Product Selectivity Controlled by the Nano-Environment of Ru/Zsm-5 Catalysts in Non-Thermal Plasma Catalytic Co2 Hydrogenation

Abstract

Herein, Ru nanoparticles (NPs) on ZSM-5 zeolites with different morphologies and Ru NPs locations obtained by different preparation methods were investigated  using plasma-catalytic CO2 hydrogenation. The results revealed that the performance of the plasma-catalysis depends on the structure of the catalysts. Specifically, ZSM-5 nanocrystal/nanosheet promoted the formation of small and highly dispersed Ru NPs (of 9–15 nm), which showed the strong interaction with CO  and promoted the selective CO2 conversion to CH4. Regarding the location of the Ru NPs, the accessibility of Ru NPs to the plasma-induced energetic species was rather important at lower input energies. Conversely, at higher input plasma energies, the intrinsic property of the Ru NPs determines the catalytic performance, and thus the 1%Ru(in) catalyst containing internally encapsulated Ru showed high CO2 conversion of ~93% and CH4 selectivity of ~85%, respectively. Importantly, higher input energies led to the formation of C2H6 via gas phase CH4 coupling reactions.

Keywords: Non-thermal plasma (NTP), catalysis, CO2 hydrogenation, Ru nanoparticles (NPs), ZSM-5