Iron-rich nanoparticle encapsulated, nitrogen doped porous carbon materials as efficient cathode electrocatalyst for microbial fuel cells

Abstract

Developing efficient, readily available, and sustainable electrocatalysts for oxygen reduction reaction (ORR) in neutral medium is of great importance to practical applications of microbial fuel cells (MFCs). Herein, a porous nitrogen-doped carbon material with encapsulated Fe-based nanoparticles (Fe-N x /C) has been developed and utilized as an efficient ORR catalyst in MFCs. The material was obtained through pyrolysis of a highly porous organic polymer containing iron(II) porphyrins. The characterizations of morphology, crystalline structure and elemental composition reveal that Fe-N x /C consists of well-dispersed Fe-based nanoparticles coated by Ndoped graphitic carbon layer. ORR catalytic performance of Fe-N x /C has been evaluated through cyclic voltammetry and rotating ring-disk electrode measurements, and its application as a cathode electrocatalyst in an air-cathode single-chamber MFC has been investigated. Fe-N x /C exhibits comparable or better performance in MFCs than 20% Pt/C, displaying higher cell voltage (601 mV vs. 591 mV), maximum power density (1227 mW m-2 vs. 1031 mW m-2) and Coulombic efficiency (50% vs. 31%). These findings indicate that Fe-N x /C is more tolerant and durable than Pt/C in a system with bacteria metabolism and thus holds great potential for practical MFC

Air Breathing Cathodes for Microbial Fuel Cell using Mn-, Fe-, Co- and Ni-containing Platinum Group Metal-free Catalysts

“…Using the rotating ring disk electrode (RRDE) technique, it was recently shown that oxygen is reduced via a 2e − mechanism on carbon black and activated carbon [23], [24], where as a 4e − pathway is dominant for Pt [24] and Fe-based catalyst [25], [26]. In order to enhance the ORR kinetics, usually three different pathways can be selected for integration of catalysts into the cathode layer.…”

Bimetallic platinum group metal-free catalysts for high power generating microbial fuel cells

“…Usually, the earth abundant transitional metal is atomically dispersed within a carbonaceous substrate rich in nitrogen. Several PGM-free catalysts were presented in literature, and particularly, catalysts based on iron [67], [68], [69], [70], [71], [72], [73], [74], [75], cobalt [76], [77], [78], [79], manganese [80], [81], [82], nickel [83], [84], etc [85], [86] have been investigated as cathode catalysts in the ORR reaction. Among these earth abundant metals, iron and cobalt are particularly alluring due to their higher performances compared to Mn, Ni and al [1], [87], [88].…”

Integration of Platinum Group Metal‐Free Catalysts and Bilirubin Oxidase into a Hybrid Material for Oxygen Reduction: Interplay of Chemistry and Morphology

“…[11,12] Nevertheless,t he oxygen reduction reaction (ORR) has challenges neededt oo vercome, such as high overpotentials and slow reactionk inetics. [16,[26][27][28][29][30] Those catalysts were also used to complete ORR in biological systems( e.g.,m icrobial FC, MFC) [14,[31][32][33][34][35][36][37][38][39][40] at mild operational conditions, neutralp H, and room temperature. [9,[13][14][15] Looking to solve these two problems, namely i) slow ORR kinetics and ii)high price of the commonc atalysts materials, several groups have taken on the task of developing alternative catalysts to replacep latinum at the cathode electrode.…”