The aim of this work was the study and development of aluminum-pillared clay (Al-PILC)-based monolithic Pd catalysts for reducing NOx emissions from natural gas-fired power plants using methane as a selective reductant. During preparation of the support, the same raw material used to synthesize the pillared clays was used as a permanent inorganic binder. This confers high surface area and acidity to the extrudates, in addition to high hydrothermal resistance and mechanical strength. The influence of the method used for active phase incorporation on the physico-chemical properties and DeNO(x) activity and selectivity was studied. Conclusions were drawn from the use of different solution pH values and precursors in relation to the isoelectric point of the solid. Characterization was carried out using X-ray diffraction, inductively coupled plasma-optical emission spectroscopy, X-ray photoelectron spectroscopy, N-2 adsorption, and NH3 and CO chemisorption. (c) 2005 Published by Elsevier B.V.