高等学校化学学报 ›› 2022, Vol. 43 ›› Issue (3): 20210754.doi: 10.7503/cjcu20210754

• 物理化学 • 上一篇    下一篇

负载型Pd-Cu催化剂的制备及富氢气氛下CO优先氧化性能

赵婉君1,2, 李潇1,2, 党慧1,2, 王永钊1(), 赵永祥1()   

  1. 1.山西大学精细化学品教育部工程研究中心
    2.化学化工学院, 太原 030006
  • 收稿日期:2021-11-01 出版日期:2022-03-10 发布日期:2021-12-28
  • 通讯作者: 王永钊,赵永祥 E-mail:catalyst@sxu.edu.cn;yxzhao@sxu.edu.cn
  • 基金资助:
    国家自然科学基金(U1710221);山西省自然科学基金(201801D121043)

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

ZHAO Wanjun1,2, LI Xiao1,2, Dang Hui1,2, WANG Yongzhao1(), ZHAO Yongxiang1()   

  1. 1.Engineering Research Center of Ministry of Education for Fine Chemicals
    2.School of Chemistry and Chemical Engineering,Shanxi University,Taiyuan 030006,China
  • Received:2021-11-01 Online:2022-03-10 Published:2021-12-28
  • Contact: WANG Yongzhao,ZHAO Yongxiang E-mail:catalyst@sxu.edu.cn;yxzhao@sxu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(U170221);the Natural Science Foundation of Shanxi Province, China(201801D121043)

摘要:

分别以Al2O3, SiO2和C3N4为载体, 通过简单浸渍法制备了3种负载型Pd-Cu催化剂(PC-Al2O3, PC-SiO2, PC-C3N4), 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(N2-physisorption)、 氢气程序升温还原(H2-TPR)、 二氧化碳程序升温脱附(CO2-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-SiO2和PC-C3N4相比, PC-Al2O3具有更高的CO优先氧化性能. 这是由于PC-Al2O3上形成了大量与Pd物种具有强相互作用的Cu2Cl(OH)3物种; 而PC-SiO2中仅有少量的Cu2Cl(OH)3, 且与Pd物种相互作用较弱; PC-C3N4中Cu物种则更易与C3N4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-Al2O3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Pd0, 从而维持了其催化活性. 与SiO2和C3N4相比, Al2O3更适合负载Pd-Cu用于富氢气氛下CO优先氧化反应.

关键词: Wacker型催化剂, Pd-Cu催化剂, CO优先氧化, 载体效应

Abstract:

Three supported Pd-Cu catalysts(PC-Al2O3, PC-SiO2, PC-C3N4) were prepared by a simple impregnation method using Al2O3, SiO2, and C3N4 as supports. And their catalytic performance toward CO preferential oxidation at room temperature were investigated. XRD, FTIR, N2-physisorption, H2-TPR, CO2-TPD, XPS and in situ DRIFTS were used for analysis and characterization. The results show that compared with PC-SiO2 and PC-C3N4, PC-Al2O3 shows better CO preferential oxidation performance, which is due to the formation of a large number of Cu2Cl(OH)3 species with strong interaction with Pd species on PC-Al2O3. However, PC-SiO2 exists only a small amount of Cu2Cl(OH)3 and its weaker interaction with Pd species. In addition, Cu species in PC-C3N4 is more likely to coordinate with C3N4 matrix, which weakens the interaction between Pd and Cu. Above all, Pd+ species with stronger CO activation ability readily emerge on the surface of PC-Al2O3 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 Pd0 to a certain extent, so as to maintain its catalytic activity. Hence, compared with SiO2 and C3N4, Al2O3 is more suitable for supporting Pd-Cu for CO preferential oxidation in hydrogen.

Key words: Wacker catalyst, Pd-Cu catalyst, CO preferential oxidation(CO-PROX), Carrier effect

中图分类号: 

TrendMD: