CO ₂ conversion in a dielectric barrier discharge plasma by argon dilution over MgO/HKUST-1 catalyst using response surface methodology

Abstract

Metal-organic frameworks (MOFs) as carbon dioxide adsorption in combination with metal oxides have shown catalyst application in CO ₂ conversion. Herein, the MgO/HKUST-1 catalyst is synthesized to direct conversion of CO ₂ upon dilution by argon in a cylindrical dielectric barrier discharge (DBD) reactor. A water-cooling circulation adjusts the reactor temperature, and aluminum powder is used as a high-voltage electrode. The effect of the discharge power, feed flow rate, CO ₂ fraction, and their interaction in plasma and plasma catalyst method on CO ₂ conversion (R ₁), effective CO ₂ conversion (R ₂), and energy efficiency (R ₃) is evaluated by central composite design (CCD) based on response surface methodology. The Analysis of Variance (ANOVA) results demonstrate that the quadratic regression model describes CO ₂ conversion and effective CO ₂ conversion, and the reduced cubic model describes energy efficiency. The results indicate that the method (plasma, plasma catalyst) and discharge power on R ₁ and R ₂ have a considerable effect. Also, the method and CO ₂ fraction on R ₃ have the greatest impact, respectively. In the plasma and plasma catalyst method maximum CO ₂ conversion is 12.3% and 20.5% at a feed flow rate of 80 ml/min, CO ₂ fraction of 50%, and discharge power of 74 W.