V_2O_5/CeO_2催化剂上甲醇氧化一步法合成二甲氧基甲烷

One-Step Oxidation of Methanol to Dimethoxymethane on V_2O_5/CeO_2 Catalyst

采用溶胶-凝胶法制备了V2O5/CeO2催化剂,并用于甲醇氧化一步法合成二甲氧基甲烷(DMM)反应中.考察了V2O5含量对钒氧化物的存在状态、催化剂表面酸性、氧化-还原性及其催化甲醇氧化反应性能的影响.结果表明,V2O5含量为15%时钒氧化物呈单层分散,小于15%时以孤立或聚合态存在,大于20%时出现V2O5晶体,达到30%时出现CeVO4.当V2O5含量为15%时,较高的钒氧化物分散度使催化剂具有较强的氧化还原能力和较多的酸性中心,从而使催化剂具有较高的活性和DMM选择性.

The V2O5/CeO2 catalyst samples were prepared by the sol-gel method and applied in the methanol partly oxidation.The influence of V2O5 content on the existing state of vanadia and surface properties as well as the catalytic performance was studied.The results showed that the vanadia was monolayer dispersed with V2O5 content was 15%,aggregated as V2O5 crystalline with above 20%,and formed CeVO4 with 30%.The higher dispersion of vanadia can lead to stronger reducibility and more acidic sites,which were closely related to the higher methanol conversion and dimethoxymethane selectivity.