Journal of Molecular Catalysis A-Chemical, Vol.372, 128-136, 2013
Effect of titania polymorph on the properties of CuO/TiO2 catalysts for trace methane combustion
Anatase and rutile have the same chemical composition as TiO2 but different crystalline structures and surface structures, which draws effect on the properties of their supported catalysts. Additionally, titania mixture, e.g., Degussa P25, which consists of both anatase and rutile, presents different physicochemical properties with anatase and rutile. In this work, P25-, anatase- or rutile-supported copper oxide catalysts (signed as CuO/P25, CuO/A and CuO/R) were prepared and characterized to study the titania support effect on the physicochemical properties and catalytic properties for the trace CH4 combustion. It is found that the activity of CuO/R is better than the corresponding CuO/A sample when their pore size and specific surface area are comparable, which is attributed to the different chemical states of the copper oxide caused by the different TiO2 support polymorphs. The loading of CuO and subsequent calcination promotes more significant sintering and anatase to rutile transform for CuO/P25 than those for CuO/A. Thus, CuO/R shows better stability than CuO/P25. (C) 2013 Elsevier B.V. All rights reserved.