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

Abstract

M1-M2-N-C bimetallic catalysts with M1 as Fe and Co and M2 as Fe, Co, Ni and Mn were synthesized and investigated as cathode catalysts for oxygen reduction reaction (ORR). The catalysts were prepared by Sacrificial Support Method in which silica was the template and aminoantipyrine (AAPyr) was the organic precursor. The electro-catalytic properties of these catalysts were investigated by using rotating ring disk (RRDE) electrode setup in neutral electrolyte. Fe-Mn-AAPyr outperformed Fe-AAPyr that showed higher performances compared to Fe-Co-AAPyr and Fe-Ni-AAPyr in terms of half-wave potential. In parallel, Fe-Co-AAPyr, Co-Mn-AAPyr and Co-Ni-AAPyr outperformed Co-AAPyr. The presence of Co within the catalyst contributed to high peroxide production not desired for efficient ORR. The catalytic capability of the catalysts integrated in air-breathing cathode was also verified. It was found that Co-based catalysts showed an improvement in performance by the addition of second metal compared to simple Co- AAPyr. Fe-based bimetallic materials didn't show improvement compared to Fe-AAPyr with the exception of Fe-Mn-AAPyr catalyst that had the highest performance recorded in this study with maximum power density of 221.8 ± 6.6 μWcm−2. Activated carbon (AC) was used as control and had the lowest performances in RRDE and achieved only 95.6 ± 5.8 μWcm−2 when tested in MFC.

Boosting Microbial Fuel Cell Performance by Combining with an External Supercapacitor: An Electrochemical Study

“…[26] Platinum is a very active catalyst, but it is extremely expensive and sensible to poisoning in the presence of anions. [27][28][29][30] Carbonaceous-based materials [31][32][33] and transition metal-containing catalysts [34][35][36][37] have replaced platinum successfully. The addition of transition metals and especially FeÀ NÀ C active sites has improved significantly the performance almost doubling the MFCs output.…”

Electrospinning‐on‐Electrode Assembly for Air‐Cathodes in Microbial Fuel Cells

“…Alternative materials must therefore be able not only to guarantee a behavior similar to Pt but also to reduce the costs for the electrode fabrication. Several works are available in the literature, discussing the use of catalysts alternative to Pt for the ORR: platinum group metal‐free catalysts, carbon‐based materials, conductive polymers, metal organic frameworks and metal oxides have been proposed. Among the latest, manganese oxides (Mn x O y ) are considered quite interesting candidates, since they combine low cost to electrochemical stability and optimal ORR activity…”

“…Indeed, despite the remarkable potential of the above mentioned catalysts, substantial work is still needed to develop method and techniques that could simplify the preparation of the final electrodes hosting the catalyst during the device operation. Standard approaches are based on the preparation of pastes obtained by mixing the catalytic material turned into a powder (or directly as nanoparticles, depending on the method of synthesis) with binders, and the resulting pastes can then be distributed on the electrode surface . Interest is great toward methods that allow to directly deposit good catalysts on the electrode, according to so called binder‐free methods.…”

An Isolated Zinc–Cobalt Atomic Pair for Highly Active and Durable Oxygen Reduction

“…[5] Follow-up study revealed that, catalysts with bimetallic or multimetallic active sites can further enhance the catalytic activity and selectivity in numerous catalytic conversion reactions. [6] Ar ecently reported Pt-free catalyst with N-coordinated Fe-Co dual sites delivers outstanding activity for ORR in acidic electrolyte. [7] Compared to the single metallic site,t he structure formed by the coordination of dual-metal-atom with nitrogen atoms is more favorable for cracking O 2 bond.…”