Surface-energy fine-tuned five-fold twinned nanostructures with a core-shell Pt3Ni@Rh structural motif, namely, a core-shell Pt3Ni@Rh pentagon, a core-shell Pt3Ni@Rh starfish, and a paddlewheel with a Pt3Ni crankshaft and two Rh five-fold starfish wheels, are prepared by rationally designed stepwise heteroepitaxial growth. Unusual selective hydrogenation of the phenyl ring in phthalimide is accomplished with moderately active core-shell Pt3Ni@Rh pentagons and starfish-like nanoparticles. The most active paddlewheel structure proceeds to further reduce one carbonyl group, indicating the sequential nature of phthalimide reduction by Rh nanoparticle catalysis.