MCM-41-Supported Organometallic-Derived Nanopalladium as a Selective Hydrogenation Catalyst

Palladium nanocatalysts have been prepared by anchoring (η 3 -C 3 H 5 ) 2 Pd 2 Cl 2 onto diamine-functionalized MCM-41 supports followed by reaction with hydrogen under catalytic conditions. The catalyst precursor and used catalyst have been studied by solid-state NMR ( 13 C, 29 Si), XPS, and TEM. The organometallic-derived catalyst exhibits the best performance (activity and selectivity) to date toward the selective hydrogenation of industrially relevant o - and m -chloronitrobenzene to the corresponding chloroaniline derivatives and is distinctly superior to 5% Pd/C. Grazing angle XPS studies reveal that conversion of the tethered molecular species to the nanoparticles of palladium produces a core−shell nanostructure.