Kinetics and mechanism of reduction of CO₂ by glycerol under alkaline hydrothermal conditions

The increasing greenhouse gas emission strongly requires new efficient methods to close the carbon cycle. One promising strategy is to achieve reduction of CO₂ and utilization of glycerol simultaneously in one-pot hydrothermal reaction. A possible mechanism through hydrogen-transfer reduction from glycerol was proposed by previous researchers. However, the detailed mechanism is still not clear, which prohibits the development of catalyst. In this study, by adopting a joint experimental and theoretical method, a kinetic model comprising reduction of CO₂ and glycerol conversion is elucidated. The activation energy values are obtained in experimental and theory, respectively. The reduced species was found to be CO₂ not bicarbonate based on the theoretical calculation.