| Methanol is a very important chemical raw material and a potential fuel for automobile and fuel cell. So there is sustained interest in the research and discovery in methanol synthesis all over the world. The present low-pressure technology for methanol synthesis from syngas such as ICI and Lurgi process, which was a successful example of integration in catalysis of the chemical and engineering revolution, has still some great deficiencies such as low per-pass conversion of syngas, and high H2O content product etc. Nevertheless, the extended research indicated that it must alter the catalyst system and develop a novel catalyst system to obtain high activity and selectivity at low temperature and ensure the production with high activity (>90%) and selectivity, which is so called low temperature methanol synthesis process (LTMS). At present, the two-step mechanism what consisted of carbonylation of methanol followed by hydrogenolysis of methyl formate was accepted. Hydrogenolysis of methyl formate to methanol was the rate-determining process and was mainly catalyzed by nickel-based or copper-based catalyst system.It was the key point to develop an efficient copper-based catalyst for the hydrogenolysis of methyl formate to methanol, which has some amazing characteristics such as CO-resistant, non-pollution, and high active at low-temperature. According to the problems, the hydrogenolysis of methyl formate to methanol was studied in a fix-bed reactor using the Cu/Cr/Si catalysts in this thesis. The effects of chromium content were researched firstly. The catalytic activity was reduced with the decrease of chromium content. In this paper, the Cu/Cr/Si catalyst with the promoters such as Ca, Zr, B, Ce were prepared. The influence of different promoter and the content of promoter were investigated. These catalysts were characterized by H2-TPR, XRD and other methods. It was found that B, Zr, Ca, Ba and Mg were effective promoters for the Cu/Cr/Si catalyst with low Cr content.Part of our experimental work focused on the stimulative function of ZrO2 on Cu/Cr/Si catalyst. There was a higher activity for the catalyst added with a certain amount of Zirconium, while the selectivity of methanol was reduced slightly. The maxium yield of methanol at low temperature like 135℃ or 165℃ was obtained on the catalyst with 6wt% of Zirconium. The results of XPS and TPR characterization indicated that the state of promoter Zr in these catalysts were similar as that in zirconia, Zr presented the effect of absorbing electrons and it worked by affecting the chemical micro-environment of copper element in catalysts.CNTs were added as promoter into Cu/Cr/Si catalyst with low Cr content, and were investigated in the model reaction from the hydrogenolysis of methyl formate. It was indicated in this work that CNTs was effective promoter for the Cu/Cr/Si catalyst used in the hydrogenolysis of methyl formate. TPR,XRD and XPS results and the catalytic performance of catalysts were analyzed, which indicated that CNTs could make Cu dispersed effectively on catalyst surface, then the reduced temperature of catalysts decreases and the amount of H2 absorption increased. Colloid-precipitation method was used to prepare CuO/SiO2 catalyst. It was detected that the catalysts prepared by this method obtained higher initial activities. The effect of temperature and atmosphere on CuO/SiO2 catalyst while being caclined or reduced were studied.In summary, based on a series of experimental work, novel copper-based catalysts with low Cr content or without Cr element were prepared, which obtained high activities at low temperature. Many characterization measurements, such as XPS,XRD,TPR,TPD and TG etc were used to investigate the relationship between catalytic performance and catalyst structure. These results were helpful to understand the co-effect of each component in catalyst and also supplied some references for developing the catalyst with high activity at low temperature.
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