Cold-plasma technique enabled supported Pt single atoms with tunable coordination for hydrogen evolution reaction

Coordination tunability of the single-atom catalysts (SACs) is an essential but challenging issue for the catalyst sifting and structure-activity relationship analysis. Herein, Pt single atoms with tunable coordination are readily achieved via a facile cold-plasma technique by changing the gas type (N-2, Ar, or Air) and treatment duration. Combining with density functional theory calculation, the Pt-N coordination concentration is predicted to be highly correlated with adsorption free energy of H* atoms (Delta G(H*)) for the hydrogen evolution reaction (HER), which is further validated experimentally. Remarkably, the sample with N, O co-dopant introduced by air plasma exhibits a high TOF of similar to 13 H-2 s(-1) at 40 mV, and outstanding mass activity of 7.41 A mg(Pt)(-1) for HER, which is 26.5 times of commercial Pt/C catalyst. The enhanced performance might originate from the optimized electronic structure of active carbon site with moderate electron transfer and p-band center, which enables a suitable binding strength with H* and thus a near-zero Delta G(H*).

Automated summary

The study demonstrates the tunability of Pt single atoms coordination through a cold-plasma technique and predicts a strong correlation between Pt-N coordination concentration and adsorption free energy of H* atoms for the hydrogen evolution reaction (HER). The sample with N, O co-dopant introduced by air plasma shows significantly enhanced performance, with a high turnover frequency and outstanding mass activity, suggesting that the optimized electronic structure of active carbon site plays a key role in improving the catalyst's efficiency.