Perspective of Use of Pd/rGO in a Direct Urea Microfluidic Fuel Cell

Abstract

The urine/urea oxidation reaction through catalysts with a higher performance in direct urea microfluidic fuel cells (DUµFC) is a promising method for power generation due to the large amount of human and animal urine containing 2–2.5 wt% urea. This paper presents a study that used urea as fuel in a DUµFC in the presence of palladium supported by reduced graphene oxide (rGO) for power generation. Some parameters, such as urea, KOH and H2SO4 concentration and flux rate, among others, are optimized in order to carry out the evaluation of urine samples as fuel in an air-breathing microfluidic fuel cell. The results show that the Pd/rGo catalyst mixed with Nafion® in the anodic compartment is dispersed and attached to the paper fibers, generating electrical contact and giving rise to the reactions of interest. In addition, XRD analysis confirmed the successful deposition of Pd and rGo on the substrate. These electrochemical results are promising, since, despite the decrease in the general performance of the DUµFC under ideal conditions with respect to normal cells, the generation of energy from urine was demonstrated.