Enhancement of Adsorption Capacity and Strength for Carbon Dioxide in Gold Nanoparticle-Loaded Zirconia Prepared by Surface Hydrolysis-Deposition Precipitation Method.

From the perspective of protecting the global environment, developing technologies to capture CO2 from emission sources (or the atmosphere) and efficiently convert it into useful substances is an urgent task. Among materials for the carbon capture and utilization, metal oxide-supported Au nanoparticles (Au/MOs) including Au/ZrO2 have attracted considerable attention in recent years. To achieve efficient CO2 conversion, it is essential to control the capacity and strength of CO2 adsorption on the catalyst surface, as well as to have a deep understanding of its adsorption modes. While many papers have been published on the CO2 adsorption properties of ZrO2, we could not find any papers on the effect of supporting Au nanoparticles (NPs) on ZrO2. In this study, the characteristics of Au/ZrO2 prepared by the conventional deposition precipitation (DP) method and a modified DP method for CO2 adsorption were investigated using temperature-programmed CO2 desorption and in situ diffuse reflectance Fourier-transformed infrared spectroscopy. We have shown that surface hydrolysis of ZrO2 significantly enhances the adsorption capacity and strength of CO2 to Au/ZrO2, while specific CO2 adsorbing species can stabilize surface oxygen vacancies around Au NPs.