不同Sr引入方式对LaCoO3钙钛矿NOx储存-还原性能的影响

摘要为提高LaCoO₃钙钛矿的NO_x脱除性能，分别采用柠檬酸络合法、浸渍法和机械混合法制备了添加Sr的LaCoO₃钙钛矿系列催化剂，并通过透射电镜（TEM）、X射线粉末衍射（XRD）和红外（FT-IR）技术对催化剂进行了表征，考察了不同制备方法对催化剂的结构和性能的影响。结果表明，加入Sr后催化剂的NO_x脱除效率大大提高。柠檬酸络合法得到的样品中部分Sr取代La进入钙钛矿晶格中，表面的SrCO₃总量较少；机械混合法得到的样品中SrCO₃晶粒较大，NO_x储存速率和释放速率都很缓慢；浸渍法得到的样品中SrCO₃晶粒小，储存快，与氧化还原中心的协同作用强，NO_x脱除效率最高。

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	郭丽红
	丁全
	田野
	李新刚

关键词：氮氧化物；碳酸锶；柠檬酸络合法；浸渍法；机械混合法

Abstract： In order to improve the NO_x removal efficiency of the LaCoO₃ perovskite, a series of Sr-introduced LaCoO₃ perovskites were prepared by three different methods of citrate acid complex method (CA), incipient impregnation method (IM) and mechanical blending method (MB). The corresponding samples were characterized by TEM, XRD and FT-IR techniques to carefully investigate the influence of different preparation methods on the structure and reactivity of the catalysts. The results show that Sr addition greatly increased the NO_x removal efficiency of the catalysts. As for the LSC-CA sample, a portion of the introduced Sr entered into the perovskite lattice so that the amount of surface SrCO₃ was less than the nominal value. The SrCO₃ grains in the LSC-MB sample had bigger sizes than those in the LSC-CA and LSC-IM samples, resulting in slower NO_x trapping and releasing rate. The LSC-IM sample had plenty of surface SrCO₃ with small grain size, which could easily trap NO_x and cooperate with the oxidation-reduction center. Therefore, among the three samples, the LSC-IM sample achieved the highest NO_x removal efficiency.

Keywords： NO_x； SrCO₃； citrate acid complex； incipient impregnation； mechanical blending

Received 2019-07-04;

Fund:国家自然科学基金（21878213）。

Corresponding Authors: 田野,E-mail:tianye@tju.edu.cn。 Email: tianye@tju.edu.cn

About author: 郭丽红(1982-),女,博士,讲师,现从事环境催化方面的研究。

引用本文:

郭丽红, 丁全, 田野, 李新刚.不同Sr引入方式对LaCoO₃钙钛矿NO_x储存-还原性能的影响[J]. 化学工业与工程, 2019,36(6): 9-16

Guo Lihong, Ding Quan, Tian Ye, Li Xingang.Effect of Sr Introduced by Different Preparation Methods on LaCoO₃ Perovskite for NO_x Storage-Reduction Reaction[J]. Chemcial Industry and Engineering, 2019,36(6): 9-16

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