摘要
采用半经验AM1计算方法 ,利用静态理论对噻吩在分子筛催化剂上的催化裂化脱硫机理进行了量子化学计算研究 ,通过对噻吩分子和可能产生的中间正碳离子的量子化学计算 ,得到各中间反应所需的能量 ,从而判断噻吩催化裂化脱硫反应的趋势 ,证实了氢转移反应在催化裂化脱硫中所起的作用 .当噻吩处在催化裂化条件下 ,正碳离子反应活跃 ,易与烷烃裂化生成的α烯烃加成 ,进一步与烷烃发生氢转移饱和后裂化脱硫 .由于氢转移反应为放热反应 ,因而降低反应温度有利于噻吩催化裂化脱硫 .
The mechanism of catalytic desulfurization of thiophene on molecular sieve catalyst has investigated with quantum-chemistry by using the semi-empirical AM1 calculation method and the static theory. Reaction trends of catalytic desulfurization of thiophene were determined based on the reaction energy needed, which was obtained with the AM1 calculation results of thiophene and possible carbonium ions on transition state.It was validated that the hydrogen transfer reaction played an important role in the catalytic desulfurization process. While thiophene molecules were under the catalytic cracking conditions, their carbonium ions were very active and reacted easily with α-olefins from the paraffin cracking reaction. Further, the catalytic cracking desulfurization took place by hydrogen transfer reactions with paraffin molecules. The hydrogen transfer reactions were exothermic, so a reduced reaction temperature was in favor of the catalytic cracking desulfurization of thiophene.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2004年第1期87-90,共4页
CIESC Journal
关键词
噻吩
量子化学
催化裂化脱硫
AM1
正碳离子
氢转移
thiophene, quantum chemistry,catalytic desulfurization,AM1 calculation, carbonium ion, hydrogen transfer
