This paper shows that the combination of an O-2 saturated acidic fluid setup (O-2-setup) and a composite of Pd nanoparticles supported on multiwalled-carbon nanotubes (Pd/MWCNTs) as anode catalyst material, results in the improvement of microfluidic fuel cell performance. Microfluidic fuel cells were constructed and evaluated at low HCOOH concentrations (0.1 and 0.5 M) using Pd/V XC-72 and Pd/MWCNTs as anode and Pt/V XC-72 as cathode electrode materials, respectively. The results show a higher power density (2.9 mW cm(-2)) for this cell when compared to the value reported in the literature that considers a commercial Pd/V XC-72 and 3.3 mW cm(-2) using a Pd/MWCNTs with a 50% less Pd loading than that commercial Pd/V XC-72. (C) 2009 Elsevier B.V. All rights reserved.