Relationship between catalytic deactivation and physicochemical properties of LaMnO3 perovskite catalyst during catalytic oxidation of vinyl chloride
Relationship between catalytic deactivation and physicochemical properties of LaMnO3 perovskite catalyst during catalytic oxidation of vinyl chloride
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LaMnO3钙钛矿催化剂催化氧化氯乙烯过程中催化失活与物化性能的关系
DOI：
10.1016/j.apcatb.2015.12.052
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发表时间：
2016-06
影响因子：
22.1
通讯作者：
Giroir-Fendler Anne
中科院分区：
文献类型：
--
作者：
Zhang Chuanhui;Guo Yanglong;Giroir-Fendler Anne
研究了共沉淀法制备的lamno3钙钛矿氧化物催化剂在连续催化循环和稳态条件下对氯乙烯（VC）的氧化性能。lamno3催化剂表现出较差的催化稳定性和耐久性，随着催化活性的降低，氯化有机物质的数量增加。通过x射线衍射（XRD）、氮气吸附、热重和差热分析（TGA/DTA）、能量分散光谱（EDS）、氢程序升温还原（H2-TPR）、氧程序升温解吸（O2-TPD）和x射线光电子能谱（XPS）表征了其理化性质。新旧催化剂均呈现出典型的钙钛矿结构。在使用过的催化剂上未检测到焦炭，仅检测到微量的余氯，表明焦炭的形成和氯的侵蚀不是导致失活的原因。然而，使用过的催化剂比表面积、低温还原性和表面氧迁移率都低于新鲜催化剂，这表明物理化学和氧化还原性质对催化失活有很大影响。最后，提出了基于Mn4+/Mn3+氧化还原循环的失活机理，并推断出氯化副产物的形成与Cl种的存在和催化剂失活密切相关。
A LaMnO3perovskite oxide catalyst prepared by co-precipitation was evaluated for vinyl chloride (VC) oxidation over consecutive catalytic cycles and in steady-state conditions. The LaMnO3catalyst exhibited relatively poor catalytic stability and durability, with the amount of chlorinated organic species increasing as catalytic activity decreased. Physicochemical properties were characterized by X-ray diffraction (XRD), N2sorption, thermogravimetric and differential thermal analysis (TGA/DTA), energy disperse spectrocopy (EDS), hydrogen temperature-programmed reduction (H2-TPR), oxygen temperature-programmed desorption (O2-TPD) and X-ray photoelectron spectroscopy (XPS). Fresh and used catalysts presented a typical perovskite structure. No coke and only traces of residual chlorine species were detected on the used catalyst, indicating that coke formation and attack by chlorine were not the causes for deactivation. The used catalyst, however, presented lower specific surface area, low-temperature reducibility and surface oxygen mobility than the fresh one, suggesting that physicochemical and redox properties strongly influenced catalytic deactivation. Finally, a deactivation mechanism was proposed based on the Mn4+/Mn3+redox cycle, and the formation of chlorinated by-products was inferred to be closely related to the presence of Cl species and catalyst deactivation.
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影响因子：
22.1
作者：
Aranzabal, A.;Gonzalez-Marcos, J. A.;Magnoux, P.
通讯作者：
Magnoux, P.
影响因子：
5.5
作者：
Lima, S. M.;Assaf, J. M.;Fierro, J. L. G.
通讯作者：
Fierro, J. L. G.
影响因子：
7.3
作者：
R. López-Fonseca;J. I. Gutiérrez-Ortiz;M. A. Gutiérrez-Ortiz;J. González-Velasco
通讯作者：
R. López-Fonseca;J. I. Gutiérrez-Ortiz;M. A. Gutiérrez-Ortiz;J. González-Velasco
影响因子：
15.1
作者：
Xi-kui Wang;Chen Wang;Wen Jiang;Weilin Guo;Jing-Gang Wang
通讯作者：
Xi-kui Wang;Chen Wang;Wen Jiang;Weilin Guo;Jing-Gang Wang
影响因子：
22.1
作者：
Chuanhui Zhang;W. Hua;Chao Wang;Yanglong Guo;Yun Guo;G. Lu;A. Baylet;A. Giroir‐Fendler
通讯作者：
Chuanhui Zhang;W. Hua;Chao Wang;Yanglong Guo;Yun Guo;G. Lu;A. Baylet;A. Giroir‐Fendler