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介绍了甲醇选择性氧化制备二甲氧基甲烷(DMM)过程中,二元Ti O2-Al2O3氧化物载体的制备方法对V2O5/Ti O2-Al2O3催化剂性能的影响.考察的制备方法包括机械混合、球磨、沉淀、共同沉淀、溶胶凝胶法,随后通过等体积浸渍制备出V2O5/Ti O2-Al2O3催化剂.其中,溶胶凝胶法制得的V2O5/Ti O2-Al2O3催化剂具有最高的催化活性,在393 K下表现出48.9%的转化率和89%的DMM选择性,优于V2O5/Ti O2,V2O5/Al2O3催化剂.V2O5/Ti O2-Al2O3优良的性能是由于催化活性组分与混合型载体之间有效的相互作用.这种相互作用改变了活性V组分的化学态,生成了更多的V4+物种,促进了载体与活性组分之间的电子转移.此外,Ti离子可通过嵌入Al2O3晶体来生成含量适宜的酸性位,进而提高DMM的选择性.
The effect of the preparation method of binary Ti O2-Al2O3 oxide support on the performance of V2O5 / Ti O2-Al2O3 catalyst during the selective oxidation of methanol to dimethoxymethane (DMM) was investigated.The preparation methods include mechanical mixing, V2O5 / Ti O2-Al2O3 catalyst was prepared by ball-milling, precipitation, co-precipitation and sol-gel methods followed by an equal volume impregnation.The V2O5 / Ti O2-Al2O3 catalyst prepared by sol-gel method had the highest catalytic activity, K showed 48.9% conversion and 89% DMM selectivity, better than V2O5 / Ti O2, V2O5 / Al2O3 catalyst.V2O5 / Ti O2-Al2O3 excellent performance is due to the catalytic activity of the mixture with the carrier between Effective interaction that changes the chemical state of the active V component and generates more V4 + species that facilitates the electron transfer between the support and the active component.In addition, Ti ions can be incorporated into the Al2O3 crystal Generate suitable acidic sites, and thus improve the selectivity of DMM.