Selection Mechanism of Synergistic Effect between Dielectric Barrier Discharge Plasma and Cu/Γ-Al2o3 Catalyst in Carbonyl-Sulfide Conversion: Electric Field Changes Energy Barrier and Reaction Path

Abstract

Dielectric barrier discharge (DBD) synergistic catalysis technology combines the high reaction activity of a plasma and the high reaction selectivity of a catalyst and has attracted increased attention in recent years. In this work, the conversion of carbonyl sulfide (COS) by DBD combined with a Cu/γ-Al 2 O 3 catalyst was studied and compared with the conversion of COS with thermocatalysis and DBD alone. The removal efficiency of COS reached to 98.9% at 16 kV and there was no gaseous sulfur byproduct (H 2 S and SO 2 ) generated at the first 4 hours. The catalysts were characterized by Brunauer–Emmett–Teller analysis, X-ray diffractometry, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray fluorescence spectrometry. A fiberoptic spectrometer was used to capture the spectrum during the reaction, and Gaussian software was used to simulate and calculate the reaction barrier of the reaction path by considering the electric field. Cu on the Cu/γ-Al 2 O 3 catalyst converted to Cu 2 S and CuS when it reacted with COS, and a cycle reaction with a low energy barrier between Cu 2 S, CuS, and COS was built when treated with DBD and Cu/γ-Al 2 O 3 . These key reasons indicate why COS conversion showed perfect product selection and a low energy consumption when treated with Cu/γ-Al 2 O 3 in DBD plasma.

Keywords: Carbonyl sulfide, Cu/γ-Al2O3 catalyst, Dielectric barrier discharge, Plasma-catalysis, Gaussian