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.