Mixed metal oxides are multifunctional catalysts applied in methanol synthesis, fatty ester to alcohol
conversion, selective hydrogenation (e.g., menthone to menthol, ketones without affecting double
bonds), N-alkylation of amines, isomerization of α-pinene to camphene, and
decarboxylation–dehydration reactions such as propionic acid to diethyl ketone.

Applications: Selective oxidation (propylene → acrolein, methanol → formaldehyde), oxidative
dehydrogenation, syngas conversion, and catalytic combustion of VOCs.
Chemical Information: Include systems such as Mo–V–Nb–Te, Cu–Zn–Al, Co–Mo, and perovskite-type
oxides (ABO₃). Catalytic activity is closely linked to oxygen vacancy concentration and lattice
redox cycles.

• General Formula: Variable, e.g. 
• Perovskites: ABO₃ (e.g., LaCoO₃, LaFeO₃)
•  Spinels: AB₂O₄ (e.g., Co₃O₄, ZnAl₂O₄)
•  Complex oxides: Mo–V–Nb–Te–Oₓ
• Structure: Crystalline oxides, often solid solutions or layered structures.
•  Surface Area: Typically 20–200 m²/g.
•  Redox Properties: Oxygen vacancies (O²⁻ ↔ ½O₂ + 2e⁻) crucial for activity.