The synthesis and application of palladium nanotubes and nanoparticles on modified bentonite was studied. In the first step, an organo-bentonite was prepared by the exchange of the exchangeable Na+ cations of a homoionic Na-bentonite by cetyl pyridinium cations (CP-bentonite), especially in the range of low coverage ratios where surfactant ions are adsorbed through cation exchange with the counter ions of bentonite. At this stage, there will be a disordered liquid-like monolayer arrangement of alkyl chain within the gallery. This modified bentonite was loaded with the first generation of amidoamine hyperbranch cascade, 3,3'-(dodecylazanediyl) bis(N-(2-(2-aminoethylamino)ethyl)propanamide) (DAEP), which has a long aliphatic tail (C-12) and a hydrophilic head. The solid/liquid interfacial layer of this architecturally designed bentonite (DAEP-bentonite) was utilized as a nanoreactor for the synthesis of nanoparticles of Pd2+ and Pd-0. The structure, specific surface area, and porosity of bentonite are significantly altered by the incorporation of nanoparticles. These alterations were monitored by several techniques such as N-2 adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). The size of the palladium nanoparticles prepared in this work was in the range of 5-15 nm. Solvent free oxidation of ethyl benzene using tert-butyl hydroperoxide as an oxidant showed that the palladium nanocatalysts prepared in this work, were highly active and selective. (C) 2010 Elsevier B.V. All rights reserved.