(179b) Facile Synthesis of Palladium Hydride Nanocrystals with Greatly Enhanced Activity and Durability Toward Formic Acid Oxidation

We report a synthetic method to obtain palladium hydride (PdHx) icosahedra (x = 0–0.7) showing superior catalytic performance toward formic acid oxidation (FAO). We first demonstrate that the phase transformation from Pd to PdHx can be significantly facilitated by achieving a “single-phase pathway” when the particle size is reduced down to 6 nm. The “single-phase pathway” can then be leveraged to obtain PdHx icosahedra (12 nm) with any x in the range of 0–0.7. Meanwhile, the phase transformation is accelerated due to the tensile strain in Pd icosahedra. The chemical potential for hydrogen atoms is greatly decreased in the Pd lattice under tensile strain, making it hard for the absorbed hydrogen to escape from PdHx (x=0–0.7) icosahedra at elevated temperatures or during FAO.