Gas-phase synthesis of morphology-controlled Pt nanoparticles and their impact on cinnamaldehyde hydrogenation†
Abstract
Gas-phase synthesis of morphology-controlled Pt nanoparticles (PtNPs) is conducted with carbon monoxide as a protective agent. Depending on the preparation temperature, Pt nanocubes with Pt{100} or cuboctahedra with Pt{111} and Pt{100} facets are formed by reducing Pt/C and Pt/SiO2 under a CO/H2 flow, although Pt nanospheres are formed under a H2 flow in the absence of CO. The influence of the Pt nanoparticle morphology on cinnamaldehyde hydrogenation is explored by comparing the hydrogenation performances of Pt nanocubes, cuboctahedrons, and spheres with various particle sizes. The hydrogenation activity and selectivity toward cinnamyl alcohol are enhanced in the order Pt nanocuboctahedra > Pt nanocubes > Pt nanospheres; thus, Pt{111} facets > Pt{100} facets > rounded (stepped) surface with respect to the surface structure.