Spatial Location and Microenvironment Engineering of Pt-CeO2Nanoreactors for Selective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol

Abstract

More than 25% of chemical transformations involve at least one hydrogenation step. Selective hydrogenation of unsaturated aldehydes is an essential process in the industrial production of pesticides and pharmaceutical synthesis. Since C═C hydrogenation with lower bond energy is thermodynamically favored over C═O hydrogenation, the selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) is relatively challenging. Herein, we report a series of Pt-CeO2 nanoreactors with different spatial locations and microenvironments of Pt nanoparticles (NPs) on hollow CeO2 that are active for the selective hydrogenation of CAL to COL. We show the effects of active metal spatial location, microenvironment, metal-support interactions, and Fe doping on the activity and selectivity within Pt-CeO2 nanoreactors. Pt@Fe-CeO2 shows excellent catalytic performance with an 88.9% selectivity for COL at a CAL conversion of 97.2%. The variations of the electronic and crystal structure after Fe doping, simultaneously, and the linear adsorption of CAL on the CeO2 hollow structure contribute to the high performance of selective hydrogenation to COL. Our findings might shed light on the rational design of the nanoreactors for catalytic organic transformations with desired selectivity.