Carbon-based bifunctional electrocatalysts for oxygen reduction and oxygen evolution reactions: Optimization strategies and mechanistic analysis

Stability challenges of carbon-supported Pt-nanoalloys as fuel cell oxygen reduction reaction electrocatalysts

“…This results in improved MEA performances, especially in the more relevant dry operating conditions. 27,[188][189][190] However, the second main development direction focuses on finding new, better alternatives to CBs. Since the first graphene isolation in 2004 by A. Geim and K. Novoselov, 191 graphene and its derivatives emerged as a potential substitute for CBs as catalyst support.…”

“…In addition to the Pt/C electrocatalyst, there exists 5 main groups of ORR electrocatalysts that are currently in various stages of development, 10 ranging from laboratory validations performed mainly by using half-cell thin-film rotating disc electrode (TF-RDE) evaluation to small scale MEA testing and all the way to fuel cell stack-level testing. Namely, the groups are divided in de-alloyed (ordered or disordered) Pt-alloys, [15][16][17][18][19] core-shell catalysts, 20,21 non-precious group metal (non-PGM) catalysts, [22][23][24][25][26][27][28] shape-controlled Pt-alloy catalysts 29,30 as well as nanoframe Pt-alloy catalysts. 31 What unites all of them is the aim to decrease or even eliminate (namely non-PGM electrocatalysts) the use of Pt and by replacing Pt/C electrocatalysts become the next-generation ORR electrocatalyst system to reach the production phase.…”

Material Choice and Structure Design of Flexible Battery Electrode

“…[ 50 ] By introducing phosphorus, [ 51 ] germanium, [ 52 ] Fe 3 O 4 , [ 53 ] and other activities into the carbon material, the active reaction sites can be increased to improve the electrode capacity or rate performance. [ 9 , 12 , 54 ]…”

Construction of 3D Hierarchical Co3O4@CoFe-LDH Heterostructures with Effective Interfacial Charge Redistribution for Rechargeable Liquid/Solid Zn–Air Batteries

“…As the consumption of conventional fossil fuels increases dramatically, the search for green, efficient, and renewable energies has become a vital issue for the sustainable development of human society. − Meanwhile, with the growing demand for wearable electronics, it is also increasingly essential to explore flexible energy storage devices that are flexible, lightweight, safe, high energy storage, long-life, and mechanically stable. , Metal-air batteries, especially zinc-air batteries (ZABs), are considered ideal energy storage systems for electric vehicles, grid energy storage, wearable portable devices, and other areas by virtue of their high theoretical energy density, reliable safety, low cost, and environmental friendliness. − Previous studies have demonstrated that electrochemical oxygen evolution reaction (OER) plays a crucial role in metal-air batteries and other sustainable energy conversion and storage devices. , Because of the multi-step proton-coupled electron transfer involved, however, the inherently slow kinetics of OER has gravely hindered the development of related technologies. , At present, noble metal-based catalysts, for instance, IrO 2 and RuO 2 , have been demonstrated to effectively promote OER but are still severely plagued by element scarcity, expensive cost, and unsatisfactory stability. , In addition, the polymer binder (Nafion) used for the powder catalysts in ZAB assembly often blocks the active site of nanostructured electrocatalysts and raises interface resistance, which also sets obstacles for high OER catalytic performance. , The preparation of self-supporting catalysts not only facilitates the exposure of active sites and reduces resistance but also enhances the binding force with the substrate to resist severe bubble impact that can occur during the OER process. − Consequently, it is of great value to develop cost-effective and additive-free OER catalysts with high efficiency and superior durability for the practical application and popularization of ZABs.…”