Journal of the American Chemical Society p. 16412 - 16419 (2017)
Update date:2022-08-10
Topics:
Pérez-Gallent, Elena
Marcandalli, Giulia
Figueiredo, Marta Costa
Calle-Vallejo, Federico
Koper, Marc T. M.
The complexity of the electrocatalytic reduction of CO to CH4 and C2H4 on copper electrodes prevents a straightforward elucidation of the reaction mechanism and the design of new and better catalysts. Although structural and electrolyte effects have been separately studied, there are no reports on structure-sensitive cation effects on the catalyst's selectivity over a wide potential range. Therefore, we investigated CO reduction on Cu(100), Cu(111), and Cu(polycrystalline) electrodes in 0.1 M alkaline hydroxide electrolytes (LiOH, NaOH, KOH, RbOH, CsOH) between 0 and -1.5 V vs RHE. We used online electrochemical mass spectrometry and high-performance liquid chromatography to determine the product distribution as a function of electrode structure, cation size, and applied potential. First, cation effects are potential dependent, as larger cations increase the selectivity of all electrodes toward ethylene at E > -0.45 V vs RHE, but methane is favored at more negative potentials. Second, cation effects are structure-sensitive, as the onset potential for C2H4 formation depends on the electrode structure and cation size, whereas that for CH4 does not. Fourier Transform infrared spectroscopy (FTIR) and density functional theory help to understand how cations favor ethylene over methane at low overpotentials on Cu(100). The rate-determining step to methane and ethylene formation is CO hydrogenation, which is considerably easier in the presence of alkaline cations for a CO dimer compared to a CO monomer. For Li+ and Na+, the stabilization is such that hydrogenated dimers are observable with FTIR at low overpotentials. Thus, potential-dependent, structure-sensitive cation effects help steer the selectivity toward specific products.
View MoreTaizhou YOJOY Chemical Co., Ltd.
Contact:13857143241
Address:Yangfu Industrial Park, Xianju, Zhejiang, P. R. China
Yuan Shi(SuQian)Biotechnology Co.,Ltd
website:http://www.yuanshibio.com
Contact:+86-527-84226672
Address:jiangsu suqian
Hangzhou Deli Chemical Co.,Ltd.
website:http://www.dlchemical.com
Contact:86 571 28006267
Address:Tangxi Industrial Area, Yuhang District, Hangzhou
Shandong LuZhou Amino Acid Co., Ltd
Contact:86-539-2218025
Address:yishui economic and technical development zone zhenxing south road
Guangzhou Chemical Reagent Factory
Contact:+86-20-8435 9820 or 8435 7345
Address:Southern Guangzhou, Guangdong, China
Doi:10.1021/jp036432o
(2004)Doi:10.1016/S0040-4039(00)94955-4
(1985)Doi:10.1039/d1dt01421h
(2021)Doi:10.1021/ja01617a002
(1955)Doi:10.1002/zaac.201700376
(2018)Doi:10.1134/S096554411912003X
(2019)