| Preparation of graphene oxide/molybdenum disulfide nanocomposite as a platinum-nickel electrocatalyst substrate |
| کد مقاله : 1067-THFC |
| نویسندگان |
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محمد سلیمانی * دانشگاه تخصصی فناوری های نوین آمل |
| چکیده مقاله |
| Abstract In this study, graphene oxide/molybdenum disulfide (GO/MOS2) nanocomposite was prepared using in-situ polymerization method. Next the platinum-nickel (Pt-Ni) was electrochemically decorated on GO/MOS2 nanocomposite surface. Cyclic voltammetry (CV) was employed to evaluate the oxidation of ethanol. Results showed that Pt-Ni/GO/MOS2 exhibits improved electrocatalytic activity ethanol oxidation. Enhanced active surface area of the Pt-Ni/GO/MOS2 electrode (225 mA/cm2) contributes to increase in current density values in the ethanol oxidation as compared to Pt-Pd electrocatalyst. Keywords: Graphene oxide, Molybdenum disulfide , Methanol oxidation reaction, Platinum Introduction The growing energy demand is one of the critical issues faced by the humanity in this era and massive combustion of fossil fuels has led to severe energy crisis and environmental pollution [1]. Fuel cell is one of the thrust areas where research is active to solve the issue of energy crisis. Amongst the different types of fuel cells, direct ethanol fuel cell (DEFC) received considerable attention due to its superior specific energy, operational safety and low cost [2]. In DEFC, the most commonly used catalyst for ethanol oxidation is platinum (Pt). Nonetheless, the large scale applications have seriously hindered because Pt is limited and expensive [2]. Therewith, previous researches have revealed that the alloys of Pt which has a second metal (like Bi, Sn, Ru, Ni, and Pd) can speed up the oxidation of ethanol, decrease the Pt loading and also improve the CO tolerance of Pt [2]. In the running research, Pt-Ni alloy was electrochemically deposited on the surface of GO/MOS2 in order to improve the performance of Pt-Ni modified carbon paste electrode (CPE) as anode catalyst for oxidation of ethanol. Produced electrocatalyst was characterized cyclic voltammograms to appraise the electro-activity of Pt-Ni/GO/MOS2 electrode. The present study shows that the Pt-Ni/GO/MOS2 nanoparticulate can be a promising catalyst for portable applications in DEFC in alkaline solution. CV experiments Fig. 1 shows the stabilized cyclic voltammetry curves (CV's) recorded for methanol electro oxidation at the prepared electrode. Curves display a single peak during the positive-going sweep that is characteristic of the electro oxidation of MeOHads molecules on Pt based catalysts. After passing through the maximum, the current density decreases progressively due to platinum oxide formation and then starts to increase again due to incomplete alcohol oxidation. In the backward scan the corresponding oxidation peak is shifted to a less positive potential and the oxidation process proceeds with high reactivation currents. This anodic peak is attributed to the further removal/oxidation of adsorbed by-products and CO, and/or oxidation of alcohol molecules on the freed catalytic sites. The onset potential for methanol oxidation reaction on Pt-Ni/GO/MOS2 catalysts occurred at -0.5 V which indicates that Pt-Ni/GO/MOS2 nanocomposites improve kinetics of methanol electro oxidation. The specific peak current densities for methanol oxidation reaction were 225 mA/cm2 for Pt-Ni/GO/MOS2 although, specific activity is directly related to the number of active sites on the catalyst surface and, the cathodic peak in the backward scan was detected that was related to the oxidation of remaining methanol and the removal of residual carbonaceous oxygen containing intermediates formed during the forward scan. Fig. 1. Cyclic voltammograms of the Pt-Ni/GO/MOS2, Pt/GO/MOS2, Pt-Ni, Pt-Ni/GO and Pt-Ni/MOS2 in 0.5 M KOH and 1.0 M methanol electrolyte at 50 mV/s scan rate. Conclusion The present study was designed to determine the influence of GO/MOS2 on the electro catalytic activity of Pt-Ni alloy nanoparticles synthesized for methanol oxidation. Cyclic voltammetry was employed to evaluate the catalytic performance of the supported alloy nanoparticles for methanol oxidation reaction. The results indicated that the GO/MOS2 supported Pt-CoNi catalyst exhibits the best performance for methanol oxidation. References (1). Tian, H., et al., Recent advances in two-dimensional Pt based electrocatalysts for methanol oxidation reaction. International Journal of Hydrogen Energy, 2021. 46(61): p. 31202-31215. (2). Yuda, A., A. Ashok, and A. Kumar, A comprehensive and critical review on recent progress in anode catalyst for methanol oxidation reaction. Catalysis Reviews, 2022. 64(1): p. 126-228. |
| کلیدواژه ها |
| Graphene oxide, Molybdenum disulfide , Methanol oxidation reaction, Platinum |
| وضعیت: چکیده برای ارائه پذیرفته شده است |