Role of the Structure and Morphology of Zirconia in Zno/Zro2 Catalyst for Co2 Hydrogenation to Methanol

Abstract

The global CO2 emission problem is getting increasingly severe nowadays. Hence a suitable CO2 hydrogenation technology to obtain methanol is an efficient way to achieve carbon neutrality. ZnO nanoparticles were loaded on ZrO2 with different morphologies via the impregnation method. This was followed by the investigation of the effect of zirconia structure and morphology on the interfacial synergy manifested in the catalysts and the catalytic performance in CO2 hydrogenation. The results showed that the CO2 conversion of the ZnO/ZrO2-F catalyst possessing a hollow nanoframe-like morphology was significantly enhanced, exhibiting the highest methanol space-time yield, which was 1.78 times higher than that of the ZnO/ZrO2-P catalyst which has an aggregate shape of irregular particles. The unique morphology effectively inhibits the transition of the metastable phase t-ZrO2 to the m-ZrO2 phase while forming a special interfacial structure with the loaded ZnO to enhance the three-phase interfacial synergy. This enhances the hydrogen activation capacity and generates more oxygen vacancies favorable to the activation of CO2.

Keywords: Morphology effect, Zirconia support, Oxygen vacancy, CO2 hydrogenation, Methanol synthesis