Influence of Solvents on the Electroactivity of PtAl/rGO Catalyst Inks and Anode in Direct Ethanol Fuel Cell

Abstract

This paper presents research on the effects of common solvents such as n-butyl acetate, isopropanol, and ethanol on the properties and electroactivity of catalyst ink based on PtAl/rGO. The inks prepared by mixing PtAl/rGO catalyst, Nafion solution (5 wt%), and solvent were coated on carbon cloth by the spin coating method. The results obtained showed that ethanol was the most suitable solvent for the preparation of catalyst ink with a volume ratio between catalyst slurry and solvent of 1 : 1 (CI-EtOH (1/1) ink). The surface of the CI-EtOH (1/1) coated electrode was smooth, flat, and even and had no cracks due to the increase of Nafion mobility, resulting in significant improvement in the interaction between Pt particles and ionomer. Moreover, the electrochemical activity of the CI-EtOH (1/1) ink in ethanol electrooxidation reaction, in both acidic and alkaline media, has the highest value, with the forward current density, IF, reaching 1793 mA mgPt−1 and 4751 mA mgPt−1, respectively. In the application in direct ethanol fuel cell (DEFC), the CI-EtOH ink-coated anode also exhibited the highest power density in both PEM-DEFC (with a proton exchange membrane) and AEM-DEFC (with an anion exchange membrane) at 19.10 mW cm−2 and 27.07 mW cm−2, respectively.

A Critical Assessment on Functional Attributes and Degradation Mechanism of Membrane Electrode Assembly Components in Direct Methanol Fuel Cells

“…Pt/Ru supported on TiO 2 embedded carbon nanofibers (Pt-Ru/TECNF), was reported as a highly active catalyst for methanol oxidation, which demonstrated reduced agglomeration compared to the conventional Pt catalysts supported on carbon [178,179]. A study reported that using ethanol solvent as catalyst ink for anode catalyst increased the interaction between Pt particles and ionomer, resulting in reduced agglomeration [180]. A similar study reported that using N-methyl pyrrolidone and dimethyl sulfoxide as catalyst ink enables the reduction of catalysts agglomeration [181].…”

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

“…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. ,− ,− …”