Phosphorous incorporation into palladium tin nanoparticles for the electrocatalytic formate oxidation reaction.

• Colloidal palladium tin nanoparticles containing phosphorous are produced. • PdSnP/C catalysts show record activity towards the formate oxidation reaction. • DFT calculations show phosphorus promotes FOR through an electronic mechanism. The deployment of direct formate fuel cells (DFFCs) relies on the development of active and stable catalysts for the formate oxidation reaction (FOR). Palladium, providing effective full oxidation of formate to CO 2 , has been widely used as FOR catalyst, but it suffers from low stability, moderate activity, and high cost. Herein, we detail a colloidal synthesis route for the incorporation of P on Pd 2 Sn nanoparticles. These nanoparticles are dispersed on carbon black and the obtained composite is used as electrocatalytic material for the FOR. The Pd 2 Sn 0.8 P-based electrodes present outstanding catalytic activities with record mass current densities up to 10.0 A mg Pd -1, well above those of Pd 1.6 Sn/C reference electrode. These high current densities are further enhanced by increasing the temperature from 25 °C to 40 °C. The Pd 2 Sn 0.8 P electrode also allows for slowing down the rapid current decay that generally happens during operation and can be rapidly re-activated through potential cycling. The excellent catalytic performance obtained is rationalized using density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]