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.
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)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
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)~~
