Partial oxidation of methane on NiO-MgO-ZrO2 catalysts

► Catalysts with less Ni atoms on surface achieved a high rate of conversion. ► The greater the amount of NiO-MgO solution formed, the higher was the conversion rate of CH4. ► The large amount of NiO-MgO inhibited deactivation of Ni° active sites in POM. ► POM reaction condition oxidized Ni° of catalyst without NiO-MgO solid solution. ► MgO-ZrO2 caused oxygen dissociation that assisted conversion rates.