The direct synthesis of acetic acid from methane and carbon dioxide was investigated. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments showed the formation of an adsorbed acetate on both a 5% Pd/carbon and a 5% Pt/alumina catalyst when the catalyst was exposed to a mixture of methane and carbon dioxide at a temperature of about 400degreesC. Temperature programmed reaction (TPR) experiments showed the formation of gas phase acetic acid from carbon dioxide and methane at about 400 degreesC over a 5% Pt/alumina catalyst. (C) 2003 Elsevier B.V. All rights reserved.