Cost-effective and dynamic carbon dioxide conversion into methane using a CaTiO 3@Ni-Pt catalyst in a photo-thermal hybrid system

摘要

This research focuses on the synergy of converting carbon dioxide (CO2) into methane (CH4) by simultaneously introducing light and heat as dynamic sources to activate the catalyst. A CaTiO3@Ni-Pt catalyst, loaded with 30.0?wt.% Ni and 1.0?wt.% Pt on a perovskite CaTiO3support was introduced. The photo-thermal catalytic hybrid system has two features that distinguish it from other photo- or thermal-catalytic systems. First, unlike the CO2thermal-methanation reaction where CO2and H2react at a molar ratio of 1:4, 2.0?mol of H2was replaced with 2.0?mol H2O in the photo-thermal catalytic hybrid system compared to the thermal-methanation reaction requiring 4.0?mol of H2. Second, by loading Ni and Pt, which are catalytic active species with excellent CO2and H2adsorption abilities, the CO2reduction (46.48%) was promoted and the CH4selectivity (99.46%) in the product was increased compared to the photo-methanation reaction. The CaTiO3@Ni-Pt not only inhibited the recombination of the photo-generated charges, but also facilitated the adsorption of the reactants in the photo-thermal hybrid system. The quantum efficiency of the CaTiO3@Ni-Pt catalyst measured for the photo-thermal hybrid system steadily increased to 180?°C. Nevertheless, this study implies that a photo-thermal hybrid system can be useful to photo-reducing CO2by adding a small amount of heat. From a thermal reaction standpoint, a photo-thermal hybrid system can be used to reduce the reaction temperature during CO2thermal-methanation and to reduce the consumption of H2in half.