WO_(3)改性Cu/CeO_(2)催化剂选择性催化氧化乙二胺的性能研究

Study on performance of WO_(3)modified Cu/CeO_(2)catalyst in selective catalytic oxidation of ethylenediamine

以CeO_(2)为载体、Cu物种为主要活性位点,采用浸渍法制备了一系列WO_(3)改性Cu/CeO_(2)催化剂。研究了WO_(3)质量分数对乙二胺(EDA)选择性催化氧化(SCO)性能的影响,并通过XRD、XPS、H_(2)-TPR、NH_(3)-TPD等方法对催化剂的物理化学性质进行了分析表征。结果表明,WO_(3)改性的Cu/CeO_(2)催化剂的N2选择性大幅提高,其中Cu/5W/CeO_(2)在337℃时对EDA实现了100%的转化率,该温度条件下NO_(x)的浓度大幅降低,同时具有较好的活性和选择性。表征结果表明,WO_(3)的引入显著提高了催化剂的酸性位点数量,促进了对反应副产物NO_(x)的催化还原,提高了反应的N2选择性。

A series of WO_(3)-modified Cu/CeO_(2)catalysts are prepared through impregnation method with CeO_(2)as the support and Cu species as the main activity checking point.The effect of WO_(3)mass fraction on the performance of the catalysts in selective catalytic oxidation of ethylenediamine(EDA)is studied,and the physicochemical properties of the catalysts are analyzed and characterized by means of XRD,XPS,H_(2)-TPR,NH_(3)-TPD,and other methods.It is indicated that WO_(3)-modified Cu/CeO_(2)catalyst delivers a much higher N2 selectivity than the unmodified one.Among them,Cu/5W/CeO_(2)achieves a 100%conversion rate of EDA at 337℃,and the concentration of NO_(x)is significantly reduced at this temperature.In addition,it has good activity and selectivity.The characterization results show that the addition of WO_(3)substantially improves the number of acidic site of the catalyst,promotes the catalytic reduction of the NO_(x)by-product from the reaction,and improves the N2 selectivity in the reaction.