one-pot synthesis of chromic oxide and zinc oxide as a new for oxygen reduction reaction

Fuel cells are electrochemical energy instruments that convert chemical energy of a fuel and oxygen to electricity. the use of metal nanoparticles and their composites offers many attractive avenues for oxygen reduction reactions (orr)[1]. particularly, noble metals like platinum [2], palladium [3], and ruthenium [4] have been extensively reported for electrocatalytic applications [1]. however, their widespread applications are severely hindered by the element scarcity, expensiveness, and poor long-term stability[5]. therefore, it is imperative to develop highly active orr electrocatalysts with earth-abundant and cost-effective components[5]. among all reported candidates, non-precious metal oxides like, zno and cr2o3 materials are always constructive owing to their chemically stable, less expensive and environment friendly benign. as a result of, to synthesis transition metal materials in a very simple reaction conditions and use for orr alkaline media has been conducted. the catalyst has been synthesized and prepared using the sol-gel method.in this regards, x-ray diffractometer (xrd) and scanning electron microscopy (sem) technique are used to investigate the crystallite size and the surface morphologies respectively. the electrochemical characteristics of the zno/cr2o3 catalysts have been investigated by cyclic voltammetry (cv), linner sweep voltammetry (lsv) and current-potential measurements, electrochemical impedance spectroscopy (eis) in oxygen saturated 0.1 m koh. fig.1 shows the cv of the prepared catalyst and examined in presence and absence of n2 and o2 in alkaline media. the onset potential of the catalyst is calculated ( 0.73 v vs. rhe).fig.2 shows the lsv curves at various rotation rates for zno/cr2o3 catalysts. the toefl slope and the number of transferred electrons are calculated.