Composition- and size-engineering of porous PdAg alloy for high-performance ethanol electrooxidation

Control over the architecture, elemental distribution, composition and size of metal bimetallic nanocrystals can effectively manipulate and improve their catalytic performances. Herein, we construct the PdAg bimetallic nanostructures with Pd and Ag overlapped distribution to form an alloy feature via an easy operation method at ambient conditions. The prepared PdAg alloy nanocrystals are porous that composed of numerous branches on their surfaces with a composition of Pd₁₀₀Ag₀ to Pd₆₁Ag₃₉ and a size ranging from 16.4 ± 1.8 to 45.0 ± 1.5 nm. Impressively, after detail size- and composition-dependent electrocatalytic evaluations toward ethanol oxidation in alkaline, the Pd₆₇Ag₃₃ nanocrystals with a size of 27.0 ± 1.2 nm exhibit the highest mass activity (1394.49 mA mg⁻¹), which is 4.77 and 5.46 times of porous Pd NCs and commercial Pd/C, respectively. Besides, the durability during electrocatalytic tests were also highly improved. The excellent electrocatalytic property is ascribed to the synergistic effect between Pd and Ag, the high surface area brought by the porous and branched morphology, as well as the proper size the alloy electrocatalysts provided.