Ru/α-MnO_(2)催化剂形貌对NH_(3)-SCO反应性能的影响  

Effect of the morphology of Ru/α-MnO_(2)on NH_(3)-SCO performance

作　　者：李盼 马俊洋 陈志豪 王丽[1] 郭耘[1] LI Pan;MA Junyang;CHEN Zhihao;WANG Li;GUO Yun(Institute of Industrial Catalysis,School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化学与分子工程学院工业催化研究所,上海200237

出　　处：《化工学报》2023年第7期2908-2918,共11页CIESC Journal

基　　金：国家自然科学基金项目(21976057)。

摘　　要：以具有不同形貌的线状(w)、管状(t)和棒状(r)的α-MnO_(2)为载体制备了Ru/α-MnO_(2)催化剂,考察了载体形貌对于氨选择性催化氧化(NH3-SCO)反应性能的影响,并利用多种手段表征了催化剂的物化性质、氧化还原性能和酸性。α-MnO_(2)形貌影响所暴露的晶面;线状、纳米棒和管状α-MnO_(2)分别暴露(110)、(310)和(200)晶面。Ru的引入提高了催化剂的耐水性能,其中管状Ru/α-MnO_(2)在水汽条件下NH3转化率为86%,N2的选择性为98%。Ru的引入对反应性能的影响与其对α-MnO_(2)表面酸性、氧化还原性能的影响密切相关。Ru降低了α-MnO_(2)-w表面酸量导致其活性下降;Ru对于α-MnO_(2)-r氧化性能的提高弥补了其导致的表面酸量的降低;而Ru对α-MnO_(2)-t氧化性和酸量的同时促进是Ru/α-MnO_(2)-t反应性能提升的主要原因。α-MnO_(2)with different morphology,such as wire(w),tube(t)and rod(r)were synthesized as supports to prepare Ru/α-MnO_(2),and the effects of support morphology on the ammonia selective catalytic oxidation(NH_(3)-SCO)were investigated.Meanwhile,the physical and chemical properties,redox properties and acidity of the catalysts were characterized by various methods.The exposed facet was closely related to the morphology ofα-MnO_(2),for(110),(310)and(200)crystal planes were observed on the wire-,tube-,and rod-α-MnO_(2),respectively.The introduction of Ru improves the water resistance of the catalyst,and the tubular Ru/α-MnO_(2)has a NH_(3)conversion rate of 86%and a N2 selectivity of 98%under water vapor conditions.The effects of Ru on NH_(3)-SCO activity performance was closely related to its effect on the surface acidity and redox property ofα-MnO_(2).The addition of Ru reduced the surface acid amount ofα-MnO_(2)-w and thus lowered its activity,while the improved reducibility of Ru toα-MnO_(2)-r compensated for the decreasing in the surface acid amount.However,for Ru/α-MnO_(2)-t,the simultaneous increase in reducibility and surface acid amount by the presence of Ru was the main reason for the enhancement in NH_(3)-SCO activity.

关 键 词：催化剂 载体 氧化 氨选择性催化氧化 α-MnO_(2)形貌 酸性 氧化还原性 

分 类 号：TQ137.1[化学工程—无机化工]