Research Of Dimethy Ether With Oxygen To Methyl Formate Of WO₃/MoO₃-SnO₂ Catalyst

Methyl formate is a new starting materials and structure of the unit after chemical methane, methanol chemistry, and chemical syngas in C1 chemistry. Methyl formate has a very wide range of purpose in the industrial and agricultural production. Methyl formate is a kind of high octane number gasoline additive, instead of more expensive methyl tert-butyl ether in the industrial. It also can be used as pesticide, cereal fumigants, tobacco treatment agent, fungicide, and the fruit of desiccant, etc. in the agricultural. Starting from methyl formate preparation can also be a variety of downstream products, for example, formic acid, acetic acid, dimethyl carbonate, glycolic acid methyl ester, propionic acid methyl ester and other downstream products, methyl formate has the very broad application prospects visibly. Using the direct preparation of dimethyl ether oxidation of methyl formate is a new method of synthesis of methyl formate, so we do the research of catalytic oxidation reaction of dimethyl ether to methyl formate in the thesis.According to the different content of WO₃ added in this paper, we preparate series of WO₃/MoO₃-SnO₂ catalysts, weighing12.271 gSnCl4·5H2O and 6.179 g（NH4）6Mo7O₂4·4H2O,then was obtained MoO₃-SnO₂ and explore which content of WO₃ catalyst have the highest activity, and we use the catalyst in the oxidation reaction of dimethyl ether with oxygen. The structure characteristics of the catalysts were characterized by XRD, NH₃-TPD, CO₂-TPD and Raman means. Under different conditions we do the reaction experiments and find the optimal reaction conditions according to the experimental results（n（DME）/n（O₂）=1、T=150℃、LHSV=600 h-1、Catalyst Loading=3 ml）. At this time, the conversion rate of dimethyl ether was92.2%, the selectivity of methyl formate was 57.1%.In addition, we modified the catalyst by adding different kinds of molecular sieves HZSM-5、HMCM-22 and HMCM-56, the content is 1 g. The molecular was holding of the catalyst was 2%.The modified catalysts were characterized by XRD, NH₃-TPD, Raman and SEM means. We find the most suitable modified molecular sieve combined with the experimental data. The optimum experimental conditions are similar to the above conditions, the experimental results show that the activity of the catalyst was further improved. The conversion rate of dimethyl ether was 91.6%, it has a slight decline, but the selectivity of methyl formate was up to 80.7%, And it has larger extent increase before modification.