Alumina-supported manganese- and manganese-palladium oxide catalysts for VOCs combustion

Alumina-supported manganese- and palladium-manganese oxide catalysts were prepared and tested in the combustion of formaldehyde. Total combustion of formaldehyde/methanol was achieved at 220degreesC over a 18.2% Mn/Al2O3 catalyst. This temperature decreased either to 90 or 80 upon adding 0.1% or 0.4% Pd, respectively, to the base 18.2% Mn/Al2O3 catalyst. The combined use of X-ray diffraction, temperature-programmed reduction and photoelectron spectroscopy (XPS) techniques revealed that a Mn4+/Mn3+ oxide(s) and PdOx species are present on the surface of the fresh catalysts and remain along the catalytic reaction. (C) 2003 Elsevier Science B.V. All rights reserved.