无机材料学报 ›› 2019, Vol. 34 ›› Issue (8): 827-833.DOI: 10.15541/jim20180523

• 研究论文 • 上一篇    下一篇

低负载量Pd/CeO2/γ-Al2O3催化剂用于低温催化氧化VOCs

李思汉,张超,吴辰亮,张荷丰,严新焕()   

  1. 浙江工业大学 化学工程学院, 绿色化学合成技术国家重点实验室培育基地, 杭州 310014
  • 收稿日期:2018-11-08 修回日期:2019-01-07 出版日期:2019-08-20 发布日期:2019-05-13
  • 作者简介:李思汉(1992-), 男, 硕士研究生. E-mail: <email>928490842@qq.com</email>
  • 基金资助:
    国家重点研发计划(2017YFC0210900);浙江省科技计划项目(2016C31104)

Pd/CeO2/γ-Al2O3 Catalyst with Low Loading for Catalytic Oxidation of VOCs

LI Si-Han,ZHANG Chao,WU Chen-Liang,ZHANG He-Feng,YAN Xin-Huan()   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
  • Received:2018-11-08 Revised:2019-01-07 Online:2019-08-20 Published:2019-05-13

摘要:

采用直接吸附法制备了Pd负载量为0.03% (质量分数)的Pd/γ-Al2O3和Pd/CeO2/γ-Al2O3催化剂, 并用于评价VOCs的催化氧化性能。通过X射线衍射(XRD)、N2吸附-脱附(BET)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、氢气程序升温还原(H2-TPR)等对催化剂的结构和表面性能进行了表征。结果表明, 在VOCs体积分数为0.1%, 空速(GHSV)为18000 mL/(g·h)条件下, Pd/CeO2/γ-Al2O3催化剂上甲苯、丙酮和乙酸乙酯实现98%转化率的温度分别为205、220和275 ℃, 比Pd/γ-Al2O3分别降低了15、15和20 ℃, 而且即使在较高的气体空速下, Pd/CeO2/ γ-Al2O3催化剂仍能展现出优异的催化氧化性能, 且具有很好的稳定性和选择性。氧化铈的加入对材料的物理化学性质和催化活性有一定的影响, 其中Pd/CeO2/γ-Al2O3含有Ce 3+和高含量的PdO, 活性物种主要以PdO形式均匀地分散在载体γ-Al2O3表面。另外, PdO与非化学计量的CeO2之间的金属-载体相互作用增强了Pd/CeO2/γ-Al2O3催化氧化性能。

关键词: Pd/CeO2/γ-Al2O3, 铈, 甲苯, 挥发性有机物, 催化氧化

Abstract:

The Pd/γ-Al2O3 and Pd/CeO2/γ-Al2O3 catalysts with 0.03wt% Pd loading were successfully synthesized via simple direct-adsorption method, and evaluated for the oxidation of volatile organic compounds (VOCs). The morphology, structure, and surface properties of the synthesized samples were characterized by X-ray diffraction (XRD), N2 adsorption-desorption (BET method), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction of H2 (H2-TPR). The temperatures for conversion of 98% toluene, acetone and ethyl acetate over the Pd/CeO2/γ-Al2O3 catalyst were 205, 220 and 275 ℃ under the conditions of VOCs volume fraction at 0.1% and gas hourly space velocity (GHSV) at 18000 mL/(g·h), respectively, which were 15, 15 and 20 ℃ lower than that of Pd/γ-Al2O3 catalyst. The Pd/CeO2/γ-Al2O3 exhibited outstanding catalytic activity, stability and selectivity even at high gas hourly space velocity. The results indicated the addition of ceria to alumina influenced the physico- chemical properties of the materials and their catalytic activities. It also revealed that Pd/CeO2/γ-Al2O3 possessed Ce 3+and high content of PdO, and the main active PdO species were well-dispersed on the surface of the γ-Al2O3 support. In addition, the strong metal-support interaction between PdO and non-stoichiometric cerium oxides enhanced catalytic performance of the Pd/CeO2/γ-Al2O3 for oxidation of VOCs.

Key words: Pd/CeO2/γ-Al2O3, cerium, toluene, Volatile organic compounds (VOCs), catalytic oxidation

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