Artificial photosynthesis, specifically H2O dissociation for CO2 reduction with solar energy, is regarded as one of the most promising methods for sustainable energy and utilisation of environmental resources. However, a highly efficient conversion still remains extremely challenging. The hydrogenation of CO2 is regarded as the most commercially feasible method, but this method requires either exotic catalysts or high-purity hydrogen and hydrogen storage, which are regarded as an energy-intensive process. Here we report a highly efficient method of H2O dissociation for reducing CO2 into chemicals with Zn powder that produces formic acid with a high yield of approximately 80%, and this reaction is revealed for the first time as an autocatalytic process in which an active intermediate, ZnH− complex, serves as the active hydrogen. The proposed process can assist in developing a new concept for improving artificial photosynthetic efficiency by coupling geochemistry, specifically the metal-based reduction of H2O and CO2, with solar-driven thermochemistry for reducing metal oxide into metal.

We report a highly efficient water splitting for CO2 reduction into formic acid with a commercially available metal of Fe powder without adding any other catalyst. An excellent formic acid yield of more than 90% was attained.

The synthesis of triazoles via the three-component coupling reaction of unactivated terminal alkynes, allyl carbonate, and trimethylsiyl azide under the Pd(0)-Cu(I) bimetallic catalyst is developed. The reaction most probably proceeds through the formation of a pi-allylpalladium azide complex and a copper-acetylide followed by a successive [3 + 2] cycloaddition. The deallylation of the resulting allyltriazoles proceeds very easily by the Ru-catalyzed isomerization followed by the ozonolysis of the resulting propenyltriazoles to give the triazoles in high yields.

A one-pot hydrothermal conversion of cellulose with CuO as an oxidant was investigated under alkaline conditions. The results showed that a high yield of organic acids, mainly including acetic acid, glycolic acid, lactic acid, and formic acid, was obtained from cellulose. The highest total yield of the four organic acids reached 43.0% at 325 °C for 1 min. CuO can effectively increase the total yield of organic acids, and Cu 2 O and Cu 0 can be produced from the proposed process. A reaction pathway of cellulose conversion into organic acids in the presence of CuO was investigated and proposed. The present study is expected to be a link in the development of a new and green method of both cellulose conversion and CuO smelting.

A novel approach for the production of 2,5-hexanedione (HDN) and 3-methyl-2-cyclopenten-1-one (3-MCO) from 5-hydroxymethylfurfural (HMF) by water splitting with Zn is reported for the first time.