乙醇一步合成乙酸乙酯时混合氧化物催化剂的TPD和TPR测试

Determination of TPD and TPR of Mixed Oxide Catalyst for One-step Synthesis of Ethyl Acetate from Ethanol

用NH_3-TPD、CO_2-TPD和了PR方法表征了乙醇一步合成乙酸乙酯时混合氧化物催化剂物种和还原特性。结果表明,催化剂表面同时存在酸中心和碱中心,在Cu/ZnO/CoO/Al_2O_3催化剂体系中添加TiO_2和ZrO_2或以NiO代替CoO,导致NH_3-TPD和CO_2-TPD谱的变化,TPR谱的还原峰温度大大降低并由一个还原峰分裂为二个还原峰,这些变化已被反应动力学数据证实是有利于催化性能的提高。

By means of TPD and TPR methods, the species and the redution property of mixed oxide catalyst for the one-step synthesis of ethyl acetate from ethanol were characterized. The results show that the acid centre and basa centre exist on catalyst surface simulandosly, and that changes of NH_3-TPD and CO_2-TPR or temperature decreasing and peak spliting of reduction peak were resulted from the addition of TiO_2 and ZrO_2 or NiO instead of CoO in Cu/ZnO/CoO/Al_2O_3 catalyst system. These changes were advantageous to the catalyst reactivity and it was confirmed by reaction kinetic data.