全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...
电化学  2011 

CO2在Cu表面还原成碳氢化合物的DFT计算研究

, PP. 155-160

Keywords: 密度泛函理论计算,CO2还原,反应路径

Full-Text   Cite this paper   Add to My Lib

Abstract:

应用密度泛函理论(DFT)反应能计算及最小能量路径分析研究了CO2在气相和电化学环境中于Cu(111)单晶表面的还原过程。气相中,CO2还原为碳氢化合物的反应路径可能为:CO2(g)+H*→COOH*→(CO+OH)*→CHO*;CHO+H*→CH2O*→(CH2+O)*;CH2*+2H*→CH4或2CH2*→C2H4。整个反应由CO2(g)+H*→COOH*→(CO+OH)*,(CO+H)*→CHO*和CH2O*→(CH2+O)*等几个步骤联合控制。在-0.50V(vsRHE)以正的电势下,CO2在Cu(111)表面电化学还原主要形成HCOO-和CO吸附物;随着电势逐渐负移,CO2加氢解离形成CO的反应越来越容易,CO成为主要产物;随电势进一步变负,形成碳氢化合物的趋势逐渐变强。与CO2的气相化学还原不同的是,电化学环境下CO质子化形成的CHO中间体倾向于解离形成CH,而在气相中CHO中间体则倾向于进一步质子化形成CH2O中间体。

References

[1]  Hori Y. In Environmental Aspects of Electrochemistry and Photoelectrochemistry; Tomkiewicz M, Haynes R, Yoneyama H, Hori Y, Eds.; The Electrochemical Society: Pennington, NJ, 1993, p1.
[2]  Hori Y, Wakebe H, Tsukamoto T, Koga O. Adsorption of CO accompanied with simultaneous charge transfer on copper single crystal electrodes related with electrochemical reduction of CO2 to hydrocarbons. Surf. Sci., 1995, 335: 258-263.
[3]  Hori Y, Takahashi I, Koga O, Hoshi N. Selective Formation of C2 Compounds from Electrochemical Reduction of CO2 at a Series of Copper Single Crystal Electrodes. J. Phys. Chem. B, 2002, 106: 15-17.
[4]  Perdew JP, Burke K, Ernzerhof M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996, 77: 3865-3868.
[5]  Vanderbilt D. Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Phys. Rev. B. 1990, 41: 7892-7895.
[6]  Methfessel M, Paxton AT. High-precision sampling for Brillouin-zone integration in metals. Phys. Rev. B. 1989, 40: 3616-3621.
[7]  Baroni S, Dal Corso A, de Gironcoli S, Giannozzi P. PWSCF and PHONON: Plane-Wave Pseudo-Potential Codes. http://www.pwscf.org, 2001.
[8]  Henkelman G, Jonsson H. Improved tangent estimate in the nudged elastic band method for finding minimum energy paths and saddle points. J. Chem. Phys. 2000, 113: 9978-9985.
[9]  Henkelman G, Uberuaga BP, Jonsson H. A climbing image nudged elastic band method for finding saddle points and minimum energy paths. J. Chem. Phys. 2000, 113: 9901-9904.
[10]  Noda H, Ikeda S, Oda Y, Ito K. Potential Dependencies of the Products on Electrochemical Reduction of Carbon Dioxide at a Copper Electrode. Chem. Lett. 1989, 18: 289-292.

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133