Ultrafine IrMnO_x Nanocluster Decorated Amorphous PdS Nanowires as Efficient Electrocatalysts for High C1 Selectivity in the Alkaline Ethanol Oxidation Reaction

As a novel electrochemical energy conversion device, direct ethanol fuel cells are currently encountering two significant challenges: CO poisoning and the difficulty of C–C bond cleavage in ethanol. In this work, an amorphous PdS nanowires/ultrafine IrMnO x bimetallic oxides (denoted as a-PdS/IrMnO x NWs) catalyst with abundant oxide/metal (crystalline/amorphous) inverse heterogeneous interfaces was synthesized via a hydrothermal process succeeded by a nonthermal air-plasma treatment. This unique interfacial electronic structure along with the incorporation of oxyphilic metal has resulted in a significant enhancement in the electrocatalytic performance of a-PdS/IrMnO x NWs toward the ethanol oxidation reaction, achieving current densities of 12.45 mA·cm –2 and 3.68 A·mg Pd –1 . Moreover, the C1 pathway selectivity for ethanol oxidation has been elevated to 47%, exceeding that of other as-prepared Pd-based counterparts and commercial Pd/C catalysts. Density functional theory calculations have validated the findings that the decoration of IrMn species onto the amorphous PdS surface has induced a charge redistribution in the interface region. The redistribution of surface charges on the a-PdS/IrMnO x NWs catalyst results in a significant decrease in the activation energy required for C–C bond cleavage and a notable weakening of the CO binding strength at the Pd active sites. Consequently, it enhanced both the EOR C1 pathway selectivity and CO poisoning resistance to the a-PdS/IrMnO x NWs catalyst.