Exploring transition metal (Cr, Mn, Fe, Co, Ni) promoted copper-catalyst for carbon dioxide hydrogenation to methanol

Abstract

Methanol production from direct CO2 hydrogenation has been widely envisaged to have key role in promoting CO2 utilization. The approach is a serious option in alleviating global warming, thus, contributing to sustainable development. However, the efficiency of methanol production from direct CO2 hydrogenation is highly dependent on the reactivity of catalyst. In this study, the structure-activity relationships of transition metal (Cr, Mn, Fe, Co, Ni) promoted copper-catalyst in direct CO2 hydrogenation to methanol were established by a systematic comparison between the synthesized catalysts. The copper-catalyst used in the study was Cu/ZnO/SBA-15 (CZ/SBA-15). Catalytic performance of all the synthesized catalysts was evaluated in a continuous-flow fixed-bed micro-reactor under kinetic-controlled conditions. Overall, the manganese promoted copper-catalyst (Mn-CZ/SBA-15) was determined as the most active catalyst. The outstanding performance of Mn-CZ/SBA-15 was due to the jointly presence of small copper crystallites and strong interaction between copper oxide and other oxide species in the catalyst. At reaction temperature of 180°C, under reaction pressure of 4.0 MPa, WHSV of 60 L/gcat.h, and H2:CO2 mole ratio of 3:1, the catalyst presented the highest methanol yield of 10.4%. The CO2 conversion achieved was 10.5% and the methanol selectivity was 98.6%.Methanol production from direct CO2 hydrogenation has been widely envisaged to have key role in promoting CO2 utilization. The approach is a serious option in alleviating global warming, thus, contributing to sustainable development. However, the efficiency of methanol production from direct CO2 hydrogenation is highly dependent on the reactivity of catalyst. In this study, the structure-activity relationships of transition metal (Cr, Mn, Fe, Co, Ni) promoted copper-catalyst in direct CO2 hydrogenation to methanol were established by a systematic comparison between the synthesized catalysts. The copper-catalyst used in the study was Cu/ZnO/SBA-15 (CZ/SBA-15). Catalytic performance of all the synthesized catalysts was evaluated in a continuous-flow fixed-bed micro-reactor under kinetic-controlled conditions. Overall, the manganese promoted copper-catalyst (Mn-CZ/SBA-15) was determined as the most active catalyst. The outstanding performance of Mn-CZ/SBA-15 was due to the jointly presence of small copper cr...