Novel benzothiophene based catalyst with enhanced activity for glucose electrooxidation.

Thiophene based heterocyclic compounds plays important roles in organic chemistry due to their unexpected properties. Herein, novel benzothiophene derivatives (6A-F) are synthesized via Sonogashira coupling, iodocyclization reaction, Suzuki-Miyaura coupling and condensation reactions. After characterization of design molecules, their glucose electrooxidation activities are investigated. Electrochemical measurements are performed by cyclic voltammetry, chrono amperometry, and electrochemical impedance spectroscopy in 1 M KOH +0.5 M C 6 H 12 O 6 solution. This results show that the highest performance organic-based catalysts is obtained as 0.729 mA/cm2 (3.345 mA/mg) for the 2-(4-(2-pentylbenzo b thiophen-3-yl)benzylidene)malononitrile (6B). Furthermore, 6B catalyst is shown long term stability, the best current density value (1.151 mA cm−2), and the best transfer resistance load between organic-based catalysts. As a result, it is clear that these benzothiophene derivatives are promising organic based catalyst, an alternative to the expensive Pd and Pt based metal catalyst, for direct glucose fuel cell anode. Image 1 • Benzothiophenes are developed for glucose electrooxidation. • 2-(4-(2-pentylbenzo[b]thiophen-3-yl)benzylidene)malononitrile has superior activity. • 2-(4-(2-pentylbenzo[b]thiophen-3-yl)benzylidene)malononitrile has good stability. • Benzothiophene derivatives are promising anode catalysts for glucose fuel cells. [ABSTRACT FROM AUTHOR]