Palladium cation exchange method

Comparison of Figs. 24 and 25 shows the different degree of dispersion of palladium in the two kinds of catalysts one was prepared by the cation-exchange method and the other by the normal soaking method. 

Fig. 24. Palladium on aluminosilicate prepared by cation-exchange method. Palladium content, 1.24 meq/gm.

Fio. 26. Catalytic activity of palladium on aluminosilicate catalyst prepared by the cation-exchange method versus amount of palladium in the catalyst, the reaction being hydrogenation of benzene at 160°. 

Flo. 27. Frequency factor (A) for hydrogenation of benzene, aize of crystallite (Z),) and lattice imperfection rj) of palladium on aluminosilicate catalyst prepared by cation-exchange method versus temperatrue of calcination of the catalyst. Reduction temperature after calcination was kept constwt at 300°. 

A method for the accurate online ultratrace analysis of palladium in environmental samples (road dust and contaminated soil samples) by ICP-MS after separation of interferent cations by cation exchange chromatography was introduced by Hann and co-workers.80 Palladium was selectively adsorbed online onto a C18 microcolumn which had been reversibly loaded with a complexing agent... 

Ion-exchange separation methods are based on the retention of the palladium chloride complex on strongly basic anion-exchangers, and of the cationic ammine complex on cation-exchangers [16]. A cellulose anion-exchanger has been used to separate Pd from Pt and Ir [17], and from Ir [16]. 

---