Characteristics and catalytic properties of copper on MCF-SI and SBA-15 for hydrogenation of carbon dioxide

Abstract

At present, the production of methanol from the hydrogenation of carbon dioxide is widespread. The current popular catalysts include copper oxide, zinc oxide and aluminum oxide (CZA) catalysts. As the reaction progresses, the catalyst forms coke. This causes the efficiency of the catalyst to decrease. In this study, the copper catalyst on the mesoporus silica support was investigated. This type of support has high thermal stability. Cu catalysts were synthesized on MCF-Si and SBA-15 supports with different pore morphology such as spherical and hexagonal shape, respectively, by wetness impregnation (W) method and incipient wetness impregnation (IW) with a copper loading of 60 wt%. The synthesized catalysts were then subjected to physical and chemical characterization by SEM-EDX, XRF, XRD, TEM, N2 physisorption, TGA, CO-chemisorption and H2-TPR. It was found that metal impregnation of the support in both methods did not change the structural characteristics. Before taking the catalyst to hydrogenation with CO2 and H2, the reaction is divided into 2 parts: the first part was tested at a temperature range of 100-400°C under pressure of 10 bar, to study the optimum temperature for each catalyst. The Cu catalyst supported on MCF-Si had the highest ratio of methanol at 300 °C. However, the catalyst supported by SBA-15 had the highest selectivity of methanol at 400 °C. In the second part, the catalyst was then tested at 400 °C under pressure of 10 bar for 5 hours (time on stream) for further study of catalyst deactivation. It revealed that all synthesized catalysts produced very little methanol as compared to carbon monoxide. Therefore, it is more suitable for use in reverse water-gas shift (RWGS) reaction.