摘要
【目的】提高NO_(x)催化剂在中低温条件下的NO_(x)储存还原能力,实现高效NO_(x)储存还原。【方法】采用甘氨酸辅助溶液燃烧法制备钙钛矿型La_(0.5)Sr_(0.5)CoO_(3)(LSC)催化剂,通过多种表征手段对催化剂的理化性质进行表征,研究甘氨酸与硝酸根物质的量比、煅烧温度等制备条件对催化剂理化性质、NO_(x)储存性能以及催化剂的抗硫性和水热稳定性的影响。【结果】所制备的LSC催化剂在300℃条件下的NO_(x)吸附、储存性能显著提高。当物质的量比为1.6、煅烧温度为700℃时,制得的LSC催化剂具有良好的NO_(x)吸附能力(A=1889µmol·g^(-1))和NO_(x)储存能力(S=1048µmol·g^(-1));并且该催化剂经硫化及水热老化后仍保持良好的NO_(x)吸附、储存能力(A=1434µmol·g^(-1),S=1262µmol·g^(-1))。【结论】该催化剂具有较大的比表面积、较强的NO氧化能力以及存在适量的表面SrCO3物相,使其具有良好的NO_(x)储存性能。
Objective To enhance the NO_(x) storage and reduction capacity of NO_(x) catalysts under medium and low temperature conditions and achieve efficient NO_(x) storage and reduction performance.The development of an efficient and cost-effective catalyst for medium and low temperature NO_(x) storage and reduction is crucial.Methods In this study,the perovskite La_(0.5)Sr_(0.5)CoO_(3)(LSC)catalyst was synthesized utilizing the glycine-assisted solution com⁃bustion method.The physicochemical properties of the catalyst were comprehensively characterized through various analytical techniques.The impact of preparation parameters,including the molar ratio of glycine to nitrate and calcination temperature,on the NO_(x) storage performance of the catalyst was systematically investigated.Furthermore,the sulfur resistance,hydrothermal stability,and NO_(x) storage mechanism of the LSC catalyst during NO_(x) storage were thoroughly examined.Results and Discussion Based on the aforementioned characterization and experimental findings,the NO_(x) desorption curve depicted in Fig.9 illustrated that altering the amount of glycine led to a shift in the temperature of the catalyst desorption peak towards higher values,consequently enhancing the stability of nitrate species.Specifically,at a glycine-to-nitrate ratio(φ)of 1.6,the catalyst exhibited the lowest desorption peak temperature,indicative of less stable nitrate species prone to releasing NO_(x).The order of NO_(x) adsorption capacity(A)and NO_(x) storage capacity(S)of the catalyst was as follows:LSC-1.6>LSC-2.4>LSC-0.8.Upon reaching equilibrium adsorption of NO_(x),the concentrations of NO and NO_(2) in the atmosphere remained stable.The relative NO_(2) reduction(RNO2)of the catalyst followed the sequence:φ=1.6(65%)>φ=2.4(51%)>φ=0.8(49%).Notably,the LSC catalyst synthesized withφ=1.6 exhibited the highest S,A,and R_(NO2),attributed to its large specific surface area,robust NO oxidation capacity,and the presence of appropriate SrCO_(3) species.Furthermore,the NO_(x) desorpt
作者
刘剑勋
王旭东
姜若兰
赵心怡
干良然
刘伟
亓海强
王仲鹏
LIU Jianxun;WANG Xudong;JIANG Ruolan;ZHAO Xinyi;GAN Liangran;LIU Wei;QI Haiqiang;WANG Zhongpeng(School of Water Conservancy and Environment,University of Jinan,Jinan 250022,China;Zaozhuang Ecological Environment Monitoring Center of Shandong Province,Zaozhuang 277800,China)
出处
《中国粉体技术》
CAS
CSCD
2024年第3期124-138,共15页
China Powder Science and Technology
基金
国家自然科学基金项目,编号:21777055
山东省自然科学基金项目,编号:ZR2023MB100,ZR2021MB063。
关键词
溶液燃烧法
钙钛矿
氮氧化物储存
甘氨酸
solution combustion method
perovskite
NO_(x) storage
glycine
