(173r) Unveiling the Surface Kinetics of DMF Modified Pt-Based ORR Catalysts By Molecular Dynamics Simulations

As an essential of prosperity of fuel cells, high activity and long-term stability are always the goal of Platinum (Pt)-based oxygen reduction reaction (ORR) catalysts. The catalyst-electrolyte interfacial properties that can greatly affect the micro-kinetics such as physisorption/desorption have not been sufficiently explored. Herein, by using molecular dynamics (MD) simulations, we found dimethylformamide (DMF) surface modification can enable increased interfacial O₂ concentration, longer O₂ physisorption time by disrupting the interfacial H₂O network, which boosts the reaction kinetics by a factor of 2. Such interfacial regulation strategy is universal to a couple of Pt-based catalysts. An optimal DMF-modified PtCuNi catalyst delivers an unprecedented specific activity of 21.8 ± 2.1 mA/cm^-2 (at 0.9 V vs. RHE), nearly double the previous record, resulting in an ultra-high mass activity of 10.7 ± 1.1 (A/mg_Pt). In addition, the lifetime of catalysts is also considerably extended due to DMF modification.