甘油水热碱催化还原H2O和CO2的过程

Solvent Isotope Effect on Reduction of H2O or CO2 with Glycerine Under Alkaline Hydrothermal Condition

摘要:

结合氢谱核磁共振（1H NMR）、氘谱核磁共振（2H NMR）、高效液相色谱质谱（LC MS）和气相色谱质谱（GC MS）分析方法，调查了水热碱催化条件下甘油还原水和二氧化碳过程中通过重水（D2O）代替H2O的溶剂同位素效应.研究表明：乳酸分子上β碳的氢完全被替换成氘（D），说明甘油分子上2碳位的羟基首先转化为羰基，接着再转为乳酸分子上的羟基；产生的氢气和甲酸中存在大量的D，说明水分子作为反应产物参加了反应；产生的氢气和甲酸中D%超过50%，说明甘油首先发生脱水反应而不是脱氢反应，最有可能的中间产物是丙酮醇.

Abstract:

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.