A pyridine-Fe gel with an ultralow-loading Pt derivative as ORR catalyst in microbial fuel cells with long-term stability and high output voltage.

A low-cost and high-efficiency oxygen reduction reaction (ORR) catalyst was fabricated using a pyridine-Fe gel with ultralow-loading of Pt nanoparticles and subsequently applied to air-cathode microbial fuel cells (MFCs). This novel catalyst (N 3 /Fe/C-Pt) exhibited excellent electrocatalytic activity with a positive onset potential of 0.19 V (vs Ag/AgCl) and half-wave potential of 0.03 V (vs Ag/AgCl), which is comparable to commercial Pt C catalysts. More importantly, N 3 /Fe/C-Pt shows remarkable oxygen reduction activity in MFCs with a distinct output voltage (568 mV) and power density (504 mW m−2) for 400 h when it is fed with a culture medium containing 5 g L−1 sucrose in the phosphate buffer solution. This strategy, incorporating Pt nanoparticles uniformly into a conductive gel demonstrates significance for broadening the development and research of gel-based catalysts for applications in batteries. A low-cost and high-efficient oxygen reduction reaction catalyst (N 3 /Fe/C-Pt) is applied in an air-cathode microbial fuel cell, which is compared with the commercial Pt/C catalysts. Unlabelled Image • Air cathode MFCs showed high output voltage at 0.568 V for 400 h. • The pyridine-Fe gel showed large specific surface area and abundant ORR sites. • N 3 /Fe/C-Pt catalysts exhibited excellent electrocatalytic activity. [ABSTRACT FROM AUTHOR]