Facile synthesis of mixed valance manganese oxide hydroxide supported palladium nanostructures - Active electrocatalysts for polyhydric alcohol oxidation and its poisonous management

In this communication, nanostructured palladium (Pd) nanoparticles grafted in a mixed valance manganese oxide material, such as manganese (oxy) hydroxide and manganese oxide (MnOOH and Mn₃O₄; MMOH) nanorods, were developed by a simple two-step process and explored its catalytic activity towards polyhydric alcohol (Xylitol) electro-oxidation in alkaline medium. The prepared nanocatalyst was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and electrochemical methods. The XRD and XPS analysis show that the prepared MMOH is mixed valance (Mn³⁺/Mn⁴⁺), and the microscopic results confirm the Pd nanoparticles uniformly coated on the MMOH. The cyclic voltammetric studies reveal that the MMOH/Pd catalyst-modified electrode exhibited improved electrocatalytic activity for Xylitol electrooxidation compared to C/Pd. The intermediates formed during the electro-oxidation reactions were removed by increasing the forward scanning potential from +0.2 V to +0.8 V. The catalytic involvement of MMOH nanorods in poison management is discussed in detail. This study demonstrates the MMOH acts as a superior catalytic supporting material for noble metal catalyst towards polyalcohol electro-oxidation.