Typical Additives and Solution Stabilizers

Nitrilo triacetic acid (NTA), ethylene diamine tetraacetic acid (EDTA), ethylene diamine (C2H8N2), and citric acid (2-hydroxypropane-l,2,3-tricarboxylic acid) are the most frequently used organic additives. A clear aqueous impregnation solution can be prepared by  

Most of the solutions used are aqueous - there are only a few examples of preparations using organic solvents. For instance, magnesia-supported Ni-Mo catalysts can be prepared by nonaqueous impregnation using dimethyl sulfoxide and methanol as solvents [50]. Dimethyl formamide was used as a solvent for the impregnation of phosphomolybdates on y-Al203 [51]. 

Depending on the metal concentrations and the solution stabilizers applied, the impregnation solutions can contain a wide range of species such as 

Pore-Volume Impregnation versus Dipping/Equilibrium Impregnation of Compacted Support Particles 

Methods such as dipping/equilibrium impregnation are only used to a limited extent. When dipping, the AI2O3 support is placed in a stainless steel basket and dipped into an aqueous impregnating solution, for example, prepared by 

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