Synthesis and size-selective application of palladium metal particles intercalated in mesopore-size controlled smectite

Mesoporous smectite-type materials (SM) were synthesized with a hydrotherma l method from water glass, magnesium chloride and alkyl ammonium salt. The mesopore diameter of SM was controlled from 30 to 130 Angstrom by changing the reaction temperature, pH and the template materials during hydrothermal treatment. Palladium metal particles were intercalated in the mesopores of SM with an ion-exchanging of [Pd(NH3)(4)Cl-2] on them and hydrogen reducti on treatment. The size-selective hydrogenation of butadiene-acrylonitrile r ubbers (NBR) in carbon tetrachloride was studied using palladium loaded sme ctite catalysts (Pd-SM). The reaction was controlled by the sizes of mesopo re of Pd-SM, which determine the diffusion of polymer molecules onto the di spersed palladium particles within the pores.