Palladium tetraammine

Palladium, polymethylenebis(diphenylphosphine)-bis(thiocyanato)-linkage isomers, 1, 185 Palladium, tetraammine-tetrachloropalladate history, 1, 2 Palladium, tetrachloro-crystal structure, 1, 16 Palladium, tris(dinitrogen)-synthesis, 1,28 Palladium complexes a,(5-dione dioximates electrical properties, 6, 143 acetylacetone hydrolysis, 2,379 alkylperoxo... 

Palladium, polymethylenebis(diphenylphosphine)-bis(thiocyanato)-linkage isomers, 185 Palladium, tetraammine-tetrachloropalladate history, 2... 

The most straightforward case of electrostatic adsorption occurs with the most stable metal complexes such as platinum or palladium tetraammines, [(NH3)4Pt]+ and [(NH3)4Pd]+ or PTA and PdTAs, respectively. Over the wide pH and concentration ranges that can be employed during syntheses from the lab to the industrial scale, the relatively strongly bound ammine ligands of these coordination complexes remain intact. This has been most directly confirmed in the case of Pt by extended X-ray absorption fine structure (EXAFS) analysis of PTA solutions and adsorbed species [23], and for PdTAs less directly by XPS [24]. 

Pdll deposition was effected by incipient wetness impregnation of either the M0/AI2O3 precursors or the bare support with aqueous solutions of either [Pd(H20)4]2+ nitrate (prepared by dilution of a commercial solution immediately before use to avoid Pd hydrolysis - procedure denoted PdN) or of [Pd(NH3)4]2+ chloride (PdA, for Palladium tetraAmmine). Samples mentioned in this study... 

Pd-Mo/yAl203 from palladium tetraammine existence of ultra dispersed Pd ... 

Palladium has been successfully plated from baths after introduction as the tetraammine-palladium(II) cation [Pd(NH3)4]2+, as the nitrite, nitrate or chloride salts. In the latter case, dichlorodiamminepalladium(II) is added to a bath containing ammonium salts (chloride, sulfate and carbonate) and free ammonia. Baths based on [Pd(N02)4]2 /NaCl and [PdCl4]2 /NH4Cl have also been used. 

Palladium acetate in aqueous ammonia (pH= 11) was used to ion exchange Pd (2 % w/w) onto the pre-purified, calcined support. After air drying in stove, the Pd tetraammine complex was decomposed to the diaanunine one at 423K. Part of the stock was used to prepare a first set (S Series) of Ca promoted catalysts where maximum Ca-Pd interaction was expected a second part was H2 reduced instead (723K 2 K/min) to minimize the said interaction (R Series). Different amounts of Ca(AcO)2 were added by incipient wetness, in vacuo, to aliquots of both stocks (Ca/Pd= 0.1, 0.2, 0.5, 1.0, and 2.0 at/at) and then water was sublimated. Both series were calcined at 673K ( 2 K/min) in dry, C02-fi ee air and then reduced in H2 at 723K. 

The essential importance during stage of impregnation of SAPO material with precious metal is an origin of the latter. Usually tetraammine complexes of Pd or Pt are used for that purpose. Tetraammine complexes have definite composition and their water solution have practically neutral pH value. For the case of palladium loading we have checked the influence of another form of palladium, namely palladium dichloride, water solution of which possesses slightly acidic reaction. Catalytic data are presented in Table 4. 

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