SO_4~2-/ZrO_2固体超强酸催化剂研究(Ⅳ)——邻二甲苯与苯乙烯的烷基化反应

制备了SO4 2 -/ZrO2 固体超强酸催化剂 ,用Hammett指示剂法和吡啶吸附的FT -IR光谱法测定了其酸强度和酸中心类型 ;以邻二甲苯和苯乙烯生成 1-苯基 - 1- (3,4-二甲基苯基 ) -乙烷 (PXE)的烷基化为探针反应 ,研究了焙烧温度对催化性能的影响以及反应温度和苯乙烯的加料方式对产物收率的影响。结果表明 ,当焙烧温度高于 5 0 0℃ ,SO4 2 -/ZrO2 可以形成超强酸 ,其表面上同时存在Lewis酸中心和Bronsted酸中心 ;SO4 2 -/ZrO2 固体超强酸催化剂在邻二甲苯和苯乙烯的烷基化反应中表现出高催化活性 ,并没有苯乙烯的副反应发生 ;苯乙烯的加料方式对产物收率有明显影响 ;反应温度高于 10 0℃ ,反应温度对产物收率影响较小

Studies on the SO24-/ZrO2 Solid Superacid Catalysts(Ⅳ)--Alkylation of O-Xylene With Styrene

SO 4 2-/ZrO 2solid super-acid catalysts was prepared. Their acidities were determined by Hammett indicators and FT-IR spectroscopy of pyridine adsorption methods. The effects of the calcination temperatures on the catalytic properties, reaction temperatures and enriching modes of styrene on the product yields were studied by using alkylation of O-xylene with styrene as a probe reaction. It shows that solid super-acid is formed in the SO 4 2-/ZrO 2 system when calcination temperature is higher than 500 ℃ and their surfaces has Lewis and Bronsted acidic centers; SO 4 2-/ZrO 2 solid super-acid catalyst has high catalytic activities in the alkylation of O-xylene with styrene, and there is no polymerization reaction of styrene. The enriching modes of styrene effects product yields observably,the reaction temperatures effects product yields very little when reaction temperature is higher than 100 ℃.