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采用共沉淀法制备了几种不同的金属氧化物催化剂(Ce-Pr-Ox、Ce-Y-Ox、Ti-PrOx、Ti-Y-Ox、Ti-Al-Ox),并对其进行了硫酸盐改性.实验同时考察了SO2-4改性对催化剂氨选择性催化还原(NH3-SCR)活性和催化剂结构组成的影响.经SO2-4改性的催化剂,NOx转化率在低温和高温均有显著提高,其中,活性最好的Ce-Pr-Ox在350~500℃范围内转化率接近100%.XRD、IR分析结果表明,催化剂经硫酸盐改性后,催化剂出现了结晶态硫酸盐;催化剂中存在M-SO2-4(M=Al,Pr和Y)键,表明了金属氧化物与硫酸盐发生了相互作用.而经SO2-4改性后催化剂优越的SCR脱硝性能与催化剂酸性位点增加密切相关.
Abstract：A series of metal oxide catalysts(Ce-Pr-Ox,Ce-Y-Ox,Ti-Pr-Ox,Ti-Y-Ox,Ti-Al-Ox) are prepared by co-precipitation method and modified by SO2-4for selective catalytic reduction of NOxwith NH3. The influences of SO2-4modification on NH3-SCR activity and structures on Ce and Ti-based catalysts are investigated. It is implied by the results that the catalytic performance of catalysts modified by SO2-4is significantly enhanced at both low and high temperatures. Furthermore,nearly 100% NOxconversion over the Ce-Pr-Oxcatalyst could be obtained throughout the temperature window of 350—500 ℃,which exhibits the highest level of NH3-SCR activity. It is also inferred from the XRD analysis that the crystalline sulfate species are detected for the SO2-4modified catalysts. Besides,the existence of sulfate species(M-SO2-4: M = Al,Pr and Y)is found on the SO2-4modified catalysts by the analysis of XRD and IR. Thus,it could be concluded that there exists interaction among SO2-4and other metal. The superior SCR activity might be attributed to the increase amount of acid cites over the SO2-4modified catalysts.
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基本信息:
DOI：
中图分类号:X701;O643.36
引用信息:
[1]张秋林,张金辉,宁平等.SO_4~(2-)改性对Ce、Ti基催化剂NH_3-SCR脱硝性能的影响[J].昆明理工大学学报(自然科学版),2014,39(06):110-115.
基金信息:
国家自然科学基金项目(21307047);; 云南省人培项目(14118682)