Abstract
In recent years, global warming issues due to the increase in carbon dioxide (CO2) concentration triggered by use of fossil fuels have become even more serious. Therefore, methanation of CO2 has been considered, e.g. by Sabatier reaction. This reaction requires catalysts such as Ni, and development of catalysts capable of producing methane with high efficiency is required. In our previous studies, it has been reported that methanation is possible by ball-milling of LaNi5 under CO2 + H2 atmosphere. Furthermore, ball-milling resulted in a complex structure of Ni / La oxide and carbonates on a nanoscale, suggesting high catalytic activity at the metal/oxide interface. This suggests that ball-milling is effective in catalyst production. In this study, we attempted to prepare a composite powder in which Ni is supported on CaO, which is an inexpensive and easily-reacting oxide with CO2, and investigated its potential as a CO2 methanation catalyst. Our results revealed that the methanation of CO2 occurs with using Ni/CaO composite, while even higher catalytic activity was observed in case of Ni/CaCO3 composite.
