Understanding the Enhanced Catalytic Desulfurization Mechanism: Gas-Phase and Surface Reactions with a CuCeO_x Catalyst under Nonthermal Plasma Conditions

To understand the mechanisms of enhanced catalytic technologies under nonthermal plasma (NTP) conditions, complex surface processes must be assessed. However, the predictive capability of the Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) processes is limited by various factors. The present study aimed to clarify the interaction mechanisms between NTP and catalysts in the enhancement process, explore the specific pathways of the enhancement process based on E-R and L-H model validations, and obtain data to support the rational design of NTP-enhanced catalytic processes. We investigated CuCeOx catalysts and SO2 removal reaction as a probing reaction using two enhancement scheme configurations, combined with gas-phase reaction process simulations. During the gas-phase reaction stage of the enhancement process, no significant differences were observed among the different configurations caused by the generation of radicals that were induced by N-2 (A(3)Sigma(+)(u))-excited species. However, introducing CuCeOx catalysts altered the enhancement process, and the placement of the catalyst influenced the corresponding desulfurization mechanism.