气候变化领域集成服务门户(CCPortal): Methanol tolerance of atomically dispersed single metal site catalysts: Mechanistic understanding and high-performance direct methanol fuel cells

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DOI	10.1039/d0ee01968b
	Methanol tolerance of atomically dispersed single metal site catalysts: Mechanistic understanding and high-performance direct methanol fuel cells
	Shi Q.; He Y.; Bai X.; Wang M.; Cullen D.A.; Lucero M.; Zhao X.; More K.L.; Zhou H.; Feng Z.; Liu Y.; Wu G.
发表日期	2020
ISSN	17545692
起始页码	3544
结束页码	3555
卷号	13 期号:10
英文摘要	Proton-exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) are promising power sources from portable electronic devices to vehicles. The high-cost issue of these low-temperature fuel cells can be primarily addressed by using platinum-group metal (PGM)-free oxygen reduction reaction (ORR) catalysts, in particular atomically dispersed metal-nitrogen-carbon (M-N-C, M = Fe, Co, Mn). Furthermore, a significant advantage of M-N-C catalysts is their superior methanol tolerance over Pt, which can mitigate the methanol cross-over effect and offer great potential of using a higher concentration of methanol in DMFCs. Here, we investigated the ORR catalytic properties of M-N-C catalysts in methanol-containing acidic electrolytes via experiments and density functional theory (DFT) calculations. FeN4 sites demonstrated the highest methanol tolerance ability when compared to metal-free pyridinic N, CoN4, and MnN4 active sites. The methanol adsorption on MN4 sites is even strengthened when electrode potentials are applied during the ORR. The negative influence of methanol adsorption becomes significant for methanol concentrations higher than 2.0 M. However, the methanol adsorption does not affect the 4e- ORR pathway or chemically destroy the FeN4 sites. The understanding of the methanol-induced ORR activity loss guides the design of promising M-N-C cathode catalyst in DMFCs. Accordingly, we developed a dual-metal site Fe/Co-N-C catalyst through a combined chemical-doping and adsorption strategy. Instead of generating a possible synergistic effect, the introduced Co atoms in the first doping step act as "scissors"for Zn removal in metal-organic frameworks (MOFs), which is crucial for modifying the porosity of the catalyst and providing more defects for stabilizing the active FeN4 sites generated in the second adsorption step. The Fe/Co-N-C catalyst significantly improved the ORR catalytic activity and delivered remarkably enhanced peak power densities (i.e., 502 and 135 mW cm-2) under H2-air and methanol-air conditions, respectively, representing the best performance for both types of fuel cells. Notably, the fundamental understanding of methanol tolerance, along with the encouraging DMFC performance, will open an avenue for the potential application of atomically dispersed M-N-C catalysts in other direct alcohol or ammonia fuel cells. © The Royal Society of Chemistry.
英文关键词	Adsorption; Ammonia; Catalyst activity; Density functional theory; Design for testability; Electrodes; Electrolytic reduction; Gas fuel purification; Iron compounds; Manganese compounds; Metal-Organic Frameworks; Metals; Methanol; Methanol fuels; Mobile power plants; Organometallics; Oxygen reduction reaction; Proton exchange membrane fuel cells (PEMFC); Temperature; Direct methanol fuel cells (DMFCs); Low temperature fuel cells; Metalorganic frameworks (MOFs); Methanol concentration; Methanol tolerance abilities; Platinum group metals; Portable electronic devices; Proton exchange membrane fuel cell (PEMFCs); Direct methanol fuel cells (DMFC); Hyporhamphus hildebrandi
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/189509
作者单位	Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, United States; Texas Materials Institute and Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712, United States; School of Chemical Biological and Environmental Engineering Oregon State University, Corvallis, OR 97331, United States; Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States; X-Ray Science Division, Argonne National Laboratory, Lemont, IL 60439, United States
推荐引用方式 GB/T 7714	Shi Q.,He Y.,Bai X.,et al. Methanol tolerance of atomically dispersed single metal site catalysts: Mechanistic understanding and high-performance direct methanol fuel cells[J],2020,13(10).
APA	Shi Q..,He Y..,Bai X..,Wang M..,Cullen D.A..,...&Wu G..(2020).Methanol tolerance of atomically dispersed single metal site catalysts: Mechanistic understanding and high-performance direct methanol fuel cells.Energy & Environmental Science,13(10).
MLA	Shi Q.,et al."Methanol tolerance of atomically dispersed single metal site catalysts: Mechanistic understanding and high-performance direct methanol fuel cells".Energy & Environmental Science 13.10(2020).