Nanostructuring carbon supports for optimal electrode performance in biofuel cells and hybrid fuel cells

Dominika Majdecka,Renata Bilewicz

doi:10.1007/s10008-015-2969-6

Abstract

The efficiencies of dioxygen reduction on common carbonaceous materials were compared using voltammetry and fuel cell measurements. Carbon paper (CP), carbon fibre (CF) or carbon cloth (CC) conducting supports were covered under water pump pressure with multiwalled carbon nanotubes (MWCNTs) to increase the working surface of the electrode, improve connectivity with enzyme molecules and provide direct electron transfer. Laccase was the biocathode catalyst catalyzing 4-electron reduction of oxygen to water on the nanostructured electrode. CP carbon paper was selected as the favourable electrode substrate, since it provided best durability holding firmly the carbon nanotubes together with the enzyme at the electrode surface. Zinc disc or fructose dehydrogenase was used as anode in the hybrid fuel cell and biofuel cell, respectively. The characteristics under externally applied resistances and potential-time dependencies under flowing solution conditions were evaluated. The hybrid fuel cell based on Zn anode and CP supported laccase cathode gave the best results in terms of power and open circuit potential (OCP). The full biofuel cell based on laccase and fructose dehydrogenase shows lower OCP but the power–time dependencies were similar to those of the hybrid biofuel cell. The nanostructured surfaces show good supercapacitor properties due to the presence of carbon nanotubes at the electrode surface. The fuel cells undergo self-charging/discharging and, therefore, can be conveniently employed in pulsed-work regime to power external devices.

Highlights

There have been several approaches in the recent years to substitute costly platinum electrodes in the fuel cells with non-precious metal catalysts and carbon materials such as graphite electrodes or carbon electrodes covered with carbon nanoparticles or carbon nanotubes
Several transition M-N4 metal compounds have been proposed as catalytic materials for the oxygen reduction reaction (ORR)
Zinc disc covered with zinc phosphate was used as the anode in the Zn hybrid fuel cell and fructose dehydrogenase (FDH) adsorbed on multiwalled carbon nanotubes (MWCNTs) – nanostructured support was the anode in the full biofuel cell

Summary

Introduction

There have been several approaches in the recent years to substitute costly platinum electrodes in the fuel cells with non-precious metal catalysts and carbon materials such as graphite electrodes or carbon electrodes covered with carbon nanoparticles or carbon nanotubes. We compare the performances of various carbon substrates covered with multiwalled carbon nanotubes and laccase in the catalytic reduction of oxygen.

Results

Conclusion