还原剂和水蒸汽对钯催化NO还原反应性能的影响  

Effects of reductants and steam on the palladium-catalyzed reduction of

作　　者：吴柄贤 王成雄[1,2] 徐滢 覃庆高 郭律 赵云昆 WU Bingxian;WANG Chengxiong;XU Ying;QIN Qinggao;GUO Lü;ZHAO Yunkun(State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals,Kunming Institute of Precious Metals,Kunming 650106,China;State-Local Joint Engineering Research Center of Precious Metal Catalytic Technology and Application,Kunming Sino-platinum Metals Catalysts Co.Ltd.,Kunming 650106,China)

机构地区：[1]昆明贵金属研究所稀贵金属综合利用新技术国家重点实验室,昆明650106 [2]昆明贵研催化剂有限责任公司贵金属催化技术与应用国家地方联合工程研究中心,昆明650106

出　　处：《贵金属》2024年第2期52-58,共7页Precious Metals

基　　金：国家自然科学基金(No.22202094);云南省基础研究专项(No.202101AT070237);云南省高层次人才选拔专项(No.202205AC160086)。

摘　　要：为满足严格的排放法规,在控制好NO_(x)排放的同时,也需减少N_(2)O、NH_(3)等二次污染物的排放。为探究尾气组分对NO_(x)还原产物的影响,本文用催化活性模拟评价装置,对自制单钯三效催化剂,进行了还原剂种类、CO浓度及水蒸汽浓度对NO转化效率及N_(2)O和NH_(3)生成产物的影响研究。结果表明,CO催化还原NO是导致N_(2)O生成的主要原因,其内在本质在于催化剂表面活性氧物种的协同作用,NH_(3)的生成量在150~400℃范围内与反应温度正相关;水蒸汽的加入会促进N_(2)O和NH_(3)的生成,H2O分子在催化剂表面吸附作用抑制了活性氧物种的消耗;增加CO浓度可抑制N_(2)O生成但会促进NH_(3)生成。Besides controlling NO_(x) emissions,reducing the emissions of secondary pollutants including N_(2)O and NH_(3)is required to meet the strict emission regulations.In order to understand the effects of exhaust gas components on catalytic NO_(x) reduction,NO conversion as well as the formation features of N_(2)O and NH_(3)were tested on a catalytic activity simulation evaluation device and the catalytic reaction was carried out by using a self-prepared three-way catalyst under different reductants and at different concentrations of CO and steam.It was found that N_(2)O formation was significantly ascribed to the catalytic reduction of NO by CO,because of the synergistic effect of active oxygen species on the catalyst surface.And the amounts of NH_(3)formation were positively correlated with the reaction temperature in the range of 150~400℃.Introducing water vapour led to an increase in N_(2)O and NH_(3)contents and the adsorption of H2O molecules on the catalyst surface inhibited the consumption of reactive oxygen species.Increasing CO concentration would reduce N_(2)O formation but promote NH_(3)generation.

关 键 词：单钯催化剂 一氧化碳 水蒸汽 一氧化二氮 氨 

分 类 号：O643.32[理学—物理化学]