摘要
采用理论计算方法研究了果糖脱水转化为5-羟甲基糠醛(HMF)的反应历程,系统考察了环果糖经历环状呋喃衍生物中间体转化为HMF和链果糖经历烯二醇中间体转化为HMF的反应机理。结果表明,该转化过程由质子化、脱水和去质子等一系列基元反应组成。环果糖易于被质子化,去质子化反应由于能垒较高成为转化过程的决速步骤。在链果糖的转化过程中,质子化反应则成为决速步骤。反应体系中水的存在会促进环果糖的转化,但对链果糖的转化却表现出一定的抑制作用。
A density functional theory study was conducted on the dehydration processes of fructose to 5-hydroxymethylfurfural （HMF） through both a series of cyclic furan intermediates and the acyclic intermediates on the enediol pathways, together with various secondary reactions. The conversion reactions are composed of several elementary reactions, such as protonation, dehydration, and deprotonation. For acyclic fructose, the activation barrier for protonation step is higher which thus determines the overall reaction rate. However, for cyclic fructose, it is easy to be protonized, and deprotonation turns out to be the rate-determining step. The presence of water in the reaction medium will promote the conversion of cyclic fructose by facilitating the deprotonation step, but will inhibit the dehydration of aeyclic fructose by retarding the protonation step.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2010年第1期73-81,共9页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金(20803005)
教育部新世纪优秀人才支持计划(NCET20420268)
"111"引智计划
大连理工大学青年教师培养基金项目(2007009)资助
