EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The increased concentration of carbon dioxide in the environment poses a great threat to human health and environmental safety, thus, CO2 utilization is of crucial importance nowadays. Noble metals especially in the nanoscale have proved to show excellent catalytic properties in many important processes. However, they are expensive materials which amount is limited, hence, search for new solutions is of great interest. Using supported noble metals catalysts is a promising approach, resulting in good activity while remaining more economically feasible.
Implementation of mesoporous metal oxides with adequate porosity as supports can greatly enhance surface activity in CO2 methanation. In noble metal-metal oxide catalytic systems metal oxides not only aid for the dispersion of noble metals but also affect catalytic activities and selectivity due to the presence of strong metal-support interaction. The nature of this interaction is not trivial and influenced by many factors such as support electronic structure, support surface area, basicity, reducibility, morphology.
In this work, we fabricated different types of mesoporous oxide skeletons (Co3O4, and MnO2) through replica method using mesoporous KIT-6 as a hard template and nitrate salts of the transition metals as precursors. Mesoporous Co3O4 (m-Co3O4) was almost exclusively methane selective while over m-MnO2 the carbon monoxide was detected as the main product. Different techniques such as HRTEM, XRD, NAP XPS, DRIFTS, Raman Spectroscopy, EXAFS, and CO2-TPD were utilized to identify which properties of mesoporous metal oxides are responsible for the observed activity. We also have made an attempt to enhance the catalytic activity of the catalysts in question by drop-casting 1% 5nm Pt nanoparticles and applied the abovementioned techniques to analyze the noble metal loading effect.