Mesoporous LaMnO3 perovskite catalysts with high surface area were synthesized by using the recently developed hard templating method designated as ＂nanocasting＂.Ordered mesoporous silica designated as SBA-15 was us...Mesoporous LaMnO3 perovskite catalysts with high surface area were synthesized by using the recently developed hard templating method designated as ＂nanocasting＂.Ordered mesoporous silica designated as SBA-15 was used as the hard template.It was found that the surface area of the nanocast perovskites can be tuned（80–190 m2/g）by varying the aging temperature of the SBA-15 template.Nanocast LaMnO3 catalysts showed high conversion efficiencies for the total oxidation of methanol under steady state conditions,the one with the highest value of surface area being the best catalysts,as expected.Kinetic studies were performed for all of the synthesized catalysts.Rate constants were found to vary in accordance with the specific surface area of the nanocast catalyst which depends on the aging temperature of the parent template.From the rate constants obtained from experimental conversions at various space velocities（19500 to 78200 h〈sup〉–1）,values of activation energy and pre-exponential factor for the three nanocast LaMnO3 catalysts were determined by the linear regression of the Arrhenius plot.It is observed that the activation energy for all the catalysts remain constant irrespective of the variation in specific surface area.Further,a linear relationship was found to exist between the pre-exponential factor and specific surface areas of the catalysts indicating that the rates per unit surface area remains the same for all the catalysts.展开更多
Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supp...Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supported catalysts in catalytic methane combustion due to excellent hydrothermal stability and sulfur resistance. Recently, the emergence of nanostructured perovskite oxides（such as threedimensional ordered nanostructure, nano-array structure） with outstanding catalytic activity has further driven methane catalytic combustion research into spotlight. In this review, we summarize the recent development of nanostructured perovskite oxide catalysts for methane combustion, and shed some light on the rational design of high efficient nanostructured perovskite catalysts via lattice oxygen activation,lattice oxygen mobility and materials morphology engineering. The emergent issues needed to be addressed on perovskite catalysts were also proposed.展开更多
基金supported by the the National Science and Engineering Research Council(Canada)the Fonds Québécois de la Recherche sur la Nature et les Technologies(Province of Quebec)
文摘Mesoporous LaMnO3 perovskite catalysts with high surface area were synthesized by using the recently developed hard templating method designated as ＂nanocasting＂.Ordered mesoporous silica designated as SBA-15 was used as the hard template.It was found that the surface area of the nanocast perovskites can be tuned（80–190 m2/g）by varying the aging temperature of the SBA-15 template.Nanocast LaMnO3 catalysts showed high conversion efficiencies for the total oxidation of methanol under steady state conditions,the one with the highest value of surface area being the best catalysts,as expected.Kinetic studies were performed for all of the synthesized catalysts.Rate constants were found to vary in accordance with the specific surface area of the nanocast catalyst which depends on the aging temperature of the parent template.From the rate constants obtained from experimental conversions at various space velocities（19500 to 78200 h〈sup〉–1）,values of activation energy and pre-exponential factor for the three nanocast LaMnO3 catalysts were determined by the linear regression of the Arrhenius plot.It is observed that the activation energy for all the catalysts remain constant irrespective of the variation in specific surface area.Further,a linear relationship was found to exist between the pre-exponential factor and specific surface areas of the catalysts indicating that the rates per unit surface area remains the same for all the catalysts.
基金the financial support from the Recruitment Program of Global Young Experts Start-up Fundthe Program of Introducing Talents of Discipline to Universities of China(111 Program, No. B17019)
文摘Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supported catalysts in catalytic methane combustion due to excellent hydrothermal stability and sulfur resistance. Recently, the emergence of nanostructured perovskite oxides（such as threedimensional ordered nanostructure, nano-array structure） with outstanding catalytic activity has further driven methane catalytic combustion research into spotlight. In this review, we summarize the recent development of nanostructured perovskite oxide catalysts for methane combustion, and shed some light on the rational design of high efficient nanostructured perovskite catalysts via lattice oxygen activation,lattice oxygen mobility and materials morphology engineering. The emergent issues needed to be addressed on perovskite catalysts were also proposed.
