利用溶胶-凝胶法制备Mn-Ce-O_x催化剂,考察了锰铈摩尔比和焙烧温度对催化剂催化氧化NO活性的影响,并对空速和稳定性进行了探究。结果表明,锰铈摩尔比为1,焙烧温度为300℃和400℃时,催化剂的NO氧化活性最佳。不同焙烧温度的催化剂中,400...利用溶胶-凝胶法制备Mn-Ce-O_x催化剂,考察了锰铈摩尔比和焙烧温度对催化剂催化氧化NO活性的影响,并对空速和稳定性进行了探究。结果表明,锰铈摩尔比为1,焙烧温度为300℃和400℃时,催化剂的NO氧化活性最佳。不同焙烧温度的催化剂中,400℃焙烧,催化剂呈片状结构,比表面积最大,可达113.8 m^2/g;其具有良好的稳定性,在NO体积分数为600μL/L,O_2的体积分数为4%,N2作平衡气,空速为480 000 m L/(g·h),反应温度为260℃时,NO催化氧化活性最高可达89%;进一步增大空速至960 000 m L/(g·h),相同反应条件下,NO催化活性最高可达69%。展开更多
A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibi...A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.展开更多
文摘利用溶胶-凝胶法制备Mn-Ce-O_x催化剂,考察了锰铈摩尔比和焙烧温度对催化剂催化氧化NO活性的影响,并对空速和稳定性进行了探究。结果表明,锰铈摩尔比为1,焙烧温度为300℃和400℃时,催化剂的NO氧化活性最佳。不同焙烧温度的催化剂中,400℃焙烧,催化剂呈片状结构,比表面积最大,可达113.8 m^2/g;其具有良好的稳定性,在NO体积分数为600μL/L,O_2的体积分数为4%,N2作平衡气,空速为480 000 m L/(g·h),反应温度为260℃时,NO催化氧化活性最高可达89%;进一步增大空速至960 000 m L/(g·h),相同反应条件下,NO催化活性最高可达69%。
基金supported by the National Basic Research Program of China (973 Program, 2010CB732304)the National High Technology Research and Development Program of China (863 Program, 2013AA065302)the National Natural Science Foundation of China (51202126)~~
基金supported by the National Natural Science Foundation of China(21177160,21303263,21477164)Beijing Nova Program(Z141109001814072)+1 种基金Specialized Research Fund for the Doctoral Program of High Education of China(20130007120011)the Science Foundation of China University of Petroleum-Beijing(2462013YJRC13,2462013BJRC003)~~
文摘A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.
