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intensity increases with increasing electrolysis time. The
appearance of the CH3 peak at 1420 cmÀ2 indicates formation
of methanol.
Acknowledgements
We thank the National Natural Science Foundation of China
(21133009, 21403253, 21533011, 21321063).
The high electrocatalytic selectivity of the Mo-Bi BMC/
CP electrode can be attributed to the synergistic effect
between Mo and Bi for producing methanol. Supporting
Information, Figure S10B shows that the Bi-based electrode
has high efficiency for conversion of CO2 to CO, which is
consistent with the conclusion reported by other authors.[7] In
other words, Bi sites can efficiently drive CO generation in
the presence of an IL. On the other hand, the Mo-based
electrode is favorable for producing H2, as can be seen from
Supporting Information, Figure S10C. In addition, Mo sites
can bind with CO,[23] which favors the further reduction of CO
to methanol. Therefore, it can be deduced that Mo and Bi in
the Mo-Bi BMC/CP electrode work synergistically for
producing methanol because CO and H2 can be produced
on the electrode, the CO is bound and can be further
hydrogenated to methanol. In addition, the better perfor-
mance of Mo-Bi BMC than Mo-Ag and Mo-Cu BMC can be
attributed to the ability of Bi sites for stabilizing CO2CÀ
intermediates in the presence of IL.[7]
On the basis of the experimental results and the related
knowledge in the literature, we propose a speculative mech-
anism for the electrochemical reduction of CO2 to methanol
over the Mo-Bi BMC/CP electrode, which is shown schemati-
cally in Supporting Information, Figure S13. In the first step,
a complex [Bmim-CO2]+ can form quickly through the
hydrogen bonding interaction between CO2 and [Bmim]+
cation.[38] This process may reduce the reaction barrier for
electron transfer to CO2, which plays a crucial role for
reducing the overpotential of the reaction.[39] The complex
can be adsorbed on the electrode surface and the CO2
molecule is reduced to CO2CÀ,[39,40] which can be inferred
from the Tafel plot. The free-energy pathway becomes
thermodynamically downhill to transfer the second electron
to form adsorbed CO (COads). Then, the COads can be
converted into CHOads after accepting an electron and proton.
The protonation of CHOads leads to the formation of CH3Oads
by capturing another two electrons. Finally, the downstream
step is the transformation of CH3Oads to methanol after
accepting the last electron and proton.
Keywords: bimetallic chalcogenides · carbon dioxide ·
electrocatalysis · nanosheets · ionic liquids
How to cite: Angew. Chem. Int. Ed. 2016, 55, 6771–6775
Angew. Chem. 2016, 128, 6883–6887
[1] M. He, Y. Sun, B. Han, Angew. Chem. Int. Ed. 2013, 52, 9620 –
9633; Angew. Chem. 2013, 125, 9798 – 9812.
[2] I. Dimitriou, P. Garcia-Gutierrez, R. H. Elder, R. M. Cuellar-
Franca, A. Azapagic, R. W. K. Allen, Energy Environ. Sci. 2015,
8, 1775 – 1789.
[3] M. Aresta, A. Dibenedetto, A. Angelini, Chem. Rev. 2014, 114,
1709 – 1742.
[4] M. Alvarez-Guerra, J. Albo, E. Alvarez-Guerra, A. Irabien,
Energy Environ. Sci. 2015, 8, 2574 – 2599.
[5] J. Qiao, Y. Liu, F. Hong, J. Zhang, Chem. Soc. Rev. 2014, 43, 631 –
675.
[6] B. Kumar, M. Asadi, D. Pisasale, S. Sinha-Ray, B. A. Rosen, R.
Haasch, J. Abiade, A. L. Yarin, A. Salehi-Khojin, Nat. Commun.
2013, 4, 3819.
[7] J. L. DiMeglio, J. Rosenthal, J. Am. Chem. Soc. 2013, 135, 8798 –
8801.
[8] J. Shen, R. Kortlever, R. Kas, Y. Y. Birdja, O. Diaz-Morales, Y.
Kwon, I. Ledezma-Yanez, K. J. P. Schouten, G. Mul, M. T. M.
