Sub-2 nm Amorphous PdSn/C Nanocatalyst for Enhanced Ethanol Oxidation

Amorphous palladium-based catalysts exhibit unique advantages in catalytic reactions due to their large number of uncoordinated atoms and dangling bonds. However, due to the strong interaction between metal atoms, it is easy to form crystalline structures between metal atoms, and thus, the synthesis of amorphous structure is difficult. Here, the sub-2 nm amorphous PdSn nanoparticles were synthesized in one step by the liquid phase reduction method. The amorphous PdSn nanoparticles with different compositions were obtained by fine-tuning the concentration of the precursor. Compared with the commercial crystalline Pd/C catalyst, those amorphous PdSn nanoparticles with different compositions showed significantly enhanced catalytic efficiency in the ethanol electrocatalytic oxidation reaction. Among them, the PdSn0.87 nanoparticle showed the best mass activity and specific activity (3026 mA mgPd–1, 10.77 mA cm–2), which were 6.55 and 4.14 times than that of the commercial Pd/C catalyst (462 mA mgPd–1, 2.60 mA cm–2), respectively. Density functional theory (DFT) calculation shows that amorphous PdSn nanocatalysts can effectively enhance the adsorption energy of CH3CH2OH* on its surface and weaken the adsorption of CO*, thus promoting the conversion efficiency of ethanol molecules on its surface. This research paves the way for the development of highly efficient amorphous palladium-based catalysts with tailored properties for ethanol oxidation reactions.