The use of avocado seed self‐assembly monolayer films for the catalysis of methanol electrooxidation reaction

Abstract

Catalysts are important equipment that limits the performance of direct methanol fuel cells (DMFC). With the use of appropriate electrocatalysts, the efficiency of DMFC can be increased. Although the platinum-based catalysts have high efficiency for this process high cost and its limited sources on the earth are the main drawbacks. On the other hand, platinum affectivity may be alternative material due to its high resistance against CO-poisoning on the electrode/solution interface. They have also a low cost. In this study, the extracts of avocado seed (AS) are prepared in ethanol solvent and their self-assembly monolayer (SAM) films were prepared on the copper specimens (Cu/AS-SAM). The AS-SAM film modified catalyst was used as anode material for electrooxidation of methanol in an alkaline solution. To increase catalytic efficiency, the surface of Cu/AS-SAM was modified by electrodeposition of Ni. The surfaces of the bare copper, the AS-SAM film, and the Ni-modified were described by SEM, AFM, and EDX-mapping measurements. Their electrocatalytic activity and stability were evaluated with 1.0 M methanol containing alkaline solution by cyclic voltammetry (CV), Tafel curves and chronoamperometry (CA) tests. The results showed that a durable and homogeneous AS-SAM film forms on the copper surface from the extracts of AS in ethanol solvent. The AS-SAM film is electroactive for the methanol electrooxidation reaction. Moreover, modification of the film by depositing with Ni enhances its activity. The AS, agriculture waste can be utilized for fabricating anode materials for methanol electrooxidation reactions.