ABSTRACT
A catalyst composed of a Pd(5)Cu mixed oxide supported over Al(2)O(3)-CeO(2) with general formula Pd(5)CuO(x)/Al(2)O(3)-CeO(2) (Al/Ce atomic ratio=1/1) has been prepared by a wet impregnation method and tested in the methanol conversion. The structural and morphological characterization of the catalyst evidences that it is a mesoporous material thermally stable up to 873 K. At that temperature the specific surface area value is 170 m(2)/g, and a CeO(2) cubic phase is identified together with ill-defined diffraction peaks tentatively assigned to Cu-Pd clusters, suggesting that the active phase is well dispersed over the support. Infrared studies prove that methanol conversion takes place over the catalyst to a high extent yielding syngas as main product in the range 473-723 K and methane at higher temperatures. Oxygenated intermediates containing methoxy, carbonile or formiate species are not detected, which evidences that methanol conversion to methane very probably takes place according to a via-carbide mechanism.
