“…Due to the wide variety of chemical compositions, they are very efficient catalysts in different reactions. Mg,Al-mixed oxides, for example, are active for base-catalyzed reactions such as aldol condensation of aldehydes and ketones, condensation of the carbonyl group with compounds presenting methylene activated groups (for example, Knoevenagel and Claisen-Schmidt reactions), alkene isomerization, alkylation of diketones and phenols, alkene epoxidation activated by hydrogen peroxide 4,[10][11][12][14][15][16][17][18][19][20][21] . HTLCs containing transition metals such as Ni, Co, Cu or Zn or noble metals such as Rh and Ru [22][23][24][25][26][27] have also been used as precursors for hydrogenation or redox catalysts for methanol synthesis from syngas 28 , removal of SOx and NOx from FCC effluents 29,30 and other redox reactions.…”