Effect of Ni content on Cu-Mn/ZrO2 catalysts for methanol synthesis from CO2 hydrogenation

The synthesis of methanol via CO2 hydrogenation is a promising route to a carbon-neutral economy. The key to the process is catalysts. In this research, a series of Cu-Mn-Ni/ZrO2 catalysts with different Ni : Cu ratios (CMZ, CMNZ-0.01, CMNZ-0.05, CMNZ-0.1, and CMNZ-0.2) were synthesized by co-precipitation for the hydrogenation of CO2 to methanol. It was found that an appropriate Ni content led to increased Cu dispersion and surface area. Consequently, more active Cu sites were exposed, leading to higher CO2 conversion. Moreover, the addition of a small amount of Ni enhanced the basicity on the catalyst surface, effectively stabilizing intermediates such as *COOH and *OCH3, which improved the methanol selectivity. At 240 degrees C and 5 MPa, the CMNZ-0.01 catalyst showed better performance with a methanol selectivity of 57.84% and CO2 conversion of 14.57%, which were higher than those of the Cu-Mn/ZrO2 catalyst.