High-performance CuMgAl catalysts derived from hydrotalcite for CO2 hydrogenation to methanol: Effects of Cu-MgO interaction

Using the coprecipitation approach, the CuMgAl catalysts with varying Cu loadings (x-CMA, x = 4, 6, 8, 10, 12 wt.%) were created from hydrotalcite precursors and used in the CO2 hydrogenation to methanol process. In this work, XRD, N2 adsorption-desorption, TEM, H2-TPR, CO2-TPD, H2-TPD, XPS, and in situ DRIFTS characterization techniques were used to examine the structure and surface characteristics of x-CMA catalysts. The results demonstrated that an appropriate interaction between Cu and MgO was formed when the Cu loading was 10 wt%, which was conducive to the generation of more Cu-MgO interfaces, boosting the adsorption of CO2. The appropriate interaction between Cu and MgO also facilitates the production of Cu0, enhancing the dissociation of H2. The conversion of CO3 * and HCO3 * to HCOO * has been sped up by advancements in CO2 adsorption and H2 dissociation, which made the subsequent conversion to CH3OH easier. It also be found that 10-CMA obtained by the coprecipitation approach exhibited more Cu-MgO interfaces than 10-C/MA prepared by the impregnation method. At 2.5 MPa and 240 °C, the 10-CMA catalyst had the maximum STYCH3OH of 408.6 g⋅kgcat.−1⋅h−1 with the XCO2 of 14.1 % and SCH3OH of 93.9 %. The findings presented in this work may offer a fresh perspective on how to create high-efficiency catalysts that hydrogenate CO2 into methanol.