低负载量Pd/CeO2/γ-Al2O3催化剂用于低温催化氧化VOCs  

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

作　　者：李思汉 张超 吴辰亮 张荷丰 严新焕 LI Si-Han;ZHANG Chao;WU Chen-Liang;ZHANG He-Feng;YAN Xin-Huan(State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, ZhejiangUniversity of Technology, Hangzhou 310014, China)

机构地区：[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

出　　处：《无机材料学报》2019年第8期827-833,共7页Journal of Inorganic Materials

基　　金：国家重点研发计划(2017YFC0210900);浙江省科技计划项目(2016C31104)~~

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。The Pd/γ-Al2O3 and Pd/CeO2/γ-Al2O3 catalysts with 0.03 wt% 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.

关 键 词：Pd/CeO2/γ-Al2O3 铈 甲苯 挥发性有机物 催化氧化 

分 类 号：O614[理学—无机化学] O621[理学—化学]