活性炭载体对醋酸乙烯合成催化剂活性的影响

选择6种活性炭为载体制备了用于合成醋酸乙烯的负载型醋酸锌催化剂,采用N2吸附、程序升温脱附、元素分析、扫描电子显微镜等表征方法,考察了活性炭载体的比表面积、孔结构、表面含氧官能团、表面形貌及化学组成对负载型醋酸锌催化剂活性的影响。研究结果发现,相对于墨水瓶孔结构的活性炭,具有平行板孔结构的活性炭更有利于反应物分子和产物分子在催化剂内表面的吸附和脱附,对应的负载型醋酸锌催化剂的活性较高;相同材质的活性炭载体中,比表面积较大、含CO的表面含氧官能团的比例较大、纯度高、灰分含量低的活性炭载体负载的醋酸锌催化剂的活性较高。

Effect of Active Carbon Supports on Catalyst Activity in Synthesis of Vinyl Acetate

Zinc acetate/active carbon catalysts were prepared by supporting zinc acetate on six kinds of active carbon separately and used in synthesis of vinyl acetate.Specific surface area,pore structure,surface oxygen functional groups,surface morphology and chemical composition of active carbon supports were investigated by means of N2 adsorption,TPD,elemental analysis and SEM.Comparing with ink-bottle-shaped pore structure,slit-like pore structure is in favor of adsorption-desorption of reactant and product molecules on inner surface of catalysts.So catalytic activity of zinc acetate supported on active carbon with slit-like pores is higher.In general,active carbon with high specific surface area,high content of surface oxygen functional groups containing C O,high carbon purity,and low ash content is appropriate to be used as support of zinc acetate catalyst in synthesis of vinyl acetate.