Metal-Free Nitrogen-Doped Mesoporous Carbon for Electroreduction of CO2 to Ethanol

Article abstract of DOI:10.1002/anie.201706777

CO₂ electroreduction is a promising technique for satisfying both renewable energy storage and a negative carbon cycle. However, it remains a challenge to convert CO₂ into C2 products with high efficiency and selectivity. Herein, we report a nitrogen-doped ordered cylindrical mesoporous carbon as a robust metal-free catalyst for CO₂ electroreduction, enabling the efficient production of ethanol with nearly 100 % selectivity and high faradaic efficiency of 77 % at ?0.56 V versus the reversible hydrogen electrode. Experiments and density functional theory calculations demonstrate that the synergetic effect of the nitrogen heteroatoms and the cylindrical channel configurations facilitate the dimerization of key CO* intermediates and the subsequent proton–electron transfers, resulting in superior electrocatalytic performance for synthesizing ethanol from CO₂.

Full text of DOI:10.1002/anie.201706777

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Accepted Article
Title: Metal-Free Nitrogen-Doped Mesoporous Carbon for
Electroreduction of CO2 to Ethanol
Authors: Yanfang Song, Wei Chen, Chengcheng Zhao, Shenggang Li,
Wei Wei, and Yuhan Sun
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Angewandte Chemie International Edition
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COMMUNICATION
Metal-Free Nitrogen-Doped Mesoporous Carbon for
Electroreduction of CO to Ethanol
2
Yanfang Song,Wei Chen,* Chengcheng Zhao, Shenggang Li, Wei Wei, and Yuhan Sun*
Abstract: CO
satisfying both renewable energy storage and negative carbon cycle.
However, it remains a challenge to convert CO to C2 products with
2
electroreduction is
a
promising technique for
formic acid could be produced from these N-doped carbon
nanostructures, which were incapable of stabilizing the active C1
intermediates for their coupling to generate multi-carbon
products, especially C2 products.
2
high efficiency and selectivity. Herein, we report a nitrogen-doped
ordered cylindrical mesoporous carbon as a robust metal-free
To date, reports on developing efficient metal-free
catalyst for CO
ethanol with nearly 100% selectivity and high faradaic efficiency of
7% at −0.56 V versus the reversible hydrogen electrode. Our
2
electroreduction, enabling the efficient production of
functionalized carbon materials for CO
products were extremely rare. Ajayan et al.
2
electroreduction to C2
[
16]
have recently
7
developed N-doped graphene quantum dot (NGQD) catalysts by
reducing the sizes of the carbon nanostructures to nano-scale,
which would favor the production of multi-carbon compounds
including ethylene, ethanol, and n-propanol. Unfortunately,
NGQDs exhibited very broad product distributions and low
faradaic efficiencies (FEs), with maximum FEs were 31% and
16% for the major products ethylene and ethanol, respectively,
at -0.75 V (vs. the reversible hydrogen electrode, RHE).
experiments and density functional theory calculations demonstrate
that the synergetic effect of the nitrogen heteroatoms and the
cylindrical channel configurations facilitates the dimerization of key
CO* intermediates and the subsequent proton-electron transfers,
resulting in superior electrocatalytic performance for synthesizing
2
ethanol from CO .
Efficiently and selectively producing C2 compounds from CO
electroreduction still remains a challenge.
Herein, we report an exploration of a class of mesoporous N-
doped carbon tailored with highly uniform cylindrical channel
2
2
Accumulation of greenhouse gas CO in the atmosphere from
the industrial-sale fossil energy consumption causes the global
warming and threatens the human sustainable development. As
2
a remedy, CO can be electroreduced to value-added chemicals
structures to dramatically boost C-C bond formation in CO
2
or fuels driven by low-grade renewable electricity, enabling both
renewable energy storage and negative carbon cycle.[1-3] As the
electroreduction. Ordered mesoporous carbons possess several
great benefits for electrocatalysis, such as large specific surface
catalysts for CO
2
electroreduction, metals[4-7] and metallic
area, tunable pore structure, uniform channel, chemical stability
complexes[8-10] have been extensively investigated. However,
these metal-containing catalysts share obvious disadvantages
such as high cost, limited availability, potential toxicity, and poor
durability due to the leaching of the active metal components.
Recently, metal-free N-doped carbon materials have been
[17,18]
and high electric conductivity.
