Abstract: Sn-Zr and Sn-Zr-Ce catalysts were selected as formaldehyde formation catalysts and characterized by x-ray diffraction, SPV, X-ray photoelectron spectroscopy and temperatureprogrammed desorption of O₈and n-butylamine. The activity yielding formaldehyde depends on cerium and its content. It is found that the addition of cerium lower the bonding energy of Sn, Zr and has influence on acidity of catalysts as well as adsorption of O₂, CH₄The result obtained from x-ray diffraction shows that cerium exerts action on Sn and Zr.