High-index facets of Pt-Fe nanowires induce steric effect on selective hydrogenation of acetophenone

For selective hydrogenation of substrates that contain diversified unsaturated groups, it is difficult to address the dilemma between activity and selectivity. Herein, we developed Pt-Fe nanowires with abundant high-index facets which created steric effect for improved selectivity without occupying or passivating active sites. During the selective hydrogenation of acetophenone, the turnover frequency number of Pt-Fe nanowires was 97.7 min(-1) at 70 degrees C, 5.7 times higher than that (17.2 min(-1)) of cubic counterparts. The selectivity for C = O groups over Pt-Fe nanowires reached 91.7% at a conversion of 99.3%, whereas that over nanocubes was only 60.2% at a conversion of 98.4%. The high C=O selectivity of Pt-Fe nanowires was attributed to the steric effect, where the stepped surfaces composed of high-index facets selectively adsorbed C=O bonds and inhibited the adsorption of aromatic rings. (C) 2019 Elsevier Inc. All rights reserved.