摘要
以三氯乙醛为亲电试剂,在HY沸石催化剂上实现了苯酚和三氯乙醛的二次缩合反应。研究了反应温度、时间、催化剂(催化剂用量、硅铝比、催化剂失活、回收和再生)、溶剂、原料配比、投料方式等反应参数对二次缩合反应的影响,筛选了催化剂,优化了反应参数。研究结果表明,硅铝比较高的HY沸石催化剂,Brnsted酸位较少,和含有孤对电子的酚羟基氧的相互作用较弱,保证了芳环的亲核性,可以较好地催化苯酚和三氯乙醛的二次缩合反应。
Condensation of phenol and chloral over HY zeolite catalysts was studied in detail.The reaction mechanism and conditions,namely reaction temperature,time,catalyst,solvent,and proportion of reactants and their addition order,were investigated.Catalyst preparation and reaction conditions were optimized.With increase of n(Si)∶n(Al),interaction between Brnsted acid sites and phenol hydroxyl weakened and nucleophilicity of aromatic ring enhanced.Therefore,HY zeolite with high n(Si) ∶n(Al)was suitable catalyst for consecutive condensation of phenol and chloral.Deactivation of the catalysts was mainly caused by strong polar reactant-phenol,by-products and stereoeffect of consecutive condensation products.Regenerated HY zeolite catalysts could be reused for many times.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2005年第5期454-459,共6页
Petrochemical Technology