Homogeneous catalysts for CO2 hydrogenation to methanol and methanol dehydrogenation to hydrogen generation

The consumption of fossil fuels has increased CO2 emissions. Therefore, methods for effectively reducing CO2 emissions have been actively developed. In addition, as fossil fuels are a limited resource, it is necessary to find an alternative carbon source. Methanol is a promising chemical raw material and fuel for internal combustion engines and fuel cells. CO2 can be used as a raw material that reacts with hydrogen to synthesize methanol, which is expected to lead to a reduction in atmospheric CO2 concentration. In recent years, the discovery of catalysts that generate hydrogen via the dehydrogenation of methanol has allowed the combination of methanol synthesis and dehydrogenation for facilitating efficient chemical hydrogen storage. In this paper, we summarize the homogeneous catalysts that demonstrate catalytic activity in methanol synthesis via CO2 hydrogenation and the generation of hydrogen via methanol dehydrogenation.