Highly Selective Conversion of Carbon Dioxide to Methanol through a Cu-ZnO-Al2O3-ZrO2/Cu-MOR Tandem Catalyst

Methanol formation from CO2 hydrogenation attracts great attention in view of utilization of carbon resources. However, CO2 transformation to methanol is challenging because of the thermodynamic equilibrium restriction and water-caused catalyst deactivation. It is desired, therefore, to develop highly active, selective and stable catalysts for CO2 hydrogenation to methanol. Herein, we propose a novel tandem catalyst composed of Cu-ZnO-Al2O3-ZrO2 (CZAZ) and Cu-MOR for highly selective conversion of CO2 to methanol. During CO2 hydrogenation by the CZAZ catalyst, the by-product methane is continuously transformed to methanol through reaction with water via the Cu-MOR catalyst, thus enhancing CO2 conversion and methanol selectivity. Under mild reaction conditions (200 & DEG;C and 3.0 MPa), high CO2 conversion (40.7 %) and methanol selectivity (97.6 %) are achieved, outperforming state-of-the-art CO2 hydrogenation catalysts. Further, water-caused deactivation of the catalyst through aggregation and densification is suppressed owing to water consumption via methane oxidation to methanol, validating a high CZAZ/Cu-MOR tandem catalyst stability.

Automated summary

The formation of methanol from CO2 hydrogenation is a topic of great interest in terms of carbon resource utilization. However, this transformation is challenging due to thermodynamic equilibrium restriction and water-caused catalyst deactivation. Therefore, the development of highly active, selective, and stable catalysts for CO2 hydrogenation to methanol is highly desired. In this study, a novel tandem catalyst composed of CZAZ and Cu-MOR is proposed, which achieves highly selective conversion of CO2 to methanol. The by-product methane is continuously transformed to methanol through reaction with water, enhancing CO2 conversion and methanol selectivity. High CO2 conversion (40.7%) and methanol selectivity (97.6%) are achieved under mild reaction conditions, outperforming state-of-the-art CO2 hydrogenation catalysts. Furthermore, the water-caused deactivation of the catalyst is suppressed, validating a high stability of the CZAZ/Cu-MOR tandem catalyst.