Pt/ZrO2 is an active and stable catalyst for methane- carbon dioxide reforming reaction. The reaction between CO2 and CH4 to yield synthesis gas might proceed via two different pathways. At high temperatures (>1075K) CO2 can be dissociated on Pt to CO and adsorbed oxygen. Methane can be dissociated to H2 and carbon at temperatures above 775K. Recombination of the adsorbed oxygen and carbon yields a second CO molecule. At low temperatures i.r. studies of CO2 adsorption on Pt/ZrO2 showed that CO was formed and in addition carbonates were formed on the support. A linear relationship between the activity and the Pt-ZrO2 perimeter length indicates that the support might be important for activating carbon dioxide and subsequent reaction with carbon.