By doping mesoporous
carbon with nitrogen, the resulting catalyst, specifically metal-
free cylindrical mesoporous N-doped carbon (denoted as c-NC),
can convert CO into ethanol with FE as high as 77% at the low
2
potential of −0.56 V (vs. RHE), which was accomplished at
ambient atmosphere in aqueous solution. The active pyridinic
and pyrrolic N sites were uniformly distributed on the inner
surface of the cylindrical channel, which efficiently supply the
electrons for the dimerization of the CO* intermediates to
reported for CO
2
electroreduction applications, reaching
comparable catalytic activities to metal-based catalysts while
possessing advantages such as better durability.[11-15]
Incorporating nitrogen heteroatoms into the carbon matrixes can
increase charge density and transform the inert carbon
structures to be highly active. For instance, N-doped carbon
nanofiber (NCNF),[12] N-doped carbon nanotube (NCNT),[13]
polyethylenimine functionalized NCNT[14] and graphitic carbon
2
produce ethanol. As the competitive CO reduction into CO or
other products was completely suppressed, an almost 100%
selectivity to ethanol was achieved.
The catalyst c-NC was synthesized by a soft-template method
via the self-assembly of resol (the carbon precursor), F127 (the
soft template) and dicyandiamide (the nitrogen precursor) (see
Supporting Information (SI) for details). The synthesized c-NC
possesses the distinctive cylindrical channels embedded in the
bulk of carbon. To highlight the superiority of such cylindrical
mesoporous structure, a counterpart of c-NC, i.e., the inverse
mesoporous N-doped carbon (denoted as i-NC) that preserves
similar pore parameters, was also prepared for comparison (see
SI for details). The nitrogen contents of c-NC and i-NC were
strictly controlled to be the same.
nitride/CNT[15] have been used as effective catalysts for CO
electroreduction. However, only C1 compounds such as CO or
2
[*]
Dr. Y. Song, Prof. W. Chen, C. Zhao, Prof. S. Li, Prof. W. Wei, Prof.
Y. Sun
CAS Key Laboratory of Low-Carbon Conversion Science and
Engineering, Shanghai Advanced Research Institute
Chinese Academy of Sciences
100 Haike Road, Shanghai 201203 (People Republic of China)
E-mail: chenw@sari.ac.cn
Prof. S. Li, Prof. W. Wei, Prof. Y. Sun
School of Physical Science and Technology
ShanghaiTech University
As shown in the scheme (Figure 1A), the catalysts c-NC and i-
NC show different electrocatalytic performances, indicating that
the structure configurations of N-doped carbon materials play a
393 Middle Huaxia Road, Shanghai 201210 (People Republic of
China)
E-mail: sunyh@sari.ac.cn
crucial role during CO
2
reduction. Transmission electron
microscopy (TEM) observations revealed that c-NC (Figure 1B
a1 and a2) exhibited large domains of highly ordered cylindrical
Supporting information for this article is given via a link at the end of
the document
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COMMUNICATION
and strip-like mesopores viewed along [110] and perpendicular
removal of the silica template. These analyses clearly showed
the ordered mesostructures of both c-NC and i-NC, consistent
with the TEM and SAXS characterizations.
[
100] to the two-dimensional (2D) hexagonal mesostructure,
respectively. As for i-NC (Figure 1B b1 and b2), the
mesostructure was an inverse replica of the mesoporous silica
template (Figure S1 e and f).
In the Raman spectra, both c-NC and i-NC presented two
-1
Raman bands centered around 1345 and 1590 cm , which
correspond to the characteristic G and D modes of graphitic
carbons, respectively (Figure 1D). The D peak is ascribed to the
disorder-induced defects, and the G peak corresponds to the
symmetry-allowed graphite band. The intensity ratio between the
D and G peaks (I
D G
/I ) for c-NC was 2.5, smaller than that of i-NC
(
2.7), indicating more defects in i-NC. This may arise from local
framework collapse caused by HF etching during the preparation
of i-NC (see SI for details).
The nitrogen concentration and its atomic configurations were
investigated by X-ray photoelectron spectroscopy (XPS). The
total N content in c-NC was 7.0 at% based on the N/(C+N)
atomic ratio, slightly lower than that in i-NC of 7.2 at%. The high-
resolution N1s XPS spectra of both c-NC and i-NC were
deconvoluted into three sub-peaks, corresponding to pyridinic N
(
398.3 eV), pyrrolic N (400.4 eV), and graphitic N (401.1 eV),
respectively, which reside in the carbon frameworks (Figure 1E).
