One- Step Electrosynthesis of New Catalysts Based on Conjugated Organic Polymers and Copper for Highly Efficient Ethanol Oxidation

Abstract

The presence of aromatic compounds rich in carbon and Azote in the backbone of conducting polymers such as polypyrrole, polyaniline, and poly-phenylenediamine improve their capacity to quench metallic particles via amine group to include them into their frameworks. Herein, a new and simple strategy based on electrochemical cascade reactions was used to prepare copper /poly (para-phenylenediamine). The catalysts were prepared by a facile one-pot synthesis via an electrochemical method in a solution containing monomer and copper in a suitable concentration using potentiostatic or galvanostatic mode. Following an in-depth review of the literature, no studies have been devoted to the preparation of catalyst by electrochemical cascade reactions. Herein, Copper oxide/ poly-phenylenediamine has been synthesized in a short time using one single reaction. For this purpose, the synthesis of our electrocatalysts was performed in one step by using one batch containing the para-phenylenediamine, and copper sulfate in the sulfuric acid solution. Two different electrochemical approaches were used for the deposition of our composite. It turns out that using galvanostatic mode leads to the formation of nanodendritic shape of copper in contrast with potentiostatic mode which leads to a spherical form. The response toward ethanol oxidation was greatly affected by the morphology of the obtained nanocomposite. Indeed, the current density obtained when using potentiostatic mode is about 26.55 mA cm-2 at 1.05 V vs Ag/AgCl. This performance is about 2.4 times higher than of the electrocatalyst prepared by galvanostatic mode (11.09 mA cm-2 at 0.85 V). The durability and long-term stability of the obtained electrocatalysts were investigated using chronoamperometry and cyclic voltammetry. The proposed method is highly promising and can provide a route for developing hybrid materials for direct alcohol fuel cell and can be exploited for other applications