Tuning the Pt-N coordination in Pt/MOFs nanosheets under N2 plasma for enhanced oxygen reduction reaction

Regulation of the local coordination of metal sites can tune the electronic structure of catalysts, thereby improving electrocatalytic activity and reaction selectivity. This study proposes a strategy for designing highly active catalysts by regulating Pt-N coordination through N2 plasma treatment. Zn-BDC (1,4-benzenedicarboxylic acid) nanosheets embedded with Pt nanoparticles (Pt/Zn-BDC) were successfully fabricated. Subsequently, radio frequency (RF) discharge N2 plasma was applied to tune the Pt sites of Pt/Zn-BDC at room temperature. The plasma-treated Pt/Zn-BDC showed enhanced catalytic activity for the oxygen reduction reaction (ORR) with a high half-wave potential (0.835 V), superior to those of pristine Pt/Zn-BDC and 20 wt% Pt/C. Notably, rechargeable Zn-air batteries based on plasma-treated catalysts were demonstrated to exhibit high efficiency and stability. The enhanced catalytic performance originated from the optimized coordination environment and electronic structure of the Pt sites under N2 plasma treatment. This study provides a facile, green method of regulating promising ORR electrocatalysts via low-temperature plasma treatment.