A fail-proof synthetic strategy has been developed for a multiply twinned dumbbell-shaped Rh@Pt nanostructure, which exhibits a superior electrocatalytic activity for methanol oxidation reaction. The unusually high electrocatalytic activity has been attributed to the synergistic effects of crystal twinning and core-shell structure.

By understanding the structural relationship among three shape-controlled Rh nanostructures, namely, {111} nanotetrahedrons, {111} tetrahedral nanoframes, and <111> skeletal nanotetrapods, we could prepare novel hierarchical dendritic Rh nanostructures with <111> Rh arms as linkers between tetrahedral shaped nanocrystals.

Shape‐controlled Pt‐based seeds lead to completely different M/Pt (M = Ru or Rh) structures of nanobox or octapod. Unusually high catalytic activities of Pt@Ru octapod toward the oxygen evolution reaction are observed due to a core–shell effect.

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.