AbstractThe crystal phase of nanomaterials is one of the key parameters determining their physicochemical properties and performance in various applications. However, it still remains a great challenge to synthesize nanomaterials with different crystal phases while maintaining the same composition, size, and morphology. Here, a facile, one‐pot, wet‐chemical method is reported to synthesize Pd₃Sn nanorods with comparable size and morphology but different crystal phases, that is, an ordered intermetallic and a disordered alloy with L1₂ and face‐centered cubic (fcc) phases, respectively. The crystal phase of the as‐synthesized Pd₃Sn nanorods is easily tuned by altering the types of tin precursors and solvents. Moreover, the approach can also be used to synthesize ternary PdCuSn nanorods with the L1₂ crystal phase. When used as electrocatalysts, the L1₂ Pd₃Sn nanorods exhibit superior electrocatalytic performance toward the ethanol oxidation reaction (EOR) compared to their fcc counterpart. Impressively, compared to the L1₂ Pd₃Sn nanorods, the ternary L1₂ PdCuSn nanorods exhibit more enhanced electrocatalytic performance toward the EOR, yielding a high mass current density up to 6.22 A mg_Pd⁻¹, which is superior to the commercial Pd/C catalyst and among the best reported Pd‐based EOR electrocatalysts.