Design of 2-(4-(2-pentyllbenzo[b]thiophen-3-yl)benzylidene)malononitrile based remarkable organic catalyst towards hydrazine electrooxidation

Abstract Herein, 2-(4-(2-pentyllbenzo[b]thiophen-3-yl)benzylidene)malononitrile (6B) is synthesized by using coupling reactions, electrophilic cyclization reactions, and condensation reactions. Then, these materials are employed as anode catalysts for hydrazine electrooxidation reactions with electrochemical methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in 1 M KOH+0.5 M N2H4 solution on different benzothiophene derivates. 6B catalyst exhibits the best catalytic activity in hydrazine electrooxidation reaction with 3.22 mA cm-2 (16.72 mA mg-1 6B) value. Thus, for the electrodes obtained from 6B, the electrode preparation stage is optimized by the response surface methodology (RSM) and the hydrazine electrooxidation current under optimum conditions is found as 4.95 mA cm-2. EIS results reveal that 6B modified electrode has the lowest charge transfer resistance. In conclusion, 6B catalyst could be used as anode catalysts in hydrazine fuel cells instead of expensive catalysts such as Pt, Pd, and Au.