[en] Highlights: • A selective deposition-etching approach is developed for the synthesis of Pt₄PdCu_0.4 nanoframes. • The deposition locations of Pt on Pd nanocrystals can be controlled by addition of Cu(II). • Pt₄PdCu_0.4 nanoframes show enhanced performance in oxygen reduction and formic acid oxidation. • The effects of electronic and surface structures on electrocatalytic performance are elucidated. • This work sets up a platform for simultaneously tuning surface and electronic structures. The development of bifunctional electrocatalysts for direct formic acid fuel cells requires low Pt usage, high activities in both oxygen reduction reaction (ORR) and formic acid oxidation (FAO), low CO production, and high resistance to CO. It remains a grand challenge to achieve all in a single material. Here we report a copper-assisted selective deposition-etching approach to Pt₄PdCu_0.4 nanoframes that meet all the requirements, offered by structure and electronic structure effects. Impressively, the specific activities of Pt₄PdCu_0.4 nanoframes in ORR and FAO are 9.2 times and 10.2 times higher than commercial Pt/C, respectively, with excellent durability. This work provides insights into the catalyst design that one single material synthesis sets up a platform for simultaneously tuning surface and electronic structures.