Efficient activation of Co/SBA-15 catalyst by high-frequency AC-DBD plasma thermal effect for toluene removal

Abstract

Dielectric barrier discharge (DBD) plasma excited by high-frequency alternating-current (AC) power supply is widely employed for the degradation of volatile organic compounds (VOCs). However, the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency. In this work, an innovative DBD thermal-conducted catalysis (DBD-TCC) system, integrating high-frequency AC-DBD plasma and its generated thermal effect to activate the Co/SBA-15 catalyst, was employed for toluene removal. Specifically, Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 kV. At 12.4 kV, the temperature in the catalyst zone could reach 261 °C in the DBD-TCC system, resulting in an increase in toluene degradation efficiency of 17%, CO2 selectivity of 21.2%, and energy efficiency of 27%, respectively, compared to the DBD system alone. In contrast, the DBD thermal-unconducted catalysis (DBD-TUC) system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation, highlighting the crucial role of AC-DBD generated heat in activating the catalyst. Furthermore, the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized. This work is expected to provide an energy-efficiency approach for high-frequency AC-DBD plasma removal of VOCs.