Mesoporous palladium-boron alloy nanospheres
Noble-metal-metalloid binary palladium-boron (Pd-B) nanoalloys are interesting because the smaller boron atoms enlarge the Pd-Pd interlattice spacings and modify the binding energy barriers of catalytic intermediates. Nanostructured morphologies of binary Pd-B nanoalloys are an emerging class of (electro)catalysts that leverage these properties to enhance performance in chemical reactions. We here describe the first synthesis of binary Pd-B alloy mesoporous nanospheres (MNSs) and evaluate their electrocatalytic performance in the ethanol oxidation reaction (EOR). This method uses dimethylamine borane and boric acid as both the reducing agents and boron sources, and amphiphilic dioctadecyldimethylammonium chloride (DODAC) as the surfactant template. The cylinder mesophase of DODAC with the strong hydrophobic nature inhibits the mobility of Pd metal precursor, and nanoconfines the crystalline growth to form binary Pd-B MNSs with three-dimensional (3D)-dendritic center-radial mesochannels. We demonstrate the synthetic protocol can be adopted to rationally tune the diameters of the Pd-B MNSs from 30 nm to 120 nm without destroying mesoporous structure and elemental compositions. The Pd-B MNSs combine high surface area with favorable electrocatalytic surface properties to generate exceptional electrocatalytic performance for the EOR in alkaline condition, illustrating the promise of this method as a platform to yield highly efficient electrocatalysts.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry A HOT Papers