THERMODESORPTIONS AND THERMOREACTIONS WITH HYDROGEN OF CARBON-MONOXIDE AFTER ITS CHEMISORPTION ON A NICKEL-CATALYST .2. STRUCTURAL SENSITIVITY OF THE MATHANATION

Interrupted TPSR (Temperature Programmed Surface Reaction) followed by TPD (Temperature Programmed Desorption) (or, reversely, interrupted TPD followed by TPSR) show that the various CO adspecies do not react equally fast with H-2 but the structural sensitivity remains moderate since a single CH4 peak is displayed in the TPSR spectrum. Compensating effects are postulated in order to explain why the methanation reaction displays a moderate structure sensitivity only, in contrast with the strong structure sensivity of the CO chemisorption.