Koper, Nat. Commun. 2015, 6, 9177.
[9] D. Kim, J. Resasco, Y. Yu, A. M. Asiri, P. Yang, Nat. Commun.
2014, 5, 5948.
[10] S. Gao, Y. Lin, X. Jiao, Y. Sun, Q. Luo, W. Zhang, D. Li, J. Yang,
Y. Xie, Nature 2016, 529, 68 – 71.
[11] N. Hollingsworth, S. F. R. Taylor, M. T. Galante, J. Jacquemin, C.
Longo, K. B. Holt, N. H. de Leeuw, C. Hardacre, Angew. Chem.
Int. Ed. 2015, 54, 14164 – 14168; Angew. Chem. 2015, 127, 14370 –
14374.
[12] S. Zhang, P. Kang, S. Ubnoske, M. K. Brennaman, N. Song, R. L.
House, J. T. Glass, T. J. Meyer, J. Am. Chem. Soc. 2014, 136,
7845 – 7848.
[13] R. Angamuthu, P. Byers, M. Lutz, A. L. Spek, E. Bouwman,
Science 2010, 327, 313 – 315.
[14] K. P. Kuhl, T. Hatsukade, E. R. Cave, D. N. Abram, J. Kibsgaard,
T. F. Jaramillo, J. Am. Chem. Soc. 2014, 136, 14107 – 14113.
[15] X. Kang, Q. Zhu, X. Sun, J. Hu, J. Zhang, Z. Liu, B. Han, Chem.
Sci. 2016, 7, 266 – 273.
[16] K. Manthiram, B. J. Beberwyck, A. P. Alivisatos, J. Am. Chem.
Soc. 2014, 136, 13319 – 13325.
[17] F. S. Roberts, K. P. Kuhl, A. Nilsson, Angew. Chem. Int. Ed. 2015,
54, 5179 – 5182; Angew. Chem. 2015, 127, 5268 – 5271.
[18] Y. Liu, S. Chen, X. Quan, H. Yu, J. Am. Chem. Soc. 2015, 137,
11631 – 11636.
In summary, Mo-Bi BMC/CP with a Mo:Bi molar ratio of
1:1 is a very efficient and stable electrode for the electro-
chemical reduction of CO2 to methanol. When 0.5m
[Bmim]BF4 in MeCN is used as the electrolyte, the Faradaic
efficiency for CO2 electrochemical reduction to methanol can
be as high as 71.2% with a current density of 12.1 mAcmÀ2,
which is much higher than the values reported up to now. The
high electrocatalytic selectivity of the Mo-Bi BMC/CP
electrode can be attributed to the synergistic effect between
Mo and Bi for producing methanol. The Bi enhances the
transformation of CO2 to CO, and the Mo favors the
generation of H2 and can bind CO. Thus, the CO is bound
and can be further hydrogenated to obtain methanol. It may
[19] J. Graciani, K. Mudiyanselage, F. Xu, A. E. Baber, J. Evans, S. D.
Senanayake, D. J. Stacchiola, P. Liu, J. Hrbek, J. Fernandez Sanz,
J. A. Rodriguez, Science 2014, 345, 546 – 550.
[20] F. Studt, I. Sharafutdinov, F. Abild-Pedersen, C. F. Elkjær, J. S.
Hummelshøj, S. Dahl, I. Chorkendorff, J. K. Nørskov, Nat.
Chem. 2014, 6, 320 – 324.
[21] J. Qu, X. Zhang, Y. Wang, C. Xie, Electrochim. Acta 2005, 50,
3576 – 3580.
[22] Y. Hori, A. Murata, R. Takahashi, S. Suzuki, J. Chem. Soc. Chem.
Commun. 1988, 17 – 19.
proceed with the pathway of CO2!CO2·À!COads
!
CHOads!CH3Oads!methanol. This work provides a new
and efficient route to produce methanol from CO2.
[23] D. P. Summers, S. Leach, K. W. Frese, Jr., J. Electroanal. Chem.
1986, 205, 219 – 232.
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Angew. Chem. Int. Ed. 2016, 55, 6771 –6775