MMOs are materials 18 that can be obtained by calcination at 500-600 °C from the corresponding LDH, which is a brucite-type octahedral layer with the general formula [M 2+ 1-xM 3+ x(OH)2] x+ [A n-x/n ˑmH2O] x-, where the excess positive charge, originating from the M 2+ to M 3+ substitution, is compensated for by carbonate anions in the interlayer space. This structure is transformed into an MMO through dehydration, dihydroxylation and decarbonization of the interlayer component, giving rise to a compact structure where the oxide ions form a coordination sphere around the metal ions. From the point of view of catalysis, they are very efficient materials due to their porosity, relatively large specific surface area, reactive sites, and high thermal stability. While the use of MMOs as catalysts in the synthesis of cyclic carbonates from CO2 has been limited to the use of Mg-Al mixed metal oxides (100 °C and pressure 5 atm), 22 the use of other metals in MMOs has not been explored to date.