The individual atomic concentrations of pyridinic, pyrrolic and
graphitic N atoms were 2.6, 2.8 and 1.6 at% for c-NC,
respectively, and 1.9, 3.9 and 1.4 at% for i-NC, respectively. The
N heteroatoms, more electronegative than C atoms, induce the
adjacent carbon atoms to be positively charged, which are
electroreduction.[ To
12]
considered as the active sites for CO
verify the CO
2
2
catalytic function due to the N heteroatoms, we
prepared the analogous cylindrical mesoporous carbon (denoted
as c-MC) and the inverse mesoporous carbon (denoted as i-MC)
without N doping as the reference catalysts. The structure
parameters of c-MC and i-MC were precisely controlled to be
identical to c-NC and i-NC, respectively (see SI for the detailed
preparation and characterization). The control experiments
showed that hydrogen, evolved from hydrogen evolution
reaction (HER), was the only product over c-MC and i-MC
besides trace amount of CO over i-MC (Figure S5), indicating
Figure 1. (A) Schematic illustration of c-NC and i-NC for CO
B) TEM images of (a1, a2) c-NC and (b1, b2) i-NC viewed along (a1, b1)
110] and (a2, b2) [100] directions. (C) SAXS patterns of c-NC and i-NC. (D)
Raman spectra of c-NC and i-NC. (E) Deconvoluted N1s XPS peaks of c-NC
and i-NC.
2
electroreduction.
(
[
2
the vital role of N-doping played in CO electroreduction.
The N-doped catalysts c-NC and i-NC were tested for the CO
2
The well-resolved peaks on the small-angle X-ray scattering
electroreduction reaction at ambient atmosphere. The cyclic
voltammetry (CV) curves show the electrochemical behaviors of
c-NC and i-NC in Ar and CO saturated 0.1 M KHCO aqueous
2 3
solution (Figure 2A). Obvious reduction peaks appeared at both
CV curves of c-NC (around −0.56 V vs. RHE) and i-NC
(
SAXS) patterns of c-NC and i-NC further illustrated the 2D
hexagonally ordered structure with a space group of P6mm
Figure 1C).[19] We note that the [100] peak of c-NC located at a
smaller angle (q) than that of i-NC, suggesting the larger unit cell
parameter (ɑ ) of c-NC according to the Formulas (1) and (2):
(
0
electrodes (around −0.50 and −0.70 V vs. RHE) in CO
no reduction peak was observed in Ar, implying the reduction of
CO over both c-NC and i-NC electrodes. While the nearly
overlapped CV curves in Ar and CO for both c-MC and i-MC
Figure S7) demonstrated their sluggishness for CO reduction.
, whereas
2
d100 = 2
π
/ q
(1)
2
a0 = 2d100 / 3
(2)
2
in which d100 is the d-spacing value of [100] plane. The specific
surface areas of c-NC and i-NC calculated by the Brunauer–
(
2
In addition, the more positive onset potential for HER and the
larger reduction current in Ar indicated more hydrogen evolved
over i-NC than c-NC (Figure S6). The rectangular CV curve of i-
NC between −0.56 and 0.60 V vs. RHE is ascribed to the
double-layer capacitance.[20]
Results from the potentiostatic electrolysis of CO over c-NC
2
and i-NC are displayed in Figure 2B. The electrolysis potentials
in the range of −0.40 to −1.00 V vs. RHE were applied based on
2
Emmett–Teller (BET) method from N sorption isotherms (Figure
2
-1
S2a) were 631 and 1000 m g , respectively. Using the Barrett–
Joyner–Halenda (BJH) method, the pore size distribution curves
of c-NC and i-NC were obtained, and both exhibited only one
well-resolved peak at the pore size of 5.1 and 3.3 nm,
respectively (Figure S2b). The pore diameter of c-NC (5.1 nm)
was determined by the size of the hexagonally arranged
micelles that were assembled with F127, resol and
dicyandiamide, while that of i-NC (3.3 nm) resulted from the
2
the onset and peak potential for CO reduction. Different from
most of the N-doped carbon materials, mesoporous c-NC and i-
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NC catalysts reproducibly yielded a significant amount of ethanol
To confirm the origin of the product ethanol and the catalytic
activities of c-NC and i-NC, multiple control experiments were
2 2
from CO reduction and H from HER, accompanied by a
negligible amount of CO over c-NC and trace amount of CO
over i-NC. This indicated that mesoporous structures in c-NC
and i-NC facilitated the C-C bond formation, analogous to the
2
performed. Ar was supplied to replace CO in the potentiostatic
electrolysis, which resulted in only hydrogen production at the
same potential range (Figure S10). The isotope-labeling results
NGQD catalysts.[16] In particular, the CO
electroreduction
using 13CO
as the feedstock (see Figure S11 and SI for the
details) ascertained that the product ethanol originated solely
from the electroreduction reaction of the feed CO , and not from
2
2
reaction over c-NC dominantly produced ethanol, with FEs
ranged narrowly between 73 and 77% at the potentials from
2
−
0.40 to −0.56 V. The ethanol FE reached the maximum of 77%
organic contamination or carbonaceous materials. Furthermore,
the inductively coupled plasma (ICP) measurements excluded
the contribution of trace amount of metal impurities to the
catalytic activities of c-NC and i-NC (Table S1 and Figure S5).
