No abstract

NiO and NiO containing 1 mole % of Li+ and Cr3+ ions were found to be inert towards CH4 at temperatures below 400°C when the oxides had been annealed in oxygen. After partial reduction with CHq at t > 400°C the oxides were active from 200 to 450°C.Methane was adsorbed to a small extent on NiO and NiO-Cr203 at 200-300°C and to a relatively large extent on NiO-LizO.Maximum adsorption was observed at ca. 250°C and the adsorption on NiO-Liz0 was reversible. The capacity of each oxide to absorb CHq decreased with progressive reduction of the oxide and finally disappeared. The activity of the reduction-reaction leading to C02 and H2O increased with reduction of the NiO to a reproducible maximum. It was shown that the addition of CO to the gas phase inhibits the reduction-reaction and the deceleration of the reaction with CHq is attributed to the accumulation during the reaction of irreversibly adsorbed CO.