石油学报（石油加工）
石油學報（石油加工）
석유학보（석유가공）
ACTA PETROLEI SINICA(PETROLEUM PROCESSING SECTION)
2010年
1期
73-81
,共9页
聂小娃%刘新%刘民%宋春山%郭新闻
聶小娃%劉新%劉民%宋春山%郭新聞
섭소왜%류신%류민%송춘산%곽신문
果糖%脱水%5-羟甲基糠醛(HMF)%密度泛函理论(DFT)
果糖%脫水%5-羥甲基糠醛(HMF)%密度汎函理論(DFT)
과당%탈수%5-간갑기강철(HMF)%밀도범함이론(DFT)
fructose%dehydration%5-hydroxymethylfurfural (HMF)%density functional theory(DFT)
采用理论计算方法研究了果精脱水转化为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.
採用理論計算方法研究瞭果精脫水轉化為5-羥甲基糠醛(HMF)的反應歷程,繫統攷察瞭環果糖經歷環狀呋喃衍生物中間體轉化為HMF和鏈果糖經歷烯二醇中間體轉化為HMF的反應機理.結果錶明,該轉化過程由質子化、脫水和去質子等一繫列基元反應組成.環果糖易于被質子化,去質子化反應由于能壘較高成為轉化過程的決速步驟.在鏈果糖的轉化過程中,質子化反應則成為決速步驟.反應體繫中水的存在會促進環果糖的轉化,但對鏈果糖的轉化卻錶現齣一定的抑製作用.
채용이론계산방법연구료과정탈수전화위5-간갑기강철(HMF)적반응역정,계통고찰료배과당경력배상부남연생물중간체전화위HMF화련과당경력희이순중간체전화위HMF적반응궤리.결과표명,해전화과정유질자화、탈수화거질자등일계렬기원반응조성.배과당역우피질자화,거질자화반응유우능루교고성위전화과정적결속보취.재련과당적전화과정중,질자화반응칙성위결속보취.반응체계중수적존재회촉진배과당적전화,단대련과당적전화각표현출일정적억제작용.
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 acyclic fructose by retarding the protonation step.
