In Situ Modification of CuO–Fe(2)O(3) by Nonthermal Plasma: Insights into the CO(2)-to-CH(3)OH Hydrogenation Reaction

[Image: see text] The hydrogenation of CO(2) to CH(3)OH on the binary mixed metal oxides of CuO–Fe(2)O(3) under nonthermal plasma discharge has been reported in this study. The catalysts are synthesized using the sol–gel route and characterized by XRD, FTIR, SEM, and XPS techniques. The impact of CuO mixing with Fe(2)O(3) on CO(2) conversion and CH(3)OH yield has been investigated. Herein, we have compared two distinct techniques, namely thermal and plasma catalytic processes. The overall outcome shows that the CO(2) conversion and CH(3)OH production increase with an increase in CuO mixing with Fe(2)O(3). The synthesized catalyst does not show significant CO(2) conversion and CH(3)OH formation in the thermal catalytic process (100–250 °C). Interestingly, when plasma discharge is combined with thermal heating, CO(2) conversion and CH(3)OH production significantly improve. The plasma discharges in the CO(2)/H(2) gas stream, at low temperatures (<200 °C), reduce Cu(+2) to Cu(+1) and Fe(+3) to Fe(+2), which could probably enhance the CO(2) conversion and CH(3)OH production. Among the catalysts prepared, 15% CuO–Fe(2)O(3) exhibited the best catalytic activity with 13.2% CO(2) conversion, 7.3% CH(3)OH yield, and a space–time yield of 13 mmol(CH3OH)/h g(cat), with 4.67 kJ/L of specific input energy (SIE). The CH(3)OH space–time yield is 2.9-fold higher than that of the commercial catalyst Cu/ZnO/Al(2)O(3), which is operated at 30 °C with 45.45 kJ/L SIE.