1000 ​ppm CO. • The Pt/W@NCNF featuring Pt nanoparticles and atomically dispersed W sites has been designed as a CO-tolerant HOR catalyst. • Incorporating atomically dispersed W sites modulates Pt-5d orbital electronic structure to optimize H 2 ​and CO adsorption. • It shows superior HOR activity and stability at H 2 /1000 ppm CO and enhanced PEMFC performance across various CO levels.