PdMoW trimetallene facilitates the electrooxidation of ethanol in alkaline electrolyte with high efficiency and C2 selectivity.

Against the backdrop of global carbon neutrality target driving the transformation of energy structure, alcohol fuel cells (AFCs) show great application potential; However, the sluggish kinetics of their anodic alcohol oxidation reaction hinders the commercialization of AFCs. Metallene is a novel 2D material with potential application prospect in the field of electrocatalysis. In this paper, Pd1Mo1W trimetallene has been successfully produced by a one-pot wet-chemical method, which displays a unique two-dimensional curved ultrathin graphene structure. Mo and W atoms were doped into the lattice of Pd atoms to form a Pd1Mo1W ternary alloy, which resulted in the lattice spacing of Pd being enlarged to 0.229 nm and the d-band center of Pd being reduced by 1.10 eV. Therefore, Pd1Mo1W trimetallene demonstrated excellent electrocatalytic performance for the oxidation of ethanol and ethylene glycol in alkaline electrolyte. Especially for the ethanol oxidation reaction (EOR), Pd1Mo1W trimetallene exhibited excellent mass activity (7.55 A mgPd-1) and intrinsic activity (13.5 mA cm-2), low apparent activation energy (41.8 kJ mol-1), and outstanding CO anti-poisoning ability. According to the nuclear magnetic resonance, in-situ fourier transform infrared reflection spectra, and density-functional theory calculations, it is revealed that the Pd1Mo1W trimetallene with high surface area formed by Mo-doping reduces the d-band center of the active site, facilitates the adsorption of OH species, and enhances the tolerance of CO-poisoned intermediate, so that EOR can be carried out through C1 and C2 pathways at a lower potential. Compared to the electrocatalytic EOR system, the photocurrent density of Pd1Mo1W trimetallene under xenon lamp irradiation increased by 1.73 times, which was mainly attributed to the electron resonance effect generated by Mo and W elements to promote the electron transfer to Pd. The excellent electrocatalytic ethanol and ethylene glycol performance of Pd1Mo1W demonstrates the great application potential of metallene for electrocatalysis.