镧及其引入方式对锆交联累托土固体酸催化剂性能的影响  

The Dependence of the Capability of Zr-pillared Clay Solid Acid Catalysts on Methods of Introducing La

作　　者：郭锡坤[1] 谌宁[1] 杨阳[1] 

机构地区：[1]汕头大学化学系,广东汕头515063

出　　处：《分子催化》2004年第3期179-184,共6页Journal of Molecular Catalysis(China)

基　　金：广东省科技计划项目(2003C33004);广东省教育厅自然科学研究项目(20064);汕头大学研究与发展基金资助.

摘　　要：以累托土为基质,采用不同的方式引入La,制备了三种含La的SO42-改性锆交联粘土固体酸催化剂.采用XRD,DTA,TG等分析手段对催化剂进行表征,考察了La不同的引入方式对其热稳定性和催化活性的影响.实验结果表明,先用La交换累托土,再与Zr交联剂进行交联,制得的交联粘土的热稳定性显著提高,其DTA谱图上的羟基脱除吸热峰峰温较改性前提高了63℃,500℃焙烧后催化剂仍能保持较规整的层结构.该催化剂用于乙酸和正丁醇的酯化反应能使乙酸转化率达到97.65%,反复再生使用四次后,乙酸转化率仅下降3.83%.Three La-containing Sulfated Zr-pillared rectorite solid acids with rectorites as matrix were prepared from different methods of introducing La as additive and characterized by XRD, DTA and TGA techniques and their thermal stability and catalytic activity were investigated. The results showed that thermal stability of the resulting catalysts was much improved by exchanging Na-rectorite first with LaCl_3 solution and followed by pillaring with Zr pillaring agent. The temperature of endothermal peak for dehydroxylation in the DTA curve increased 63 ℃. Calcination at 500 ℃ did not affect the layer structure. Among the catalysts, the SO_4^(2-)/La-Zr-CLR sample showed the best activity i.e.a conversion of HAc as high as 97.65%, and good stability i.e. the fourth use of this catalyst revealed only 3.83 percentage point decrease in the conversion of HAc.

关 键 词：交联粘土 固体酸催化剂 热稳定性 镧助剂 酯化 

分 类 号：O643.32[理学—物理化学]