Synergistic Modulation of Multiple Sites Boosts Anti‐Poisoning Hydrogen Electrooxidation Reaction with Ultrasmall (Pt0.9Rh0.1)3V Ternary Intermetallic Nanoparticles

Abstract Promoting the hydrogen oxidation reaction (HOR) activity and poisoning tolerance of electrocatalysts is crucial for the large‐scale application of hydrogen‐oxygen fuel cell. However, it is severely hindered by the scaling relations among different intermediates. Herein, lattice‐contracted Pt−Rh in ultrasmall ternary L1 2 ‐(Pt 0.9 Rh 0.1 ) 3 V intermetallic nanoparticles (~2.2 nm) were fabricated to promote the HOR performances through an oxides self‐confined growth strategy. The prepared (Pt 0.9 Rh 0.1 ) 3 V displayed 5.5/3.7 times promotion in HOR mass/specific activity than Pt/C in pure H 2 and dramatically limited activity attenuation in 1000 ppm CO/H 2 mixture. In situ Raman spectra tracked the superior anti‐CO* capability as a result of compressive strained Pt, and the adsorption of oxygen‐containing species was promoted due to the dual‐functional effect. Further assisted by density functional theory calculations, both the adsorption of H* and CO* on (Pt 0.9 Rh 0.1 ) 3 V were reduced compared with that of Pt due to lattice contraction, while the adsorption of OH* was enhanced by introducing oxyphilic Rh sites. This work provides an effective tactic to stimulate the electrocatalytic performances by optimizing the adsorption of different intermediates severally.