CuBr2-吡啶离子液体催化甲醇液相一步氧化生成甲缩醛

One-step Oxidation of Liquid Methanol to Dimethoxymethane with CuBr2-Pyridine Ionic Liquids as Catalyst

摘要:

研究了以CuBr2与具有不同烷基支链和阴离子类型的吡啶离子液体催化剂体系对甲醇一步液相氧化合成甲缩醛（DMM）的催化性能，结果发现，CuBr2-N-乙基吡啶溴盐催化性能最好。考察了不同催化剂组成、催化剂浓度、反应温度、氧气压力、反应时间对反应的影响。结果表明，在CuBr2和N-乙基吡啶溴盐的摩尔比为1:1、催化剂质量浓度为0.04g/mL、反应温度130℃ 、氧气压力3.0MPa和反应时间4h这一优化条件下，甲醇转化率达到19.6%，DMM选择性达到 92.3%。CuBr2-N-乙基吡啶溴盐重复使用9次后，活性仍然保持稳定。

Abstract:

CuBr2-pyridine ionic liquids with different alkyl side chain and anion were used as the catalyst for one-step liquid-phase synthesis ofdimethoxymethane(DMM) by oxidation of methanol.And it was found that CuBr2-N-ethylpyridinium bromide exhibited the best catalytic activity.The Effects of composition and concentration of catalyst, reaction temperature, oxygen pressure andreaction timeon the reaction were investigated.The results show that the conversion of methanol could be 19.6% and the selectivity of DMM could reach 92.3% under the optimum conditions: n(N-ethylpyridiniumbromide):n(CuBr2) of 1:1,the catalyst concentration of 0.04g/mL, the reaction temperature of 130℃, the oxygen pressure of 3.0MPa and the reaction time of 4 hours. After being reused 9 times, the activity of CuBr2-N-ethylpyridinium bromide was still kept.