Heterogeneous Metal Catalysts for Oxidation Reactions

Table 1

Major features, advantages, and disadvantages of the commonly used support materials.

Supports materials	Features	Advantages	Disadvantages	References
Alumina	(1) Hardness; (2) High melting point and high compression strength; (3) Resistant to abrasion and chemical attack; (4) High thermal conductivity	(1) Thermally stable; (2) Randomly ordered; (3) High surface area and pore volume; (4) Well-ordered pore; (5) Narrow pore size	(1) Difficult to control the hydrolysis rate of aluminum precursors	[73]
Silica	(1) Tendency to form large networks; (2) Found in nature and living organisms; (3) Hardness	(1) High efficiency; (2) High selectivity; (3) Highly stable; (4) Mechanical strength	(1) Low compatibility; (2) Formation of aggregates/agglomerates	[74]
Zeolite	(1) Microporous; (2) Inertness; (3) Excellent electron conductivity	(1) Highly effective; (2) Less or no corrosion; (3) No waste or disposal problems; (4) High thermo stability; (5) Easy set-up of continuous processes; (6) Great adaptability to practically all types of catalysis	(1) Irreversible adsorption or steric blockage of heavy secondary products.; (2) Impossibility of using microporosity; (3) Difficult to exploit the shape selectivity	[75, 76]
Carbon	(1) Nonmetallic; (2) Tetravalent; (3) Porous structure	(1) High mechanical strength; (2) Large surface area; (3) Excellent electron conductivity; (4) Good elasticity; (5) Thermal stability; (6) Inertness	(1) High temperature physical activation; (2) Expensive; (3) Emission of greenhouse gasses during pyrolysis	[77, 78]