Electron-Enriched Pd Nanoparticles for Selective Hydrogenation of Halonitrobenzenes to Haloanilines

Abstract

Selective hydrogenation of halonitrobenzenes into haloanilines represents a green process to replace the environmentally unfriendly non-catalytic chemical reduction process in industry. However, this transformation often suffers from serious dehalogenation due to the easy break of carbon-halogen bonds on metal surfaces. Modulations of the electronic structure of the supported Pd nanoparticles on Lewis-basic layered double hydroxides have been demonstrated to promote catalytic activity and selectivity for hydrogenation of halonitrobenzenes into haloanilines. Mechanism studies suggest that Pd with the enhanced electron density not only improves the capability for hydrogen activation, but also generates the partially negative-charged hydrogen species to suppress the electrophilic attack on the carbon-halogen bond and avoid the dehalogenation.