分别采用沉积沉淀法、溶胶凝胶法和蒸氨法制备Cu/SiO2 催化剂.利用N2 吸附-脱附、N2O滴定、XRD、FT-IR、H2-TPR和NH3-TPD对催化剂的物理化学性质进行表征,并考察其己二酸二甲酯加氢合成1,6-己二醇的性能.结果表明:虽然溶胶凝胶法和蒸氨法因层状硅酸铜的存在具有较高的铜分散度和表面酸性等性质,但受制于较小孔径结构,反而是传统的沉积沉淀法制备的Cu/SiO2 催化剂因较大的孔径具有更高的反应活性.在反应温度 200℃、反应压力 5.0 MPa、液时空速0.6h-1和n(氢)/n(酯)=175 的条件下该催化剂可稳定运行50 h,己二酸二甲酯的转化率可达99.8%,1,6-己二醇的选择性可达98.2%.
Cu/SiO2 catalysts were prepared by deposition precipitation,sol-gel and ammonia evapora-tion method,respectively.The physicochemical structure properties of the catalyst were characterized by N2 adsorption-desorption,N2 O titration,XRD,FT-IR,H2-TPR and NH3-TPD,and the performance of hydrogenation of dimethyl adipate(DMA)to 1,6-hexanediol(HDO)was investigated.The results showed that although the sol-gel and ammonia evaporation method had high copper dispersion and sur-face acidity due to the the presence of copper phyllosilicate structure,they are restricted by the smaller pore structure.Instead,the Cu/SiO2 catalyst prepared by the traditional deposition precipitation method had higher reaction activitydue to the larger pore.Under the conditions of reaction temperature 200℃,re-action pressure of 5.0 MPa,liquid hourly space velocity of 0.6 h-1 and molar ratio of H2 to ester of 175,the reaction could be run stably for 50 h.The conversion rate of dimethyl adipate can reach 99.8%,and the 1,6-hexanediol selectivity can reach 98.2%.