Nickel pyrophosphates containing metal cations were prepared from aqueous solutions. The obtained phosphates were characterized with inductively coupled plasma (ICP), differential thermal analyses (DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), specific surface area, acid strength, amount of acidic sites, and adsorbed carbon measurements. The phosphates were used as a catalyst for decomposition of trifluoromethane. The kinds and ratios of metal cation added were discussed. The nickel pyrophosphate catalysts containing magnesium had higher selectivity to CO2 and longer lifetimes than aluminum orthophosphate for decomposition of trifluoromethane. (c) 2005 Elsevier B.V. All rights reserved.