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DOI	10.1073/pnas.2023233118
	Fundamental insight into electrochemical oxidation of methane towards methanol on transition metal oxides
	Prajapati A.; Collins B.A.; Goodpaster J.D.; Singh M.R.
发表日期	2021
ISSN	00278424
卷号	118 期号:8
英文摘要	Electrochemical oxidation of CH4 is known to be inefficient in aqueous electrolytes. The lower activity of methane oxidation reaction (MOR) is primarily attributed to the dominant oxygen evolution reaction (OER) and the higher barrier for CH4 activation on transition metal oxides (TMOs). However, a satisfactory explanation for the origins of such lower activity of MOR on TMOs, along with the enabling strategies to partially oxidize CH4 to CH3OH, have not been developed yet. We report here the activation of CH4 is governed by a previously unrecognized consequence of electrostatic (or Madelung) potential of metal atom in TMOs. The measured binding energies of CH4 on 12 different TMOs scale linearly with the Madelung potentials of the metal in the TMOs. The MOR active TMOs are the ones with higher CH4 binding energy and lower Madelung potential. Out of 12 TMOs studied here, only TiO2, IrO2, PbO2, and PtO2 are active for MOR, where the stable active site is the O on top of the metal in TMOs. The reaction pathway for MOR proceeds primarily through CHx intermediates at lower potentials and through CH3OH intermediates at higher potentials. The key MOR intermediate CH3OH is identified on TiO2 under operando conditions at higher potential using transient open-circuit potential measurement. To minimize the overoxidation of CH3OH, a bimetallic Cu2O3 on TiO2 catalysts is developed, in which Cu reduces the barrier for the reaction of CH3 and OH and facilitates the desorption of *CH3OH. The highest faradaic efficiency of 6% is obtained using Cu-Ti bimetallic TMO. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Binding energy measurement; Density functional theory; Electrochemical oxidation of methane; Methanol synthesis; Transient open-circuit potential
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180521
作者单位	Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States; Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN 55455, United States
推荐引用方式 GB/T 7714	Prajapati A.,Collins B.A.,Goodpaster J.D.,et al. Fundamental insight into electrochemical oxidation of methane towards methanol on transition metal oxides[J],2021,118(8).
APA	Prajapati A.,Collins B.A.,Goodpaster J.D.,&Singh M.R..(2021).Fundamental insight into electrochemical oxidation of methane towards methanol on transition metal oxides.Proceedings of the National Academy of Sciences of the United States of America,118(8).
MLA	Prajapati A.,et al."Fundamental insight into electrochemical oxidation of methane towards methanol on transition metal oxides".Proceedings of the National Academy of Sciences of the United States of America 118.8(2021).