Pathways and Kinetics for Autocatalytic Reduction of CO<sub>2</sub> into Formic Acid with Fe under Hydrothermal Conditions
Binbin Jin, Ligang Luo, Longfei Xie
Abstract
High Resolution Image Download MS PowerPoint Slide The utilization of CO 2, as a cheap and abundant carbon source to produce useful chemicals or fuels, has been regarded as one of the promising ways to reduce CO 2 emissions and minimize the green-house effect. Previous studies have demonstrated that CO 2 (or HCO 3 – ) can be efficiently reduced to formic acid with metal Fe under hydrothermal conditions without additional hydrogen and any catalyst. However, the pathways and kinetics of the autocatalytic CO 2 reduction remain unknown. In the present work, the reaction kinetics were carefully investigated according to the proposed reaction pathways, and a phenomenological kinetic model was developed for the first time. The results showed that the hydrothermal conversion of HCO 3 – into formic acid with Fe can be expressed as the first-order reaction, and the activation energy of HCO 3 – is 28 kJ/mol under hydrothermal conditions.