Activation of methane, oxygen and nitrous oxide over surface-doped MgO materials: I. Conversions in N2O, (N2O + CH4) and (O2 + CH4) reactants

The following materials have been prepared having monolayer equivalent loadings of the indicated dopants: Li⁺/MgO, Ca²⁺/MgO, Sr²⁺/MgO and Ba²⁺/MgO. A continuous-flow microcatalytic reactor system has been used to compare activities of these surface-doped materials for : (a) the catalytic dissociation of N₂O alone at 760K and 958K; (b) N₂O dissociation accompanied by methane coupling and oxidation in a flow of (N₂O + CH₄) reactants at temperatures 760–958K; (c) Methane coupling and oxidation in (O₂ + CH₄) at temperatures 760–993K. The methane-activation roles proposed for various surface sites/intermediates on MgO-based materials are reconsidered in the light of these results.