Tuning composition of Pd-based bimetallic electrocatalysts of high stability and durability is of great importance in energy-related reactions. This study reports the remarkable electrocatalytic performance of carbon-supported bimetallic Pd–Cu alloy nanoparticles (NPs) towards formic acid oxidation (FAO) and oxygen reduction reaction (ORR). Among various bimetallic compositions, Pd₃Cu/C alloy NPs exhibits the best FAO and ORR activity. During FAO reaction, Pd₃Cu/C alloy NPs exhibits a peak with a current density of 28.33 mA cm⁻² and a potential of 0.2 V (vs. Ag/AgCl) which is higher than that of the other PdCu compositions and standard 20 wt% Pd/C catalyst. Meanwhile, the onset potential (−0.09 V), half-wave potential (−0.18 V), limiting current density at 1600 rpm (−4.9 mA cm⁻²) and Tafel slope (64 mV dec⁻¹) values of Pd₃Cu/C alloy NPs validate its superiority over the conventional 20 wt% Pt/C catalyst for ORR. Experimental and DFT studies have confirmed that the enhanced activity can be attributed to the electronic effect that arises after Cu alloying which causes a downshift of Pd d-band center and structural effect that produces highly dispersed NPs over the carbon matrix with high electrochemically active surface area.

具有高稳定性和耐久性的Pd基双金属电催化剂的调节组成在与能量有关的反应中非常重要。这项研究报告了碳载双金属Pd-Cu合金纳米颗粒（NPs）对甲酸氧化（FAO）和氧还原反应（ORR）的卓越电催化性能。在各种双金属成分中，Pd ₃ Cu / C合金NP表现出最佳的FAO和ORR活性。在FAO反应期间，Pd ₃ Cu / C合金NPs出现一个峰值，电流密度为28.33 mA cm ^-2电位为0.2 V（vs。Ag / AgCl），高于其他PdCu组合物和标准的20 wt％Pd / C催化剂。同时，Pd ₃ Cu的起始电势（-0.09 V），半波电势（-0.18 V），在1600 rpm（-4.9 mA cm ^-2）时的极限电流密度和Tafel斜率（64 mV dec ^-1）值。/ C合金NPs证实了其相对于ORR的传统20 wt％Pt / C催化剂的优越性。实验和DFT研究已经证实，活性的增强可归因于Cu合金化后产生的电子效应，该电子效应导致Pd d带中心的下移和结构效应，从而在碳基质上产生高度分散的NP，具有高的电化学活性表面积。