| Synthesize ZnFe2O4-ZrO2 as substrate for Pt in Direct methanol fuel cells |
| کد مقاله : 1066-THFC |
| نویسندگان |
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محمد سلیمانی *1، امیرمحمد خسروی2 1دانشگاه تخصصی فناوری های نوین آمل 2دانشگاه صنعتی نوشیروانی بابل |
| چکیده مقاله |
| With the increase of fossil fuel consumption and environment issues, the development of novel energy storage and conversion devices is urgently required. Direct methanol fuel cells (DMFCs) as energy conversion devices possess advantages of low temperature, non-pollution, and high efficient, which have been extensively studied [1]. The performance of DMFCs and SCs always depend on the electrode materials. Pt-based alloys, Pd-based alloys, and nonprecious metal electrocatalysts have attracted significant attention in the field of DMFCs. Precious metal electrocatalysts always possess prefect catalytic ability, while non-precious metals possess inferior catalytic ability. However, precious metal catalysts suffer disadvantages of high price, low content, and poisoning effect. Therefore, more and more researchers focus on the exploitation of novel non-precious metal electrocatalysts with good catalytic ability. Meanwhile, conductive polymers, carbon materials, and transition metal compounds are the common active materials for DMFCs. Among various materials, transition metal compounds can be used as the electrode materials both for DMFCs [2]. Therefore, it is meaningful to design a transition metal compound, which can be used as substrate catalytic activity for methanol oxidation, simultaneously. Mixed transition metal sulfides have attracted much attention because of their superior conductivity, high electrochemical activity, and stability. Ternary zinc ferrite zirconium as one of the most promising candidates possess abundant redox reactions and rich electroactive sites, which can be investigated as electrode materials for electrocatalysts for DMFCs. Herein, we propose a facile method for preparing ZnFe2O4-ZrO2/Pt electrodes, and investigate their electrochemical performance in methanol electrooxidation. As a novel catalyst support, we synthesized ZnFe2O4-ZrO2 for the first time in this study. Using ZnFe2O4-ZrO2/Pt electrocatalyst alloy on modified carbon paste electrodes, Pt electrocatalyst alloy was electrochemically deposited on the surface of ZnFe2O4-ZrO2. This was used as the anode catalyst for MOR [3]. Cyclic voltammetry analyses Fig. 1 illustrates the electrochemical activity of ZnFe2O4-ZrO2/Pt compared with Pt commercial in MOR. These CV traces in Fig. 1 were recorded in a solution of 1.0 M CH3OH+ 0.5 M KOH at a rate of 50 mV s-1. Referring to Fig. 1, the CVs of the two electrocatalysts have two methanol oxidation peaks approximately located at 0.4 and -0.29 V in the forward and reverse scans, respectively. The peak observed in in the positive-going scan originates from the oxidation of methanol molecules adsorbed on the surface of the catalyst leading to the formation of carbonaceous intermediates on the surface of the electrode. In the negative-going potential scan, the peak centered around -0.29 V may be due the residual methanol molecules oxidation adsorbed on the catalyst active sites, and also the oxidation of the remaining carbon-based materials (such as CO) which were not been removed from the catalyst surface in the preceding anodic scan. As shown in Fig. 1, the maximum anodic current density generated by ZnFe2O4-ZrO2/Pt sample reaches 110 mA cm-2 that is almost 42 % higher than that of Pt commercial electrocatalyst (60.27 mA cm-2). The onset of methanol oxidation can be considered as an important parameter to probe the electrochemical performance of the prepared electrocatalysts in MOR at low potential regions. It is seen in Fig. 1 that the onset potential of ZnFe2O4-ZrO2/Pt sample is more negative than that of Pt electrocatalysts (-0.54 V vs. -0.48 V). This observation indicates that the ZnFe2O4-ZrO2/Pt electrocatalyst is capable of promoting MOR when compatred with pure Pt electrocatalysts [4]. Figure 1. CVs of 1.0 M CH3OH in 0.5 M KOH on ZnFe2O4-ZrO2/Pt and Pt samples recorded at a sweep rate of 50 mV s-1. Conclusion Using a simple hydrothermal technique, nanospherical ZnFe2O4-ZrO2 mixed metal oxide nanocomposites with varying ratios were effectively manufactured. Following that, Pt nano-electrocatalyst was electrochemically deposited on the surface of the ZnFe2O4-ZrO2 nanocomposite. To our knowledge, this is the first report on the demonstration of a ZnFe2O4-ZrO2 nanocomposite in a supercapacitor application. The ZnFe2O4-ZrO2/Pt particles displayed a high current density of 110 mA/cm2 with an onset potential of -0.4 V when used as a catalyst for MOR 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). Chen, S., D. Huang, D. Liu, H. Sun, W. Yan, J. Wang, M. Dong, X. Tong, and W. Fan, Hollow and porous NiCo2O4 nanospheres for enhanced methanol oxidation reaction and oxygen reduction reaction by oxygen vacancies engineering. Applied Catalysis B: Environmental, 2021. 291: p. 120065. (3). 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. (4). Shen, L., J. Ying, G. Tian, M. Jia, and X.Y. Yang, Ultralong PtPd alloyed nanowires anchored on graphene for efficient methanol oxidation reaction. Chemistry–An Asian Journal, 2021. 16(9): p. 1130-1137. |
| کلیدواژه ها |
| ZnFe2O4-ZrO2, Nanocomposite, Methanol oxidation reaction, Platinum |
| وضعیت: چکیده برای ارائه پذیرفته شده است |