Highly-efficient and autocatalytic reduction of NaHCO 3 into formate by in situ hydrogen from water splitting with metal/metal oxide redox cycle

The Earth's sustainable development is threatened by the increasing atmospheric CO2 level which can be attributed to the imbalance of CO2 due to the rapid consumption of fossil fuels caused by human activities and the slow absorption and conversion of CO2 by nature. One of the efficient methods for reconstructing the balance of CO2 should involve the rapid conversion of CO2 into fuels and chemicals. The hydrogenation of CO2 with gaseous hydrogen is currently considered to be the most commercially feasible synthetic route, however, the supply of safe and economical hydrogen sources poses a significant challenge to up-scaling application. Direct utilization of hydrogen from dissociation of water, the most abundant, cheap and clean hydrogen resource, for the reduction of CO2 would be one of the most promising approaches for CO2 utilization. This paper provides an overview of the current advances in research on highly efficient reduction of CO2 or NaHCO3, a representative compound of CO2, into formic acid/formate by in situ hydrogen from water dissociation with a metal/metal oxide redox cycle under mild hydrothermal conditions.