Fuel blends: Enhanced electro-oxidation of formic acid in its blend with methanol at platinum nanoparticles modified glassy carbon electrodes

The current study addresses, for the first time, the enhanced direct electro-oxidation of formic acid (FA) at platinum-nanoparticles modified glassy carbon (nano-Pt/GC) electrode in the presence of methanol (Me0H) as a blending fuel. This enhancement is probed by: (i) the increase of the direct oxidation current of FA to CO2 (I-p(d), dehydrogenation pathway), (ii) suppressing the dehydration pathway (I-p(ind), producing the poisoning intermediate CO) and (iii) a favorable negative shift of the onset potential of I-p(d) with increasing the mole fraction of MeOH in the blend. Furthermore, the charge of the direct FA oxidation in 0.3 M FA + 0.3 M MeOH blend is by 14 and 21 times higher than that observed for 0.3 M FA and 0.3 M MeOH, respectively. MeOH is believed to adsorb at the Pt surface sites and thus disfavor the "nonfaradaic" dissociation of FA (which produces the poisoning CO intermediate), i.e., MeOH induces a high CO tolerance of the Pt catalyst. The enhanced oxidation activity indicates that FA/MeOH blend is a promising fuel system. (C) 2015 Elsevier B.V. All rights reserved.