Plasma-catalytic CO2 hydrogenation to methanol over CuO-MgO/Beta catalyst with high selectivity

Herein, we report a CuO-MgO/Beta catalyst, which exhibits 72.0% methanol selectivity with 8.5% CO2 conversion in plasma-catalytic CO2 hydrogenation at ambient conditions (30 °C and 0.1 MPa). The catalysts have been systematically characterized by XRD, H2-TPR, HRTEM, STEM, XPS, CO2-TPD and NH3-TPD to study the interaction between CuO and MgO, as well as physicochemical properties of the catalysts. Furthermore, in-situ Optical Emission Spectroscopy (OES) and in-situ Fourier Transform Infrared Spectroscopy (FTIR) were employed to investigate the active species in gas-phase and on catalyst surface. The excellent selectivity of the CuO-MgO/Beta catalyst is attributed to synergy between MgO and CuO species. The strong interaction between CuO and MgO leads to electron transfer from MgO to CuO, which is favorable for partially reduction of CuO to form Cu2O active sites. Furthermore, MgO strongly adsorb CO2 to form formate species, which suppresses CO generation and leads to CO2 hydrogenation through Formate pathway for CH3OH production.