负载型Pd-Cu催化剂的制备及富氢气氛下CO优先氧化性能  

Preparation of Supported Pd-Cu Catalyst and Its Preferential Oxidation of CO Under Hydrogen-rich Atmosphere

作　　者：赵婉君 李潇[1,2] 党慧 王永钊 赵永祥[1] ZHAO Wanjun;LI Xiao;Dang Hui;WANG Yongzhao;ZHAO Yongxiang(Engineering Research Center of Ministry of Education for Fine Chemicals,2.School of Chemistry and Chemical Engineering,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学精细化学品教育部工程研究中心,太原030006 [2]山西大学化学化工学院,太原030006

出　　处：《高等学校化学学报》2022年第3期112-123,共12页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:U1710221);山西省自然科学基金(批准号:201801D121043)资助。

摘　　要：分别以Al_(2)O_(3),SiO_(2)和C_(3)N_(4)为载体,通过简单浸渍法制备了3种负载型Pd-Cu催化剂(PC-Al_(2)O_(3),PC-SiO_(2),PC-C_(3)N_(4)),考察了其在室温下富氢气氛中CO优先氧化反应性能.采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、氮气物理吸附仪(N_(2)-physisorption)、氢气程序升温还原(H_(2)-TPR)、二氧化碳程序升温脱附(CO_(2)-TPD)、X射线光电子能谱(XPS)和原位漫反射傅里叶变换红外光谱(In situ DRIFTS)等手段对其进行了表征.结果表明,与PC-SiO_(2)和PC-C_(3)N_(4)相比,PC-Al_(2)O_(3)具有更高的CO优先氧化性能.这是由于PC-Al_(2)O_(3)上形成了大量与Pd物种具有强相互作用的Cu_(2)Cl(OH)_(3)物种;而PC-SiO_(2)中仅有少量的Cu_(2)Cl(OH)_(3),且与Pd物种相互作用较弱;PC-C_(3)N_(4)中Cu物种则更易与C_(3)N_(4)基质配位,由此削弱了Pd,Cu之间的相互作用.在反应气氛下PC-Al_(2)O_(3)表面还易形成具有更强CO活化能力的Pd+物种,通过与大量Cu^(+)物种紧密相互作用,在一定程度上抑制Pd^(+)被过度还原为Pd^(0),从而维持了其催化活性.与SiO_(2)和C_(3)N_(4)相比,Al_(2)O_(3)更适合负载Pd-Cu用于富氢气氛下CO优先氧化反应.Three supported Pd-Cu catalysts(PC-Al_(2)O_(3),PC-SiO_(2),PC-C_(3)N_(4))were prepared by a simple impregnation method using Al_(2)O_(3),SiO_(2),and C_(3)N_(4) as supports.And their catalytic performance toward CO preferential oxidation at room temperature were investigated.XRD,FTIR,N_(2)-physisorption,H_(2)-TPR,CO_(2)-TPD,XPS and in situ DRIFTS were used for analysis and characterization.The results show that compared with PC-SiO_(2) and PC-C_(3)N_(4),PC-Al_(2)O_(3) shows better CO preferential oxidation performance,which is due to the formation of a large number of Cu_(2)Cl(OH)_(3) species with strong interaction with Pd species on PC-Al_(2)O_(3).However,PC-SiO_(2) exists only a small amount of Cu_(2)Cl(OH)_(3) and its weaker interaction with Pd species.In addition,Cu species in PC-C_(3)N_(4) is more likely to coordinate with C_(3)N_(4) matrix,which weakens the interaction between Pd and Cu.Above all,Pd+species with stron⁃ger CO activation ability readily emerge on the surface of PC-Al_(2)O_(3) in the reaction atmosphere,which possess the close interaction with a large number of Cu^(+) species.And this can inhibit the complete reduction of Pd^(+) to Pd^(0) to a certain extent,so as to maintain its catalytic activity.Hence,compared with SiO_(2) and C_(3)N_(4),Al_(2)O_(3) is more suitable for supporting Pd-Cu for CO preferential oxidation in hydrogen.

关 键 词：Wacker型催化剂 Pd-Cu催化剂 CO优先氧化 载体效应 

分 类 号：O643.36[理学—物理化学]