SO2-4／TiO2催化合成高品质对苯二甲酸二甲酯的研究

摘要

采用沉淀-浸渍法制备固体酸SO2-4／TiO2催化剂，通过XRD， Raman， XRF， N2吸附解析， NH3-TPD等技术对催化剂进行结构和酸性能表征。以甲醇和对苯二甲酸的酯化反应为模型反应，考察了不同焙烧温度的催化剂的催化反应活性。实验结果表明：300℃焙烧的催化剂具有最大比表面积和酸性位点，反应活性最好，酯化反应转化率为95％，产物对苯二甲酸二甲酯选择性为97％。%Solid catalysts SO 2-4 /TiO2 were prepared by precipitation method with different calcination temperatures . The textural properties of the catalysts were studied by means of XRD , Raman, XRF, N2 adsorption-desorption.Acidity properties of the catalysts were tested by NH 3-TPD.Esterification of methanol and terephthalic acid over SO 2-4 /TiO2 was studied.Experimental results showed that the SO 2-4 /TiO2 calcinated at 300 ℃ presented the higher surface area and the amount of strong acid sites than the others .The SO2-4 /TiO2-300 ℃exhibited a catalytic activity with 95%conversion of terephthalic acid and 97%selectivity of dimethyl terephthalate after 3 h at 70 ℃under atmospheric pressure .