A universal strategy for fast, scalable, and aqueous synthesis of multicomponent palladium alloy ultrathin nanowires

Noble metal alloy nanowires (NWs) with ultrathin diameters (2–3 nm) and precisely controllable elemental compositions have attracted dramatically growing attention for (electro)catalysis. Despites numerous achievements in past two decades, noble metal alloy NWs are mostly synthesized with the traditional oil-phase methods that suffer from some undesirable drawbacks. Here, we report a general strategy for fast, scalable, and aqueous synthesis of multicomponent Pd-based alloy ultrathin NWs with an average diameter of 2.6 nm, ranging from bimetallic PdM (PdFe, PdCo, PdNi, PdCu, PdZn, PdRu, PdRh, PdAg, PdCd, PdIr, PdPt, PdAu) and binary PdS/PdP NWs, to trimetallic PdM1M2 NWs (PdAuCu, PdCoNi, PdCuZn, PdCuNi, PdAgCu, PdAuCu, PdRuAg, PdAuRu, and PdPtAu), and to tetrametallic PdM1M2M3 NWs (PdAuAgCu, PdCoCuNi, PdAuCuNi, PdPtAuCu, and PdIrPtAu). The key to the success of this aqueous synthesis is the utilization of N2H4 as the extremely strong reducing agent that directs the synchronous reduction and anisotropic nucleation growth of multicomponent Pd alloy NWs along nanoconfined columnar phase assembled with amphiphilic dioctadecyldimethylammonium chloride. As-resultant Pd-based alloy ultrathin NWs exhibit multiple structural and compositional synergies, which remarkably optimize the removal of poisoning ethoxy intermediates and thus improve electrocatalytic performance towards ethanol oxidation reaction (EOR). Among them, tetrametallic PdAuCuNi alloy ultrathin NWs hold a high EOR activity of 5.14 A mgPd−1 and a low activation energy of 13.1 kJ mol−1, both of which are much better than its counterpart catalysts alloyed with less elements. This work represents an important advance in precise aqueous synthesis of multicomponent noble metal alloy ultrathin NWs as the high-performance electrocatalysts for various targeted applications.