Synthesis and Size-Selective Application of Palladium Metal Particles Intercalated in Mesopore-Size Controlled Smectite

Abstract

Mesoporous smectite-type materials (SM) were synthesized with a hydrothermal method from water glass, magnesium chloride and alkyl ammonium salt. The mesopore diameter of SM was controlled from 30 to 130 Å 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)₄Cl₂] on them and hydrogen reduction treatment. The size-selective hydrogenation of butadiene-acrylonitrile rubbers (NBR) in carbon tetrachloride was studied using palladium loaded smectite catalysts (Pd-SM). The reaction was controlled by the sizes of mesopore of Pd-SM, which determine the diffusion of polymer molecules onto the dispersed palladium particles within the pores.