Developing highly efficient bifunctional cathode and anode electrocatalysts is very important for the large-scale application of direct formic acid fuel cells. However, the high-cost and poor CO-tolerance ability of the most commonly used Pt greatly block this process. To increase the utilization efficiency and extend bifunctional properties of precious Pt, herein, coral-like Pt₃Ag nanocrystals are developed as an excellent bifunctional electrocatalyst through a facile one-pot solvothermal method. The formation mechanism of Pt₃Ag nanocorals has been elaborated well via a series of control experiments. It is proved that 1-naphthol serving as a guiding surfactant plays a key role in the formation of high-quality nanocorals. Thanks to the unique coral-like structure and alloy effects, the developed Pt₃Ag nanocorals present significantly enhanced electrocatalytic properties (including activity, stability and CO-tolerance ability) towards both the cathodic oxygen reduction and anodic formic acid oxidation, as compared with those of commercial Pt black and Pt-based nanoparticles. The present synthetic method can also be extended to fabricate other bimetallic electrocatalysts with unique morphology and structure.

A novel carbon-supported cyanogel (C@cyanogel)-derived strategy is used to synthesize an intermetallic Pd₃Fe/C compound of the desired ordered Pd₃Fe phase with a small particle size. The novelty of this work lies in using carbon-supported K₂Pd^IICl₄/K₄Fe^II(CN)₆ cyanogel as a reaction precursor, generated through the substitution of two chloride ligands by the nitrogen ends of the cyanide ligands on the metal center. The inherent nature of cyanogels can effectively suppress the movement of Pd⁰ and Fe⁰ nuclei in the crystal, benefiting the formation of the intermetallic, which is otherwise challenging via traditional synthesis techniques. The ordered Pd₃Fe/C catalyst exhibits excellent catalytic activity and good cycle stability for the formic acid oxidation (FAO) reaction relative to the properties of disordered Pd₃Fe/C and commercial Pd/C catalysts, demonstrating that the ordered Pd₃Fe/C is a promising replacement for commercial Pd-based catalysts. The outstanding performance can be ascribed to the full isolation of active sites in the ordered Pd₃Fe structure and the modified electronic structure of the active components. This work provides an effective and novel route to obtain Pd-based intermetallic compounds with potential applications in a wide range of electrocatalysis.