Co supported on N and S dual-doped reduced graphene oxide as highly active oxygen-reduction catalyst for direct ethanol fuel cells

Influence of the Electrode Deposition Method of Graphene-Based Catalyst Inks for ADEFC on Performance

“…35,36,38 The implementation in the anode catalysts and cathode catalysts as a support material results in improved electron transport and reduced agglomeration of the nanoparticles and thus higher activity. 13,15,22,26,29,30 Beside the research on membranes and catalysts, which is mostly investigated for graphene-based catalysts at the fundamental level by deposition on a glassy carbon substrate using rotating disk experiments, 3,7,8,19 the electrode fabrication or MEA production is another crucial aspect that demands careful consideration. Several options exist for catalyst-powder based production, each of which can impact the stability and reproducibility of the final product.…”

“…Extensive research is currently being conducted on the utilization of graphene compounds in the anodic catalysts, − , cathodic catalysts, − and membranes − for use in alkaline direct ethanol fuel cells (ADEFCs). The ADEFC has emerged as a significant type of fuel cell, garnering increasing importance in recent years.…”

“…Several options exist for catalyst-powder based production, each of which can impact the stability and reproducibility of the final product . The fabrication methods for graphene-based catalysts in solutions, e.g., isopropanol and water, for different fuel cells include spraying, doctor blading, brushing, painting, pasting, and spin coating. ,,,,,,− The restacking of graphene sheets by π–π interactions and strong van der Waals attraction and thus, the aggregation of the catalyst material in solutions during electrode production represents a challenge, as it lowers the overall performance. The reason for the complexity of producing stable suspensions can be attributed to the different hydrophobicity of the various graphene compounds and, therefore, their dissolving behavior. ,− ,− …”

“…However, complete electrochemical C–C bond splitting is not achieved and a product mixture of acetaldehyde (2e – ), acetic acid/acetate (4e – ), and CO 2 /carbonate is formed in the alkaline medium. Therefore, to facilitate the ethanol oxidation reaction and increase the conductivity of the AEMs, alkali (OH – ) is added to the anodic fuel. − To overcome these challenges, the research on the introduction of graphene-based compounds was performed and resulted in lower ethanol permeability, higher conductivity, and thermal stability for the AEMs. ,, The implementation in the anode catalysts and cathode catalysts as a support material results in improved electron transport and reduced agglomeration of the nanoparticles and thus higher activity. ,,,,, …”

Graphite and Cobalt Recycled from Li-Ion Batteries: A Valuable Raw Material for Oxygen Reduction Reaction Electrocatalysts

“…It is mostly suggested that the active sites may be related to the carbon structure, which is modified by nitrogen, while the transition metals only play the role in active-site formation . Co has been suggested as a prominent nonprecious metal catalyst for the ORR because of its exceptional durability in alkaline environments, abundant availability in nature, and cost-effectiveness. − In the synthesis of Co–N–C-based catalysts, diverse Co sources and complexes have been employed. , Furthermore, there has been a novel suggestion to explore the potential of utilizing recycled Co and graphite from spent LIBs. This proposal not only introduces a novel dimension to the central focus of circular economy but also contributes to the development of more sustainable solutions.…”