Robust Ir Doping of Sub-one-nanometer PtMn Nanowires: Highly Active and Stable Catalysts for Alcohols Electrooxidation
One-dimensional (1D) Pt-based nanowires (NWs) materials are serving as efficient catalysts in alcohol electrocatalysis. However, precise tailoring their size towards sub-one-nanometer scale has been verified effective methods for enhancing electrocatalytic properties, which is rarely studied. In this work, we have developed a one-pot simple yet efficient method for synthesizing a kind of sub-one-nanometer tiny Ir-doped PtMn NWs. The prepared PtMnIr NWs exhibit the ultrathin structure with the mean diameter of around only 0.97 nm (about 3-5 atomic thickness), which display large surface active areas and promote the superficial Pt atom utilization. With the robust tiny Ir incorporation, the composition-optimized Pt74Mn21Ir5 NWs show the enhanced mass activity, which is 1.51 and 1.53 times higher than non-Ir-doped Pt79Mn21 NWs for acidic ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR). Moreover, benefiting from atom-level ultrathin size and well-tuned ligand effect from Ir to PtMn, the EOR/MOR mass activities of sub-nanometric Pt74Mn21Ir5 NWs are 3.99 and 3.98-fold higher than Pt/C NWs. More importantly, after EOR and MOR successive CV tests, the Ir-doped PtMn NWs could still maintain 85.6% and 73.4% of initial mass activity, which is much better than Pt79Mn21 NWs, Pt NWs, and Pt/C catalysts. This work could be extended to engineering other advanced materials with super sub-one-nanometer structures, which is beneficial to largely improve the catalytic performance.