Breaking the activity-durability trade-off in platinum electrocatalysts for hydrogen evolution through twin boundary...

Platinum (Pt) electrocatalysts face a trade-off between catalytic activity and durability in the hydrogen evolution reaction (HER). Designing Pt with a predominantly exposed (1 1 1) facet while improving its intrinsic activity remains a challenging endeavor. In this study, we synthesize high-entropy alloy (HEA) catalysts containing PtPdAuCuCo, featuring tunable (1 1 1)/(1 1 1) twin boundaries (TBs) achieved by entropy modulation. The incorporation of TBs creates favorable convex sites that facilitates overpotentially deposited hydrogen, leading to fast HER kinetics. Density functional theory (DFT) calculations indicate that the presence of TBs strengthens the H adsorption due to enhanced electron transfer from the metal to the adsorbate, an effect not observed in TB-free HEAs with even greater Pt contents. Moreover, the HEA with TBs shows an upshifted d band center and increased bonding state occupancy compared to its TB-free counterpart. Consequently, it exhibits exceptional HER performance, achieving outstanding stability for 15 days without degradation and ultralow overpotentials of 51 and 72 mV at 10 and 100 mA cm^-2, respectively, outperforming TB-free HEAs. The mass activity reaches 3.05 A mg^-1_Pt at 100 mV, exceeding that for TB-free HEA by 23.5 folds. Our findings highlight the potential of TB-engineering to optimize the activity-durability trade-off in Pt electrocatalysts.