超细CuO/ZnO/TiO2-SiO2的表征和CO2加氢合成甲醇性能研究

Ultrafine Cu/ZnO/TiO2-SiO2 catalysts with different content of Cu and Zn ranging from 5% to 25% were prepared by sol-gel method. The physical-chemical properties and catalytic performance of the catalysts were studied by using FT-IR(Fourier Transform InfraRed), BET,TPR(Temperature Programmed Reaction),XRD(X-ray Diffraction) and micro-reactor system. It was found that the catalysts exhibited large BET surface area(590 m2g－1～240 m2g－1) and uniform pore distribution. XRD showed that only crystal phase detected was CuO. With increasing content of Cu and Zn in the sample, the BET surface area of the catalysts gradually decreased, the average pore diameter and the junction temperature of CuO micro-crystal increased, the dimensions of the micro-crystal increased from 10 nm to 20 nm. The presence of ZnO can promote the interaction of CuO and TiO2-SiO2 support. The catalysts showed high activity and selectivity to methanol. When the content of CuO and ZnO both were 25%, a methanol yield of 0.126/g·h－1·g cat－1 was obtained under the conditions of 260 ℃, 2.0 MPa, 2 500 h－1 with a CO2/H2 ratio of 1/3.