Solvent isotope effect on reduction of H2O or CO2 with glycerine under alkaline hydrothermal condition

The solvent isotope effect was investigated with 1H- and 2H-NMR, LC-MS and GC-MS analyses on the reduction of H2O or CO2 with glycerine under alkaline hydrothermal conditions. The solvent isotope study results show that the H on the β-C of lactate is almost exchanged by D2O, which suggests that the hydroxyl (-OH) group on the 2-C of glycerine is first transformed into a carbonyl (C=O) group and then is converted back into a -OH group to form lactate; a large amount of D is found in the produced hydrogen gas or formic acid, which shows that the water molecules act as a reactant; and D% in the produced hydrogen gas or formic acid is far more than 50%, which straight-forwardly shows that acetol is formed in the first place as the most probable intermediate by undergoing a dehydration reaction rather than a dehydrogenation reaction. ©, 2015, Science Press. All right reserved.