A general strategy for synthesizing bimetallic Pt-based nanoclusters supported on carbon black via non-thermal plasma.

Downsizing Pt-based catalysts to generate a higher surface-to-volume ratio and maximize atom utilization efficiency has been recognized as an effective strategy to achieve high mass activity. However, the synthesis of homogeneous, ultra-small bimetallic nanoclusters remains a significant challenge due to the difficulties in controlling stoichiometry and surface state control, large miscible gaps between different metals and surface state changes induced by the reaction gas environment. In this paper, bimetallic Pt-based nanoclusters such as PtPd, PtRu, PtCu deposited on carbon black (Vulcan XC72R) were fabricated by the reduction of H 2 plasma.The structure and morphology of those prepared catalysts were revealed by HAADF-STEM, HR-TEM, EDS and XPS. The results indicated the prepared Pt-based nanoclusters displayed high dispersibility and small size owning to the non-equilibrium characteristics of non-thermal plasma (NTPs). The average sizes of PtPd, PtRu and PtCu were 2.06 ± 0.68 nm, 3.66 ± 1.34 nm and 1.98 ± 0.7 nm, respectively. Meanwhile, the synthesized PtPd nanoclusters with the ratio of 3:4 exhibited high catalytic activity in the hydrogen evolution reaction (HER). The Pt 3 Pd 4 /VR-P displayed a low overpotential (19 mV) at 10 mA/cm2 and achieved a high mass activity of 5.4 A/mg for HER in 0.5 M H 2 SO 4 solution, which was 13.8 times higher than those of the commercial Pt/C catalysts. Moreover, the Pt 3 Pd 4 /VR-P demonstrated excellent stability with a negatively shifting about 40 mV after 10,000 cycles at a current density of 10 mA/cm2, which was close to that of JM-Pt/C (32 mV). The results prove NTPs technology is effective for the preparation of bimetallic Pt-based nanoclusters. Non-thermal plasma is an innovative method to prepare Pt-based nanoclusters with high dispersibility and small size. The synthesized Pt 3 Pd 4 nanoclusters with an average size of 2.06 ± 0.68 nm displayed a low overpotential (19 mV) at 10 mA/cm2 and achieved a high mass activity of 5.4 A/mg for HER in 0.5 M H 2 SO 4 solution, which was 13.8 times higher than that of the commercial Pt/C catalysts. [Display omitted] • A plasma fabrication technique for synthesis of Pt-based nanoclusters with high dispersibility and small size was developed. • The average sizes of the prepared PtPd, PtRu and PtCu nanoclusters are 2.06 ± 0.68 nm, 3.66 ± 1.34 nm and 1.98 ± 0.7 nm. • The prepared Pt 3 Pd 4 /VR-P exhibits a low overpotential (19 mV) at 10 mA cm−2 and a high mass activity (5.4 A mg−1) for HER. [ABSTRACT FROM AUTHOR]