new and facile synthesis of zn-mn-co ldh/polypyrrole nanocomposite as an excellent catalyst for electro-oxidation of ethanol in alkaline medium

Abstract: in recent decades, fuel cells have received much attention due to their efficiency and biocompatibility in energy conversions. these systems are highly efficient due to convenient transportation and storage, simplicity, high energy density, etc. direct alcohol fuel cells (dafcs) have received a great deal of attention due to their efficiency and environmental friendliness in portable electrical appliances. therefore, the use of alcohols such as methanol, ethanol, and ethylene glycol has many advantages. these fuels are liquid, easy to store, and have a high energy density [1]. proposed sensor for ethanol oxidation, layered double hydroxides are with the general formula [mii1−x miiix(oh)2][xq−x/q• nh2o]. the types of cations participating in their structure are bivalent and trivalent and xq− is an interlayer anion, which is theoretically a limitation for the type of anion between the two the layer is placed, does not exist [2]. and electrochemical polymerization of conducting polymers is simple and most convenient method for preparation of a film on the metal surface [3]. in this work, introduce a new zn-mn-co ldh/ polypyrrole nanocomposite as an excellent catalyst for ethanol electrooxidation in alkaline media. the above nanocomposite was synthesized by combining chemical and electrochemical methods. zn-mn-co ldh, a new synthesis, was synthesized through a novel chemical route. polypyrrole was also synthesized by electrochemical method. the synthesized product was characterized by high resolution tem, field emission scanning electron microscopy (fesem), x-ray diffraction (xrd), energy dispersive x-ray spectroscopy (edx), raman, ft-ir spectroscopy, and cyclic voltammetry techniques. this product was then used for electrocatalytic oxidation of ethanol in alkaline medium. zn-mn-co ldh/ polypyrrole/gce showed higher electrocatalytic activity than ethanol oxidation. to evaluate the performance of the above catalyst, electrochemical measurements such as cyclic voltammetry and electrochemical impedance spectroscopy were performed using a three-electrode system. the stability of zn-mn-co ldh/polypyrrole/gce catalyst was investigated using chronoamperometry technique, which showed higher stability by retention 92% of the initial current density after 6000 seconds in the long-run current-time curve. this newly developed zn-mn-co ldh/ polypyrrole nanocomposite could be a promising anodic catalyst for the use of direct ethanol fuel cells (defcs).