Mo助剂对Ni/C催化剂上甲醇羰基化性能的影响

采用等体积浸渍法制备Ｎｉ／Ｃ 及其双金属催化剂，以ＸＰＳ 和ＴＰＲ 技术表征了其表面组成和还原性能，并在加压固定床反应器装置上考察了催化剂的羰基化活性。结果表明：在Ｎｉ／Ｃ 催化剂中添加Ｍｏ 组分能削弱氧化镍与活性炭之间的相互作用，促进ＮｉＯ 的还原；适量的Ｍｏ 组分还能促进ＮｉＯ 在载体表面的分散，从而提高镍催化剂的羰基化活性，最佳ｎ（ Ｍｏ）／ ｎ（ Ｎｉ） ＝ ０－３ 。浸渍次序对羰基化活性有一定的影响，其活性顺序为先浸镍后浸钼＞共浸＞ 先浸钼后浸镍。在反应温度为２４０ ～３００ ℃、压力为０－５ ～２－５ ＭＰａ 、原料中ｎ（ＣＨ３ＯＨ）／ ｎ（ＣＨ３Ｉ） 为９ ～１９ 的反应条件下，升高反应温度和提高碘甲烷浓度均对羰基化反应有利，最佳反应条件为：３００ ℃、１－５ ＭＰａ，原料比ｎ（ＣＯ）／ ｎ（ ＭｅＯＨ）／ ｎ（ ＭｅＩ） ＝ ２１／１９／１ 。

Vapor phase carbonylation of methanol on active carbon supported Ni-Mo bimetallic catalysts

Ni Mo/C catalysts for methanol carbonylation were prepared via incipient impregnation and characterized by XPS and TPR.Activities of the catalysts were tested under pressurized conditions in the presence of methyl iodide promoter with a fixed bed reactor. The results indicated that Mo can act as a promoter,and the promotion is due to an increase in the number of active Ni centers. The activity maximum reached when Mo/Ni molar ratio was 0.3. The impregnation sequences have some effects on the catalytic activation,which is:impregnating Mo after Ni>co impregnation>impregnating Mo before Ni.Under the reaction conditions of 240～300℃,0 5～2 5MPa and feedstocks molar ratio CH 3OH/CH 3I 9～19,high reaction temperature and concentration of CH 3I were favorable for carbonylation of methanol to acetic acid and methyl acetate,and the optimum condition was 300℃,1 5MPa and feedstock molar ratios of CO/CH 3OH/CH 3I were 21/19/21.