摘要
基于密度泛函理论,采用B3LYP/6-31G(d,p)计算方法对乙醇为抑制剂、磺酸树脂为催化剂的异丁烯叠合反应体系进行理论研究。乙醇与异丁烯的醚化反应及异丁烯叠合反应的活化能分别为62.8 kJ/mol和167.8 kJ/mol,与异丁烯叠合反应相比,醚化反应的反应能垒较低,反应会优先发生。乙醇在苯磺酸上的物理吸附能为-71.3 kJ/mol,异丁烯在苯磺酸上的物理吸附能为-44.8 kJ/mol,物理吸附态的异丁烯容易被磺酸基上的H质子化形成烷氧基中间体,烷氧态化学吸附的吸附能为-80.2 kJ/mol。通过对比乙醇和异丁烯在苯磺酸上的吸附及两个反应的活化能,分析了乙醇在异丁烯叠合反应体系中的作用机理。
The polymerization of isobutene over sulfonic acid resin in the presence of ethanol was studied using DFT theory and B3LYP/6-31G(d,p)algorithm method.The activation energies of the etherification reaction of ethanol and isobutylene and the polymerization reaction of isobutylene are 62.8 kJ/mol and 167.8 kJ/mol,respectively.Compared with the polymerization reaction of isobutylene,the reaction energy barrier of the etherification reaction is lower and the reaction will take place preferentially.The physical adsorption energy of ethanol on benzenesulfonic acid is-71.3 kJ/mol,and the physical adsorption energy of isobutylene on benzenesulfonic acid is-44.8 kJ/mol.The physically adsorbed isobutylene is easily protonated by the H of the sulfonic acid group to form alkoxy intermediate with chemical adsorption energy of-80.2 kJ/mol.Finally,the mechanism of ethanol in the isobutene polymerization system was analyzed.
作者
刘静
肖之敏
洪学思
周晓龙
Liu Jing;Xiao Zhimin;Hong Xuesi;Zhou Xiaolong(East China University of Science and Technology,School of Chemical Engineering,Shanghai 200237;SINOPEC Shanghai Research Institute of Petrochemical Technology)
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2021年第2期33-38,共6页
Petroleum Processing and Petrochemicals
关键词
乙醇
磺酸树脂
异丁烯叠合
活化能
吸附能
ethanol
sulfonic acid resin
isobutene polymerization
activation energy
adsorption energy