Electrochemical impedance spectroscopy (EIS) was
at −0.56 V with an overpotential of 0.63 V. By further decreasing
potentials, HER activity increased over c-NC, resulting in the
gradual decrease of the ethanol FE. We note that the
2
electroreduction of CO to CO over c-NC was always well
suppressed, with the CO FE less than 1.3% throughout the
whole potential range. Thus, the only competitive reactions over
2
performed at −0.56 V vs. RHE in CO to measure the charge
transfer resistance (Rct) for c-NC and i-NC. As shown in Figure
2C, the Rct value of c-NC was as low as 3.8 ohm, even less than
the half of i-NC (8.5 ohm). This implied that many electrons can
be easily transported to the surface of the cylindrical channel of
c-NC. The cylindrical channels were uniformly embedded inside
the carbon framework of c-NC, whose configurations were
considered to be highly beneficial for electron transfer compared
to the crosslinking matrix of carbon nanorods in i-NC.[22]
Furthermore, the specific surface area of c-NC was only about
60% of that of i-NC based on the BET results. Thus, the
c-NC are CO
the situation is more complicated over i-NC, where besides
HER; two routes of CO reduction are present, leading to the
formation of ethanol and CO, respectively. For i-NC,
2
electroreduction to ethanol and HER. In contrast,
2
a
substantial amount of CO was produced with FEs ranging from 5
to 16%, and the maximum ethanol FE reached 44% at −0.50 V
with overpotential of 0.57 V. After that, H formation became
2
dominant (Figure 2B). In addition, both c-NC and i-NC
electrodes delivered rather stable potentiostatic electrolysis at
the potential of −0.56 V (Figure S9), showing the nearly constant
ethanol FE in a duration of 6 h, with a negligible decay in the
current density after electrolysis for 24 h.
2
available surface electron density for CO reduction in c-NC
should be approximately double of that in i-NC.
To shed further light on the origin of the superior
electrocatalytic activity of the N-doped mesoporous carbon for
2
CO reduction to ethanol, density functional theory (DFT)
calculations were performed to examine the possible conversion
pathways (see SI for the computational details). The formation of
the adsorbed intermediates COOH* or CO* by the proton-
electron transfer reaction is the key initial step for CO
2
reduction,[23] and pure carbon and graphitic N sites were
calculated to be highly unfavorable for generating these
intermediates (Figure S12). While both pyridinic and pyrrolic N
2
sites can initiate the adsorption/activation of aqueous CO and
generate the CO* intermediates (Figure 3). The reaction
energies for CO* formation on pyridinic and pyrrolic N sites were
calculated as −1.68 and 0.12 eV, respectively, indicating the
preferential formation of CO* on pyridnic N sites, in agreement
with previous reports.[13,16] Moreover, the CO* intermediates are
stabilized to some extent by the ordered channel surface with
high electron density, hindering the formation of CO as a product.
Thus, the C-C coupling by the dimerization of CO* intermediates
is promoted to form the OC-CO* intermediates with the reaction
energies of −1.31 and −0.34 eV on pyridinic and pyrrolic N sites,
respectively, which indicates that the C-C bond formation is also
favored at pyridinic N sites. The electron-rich surface further
facilitates the subsequent single and multiple proton-electron
transfer reactions to form the intermediate OC-COH* (−1.44 eV
on pyridinic N, and −1.15 eV on pyrrolic N) and the product
ethanol (−4.61 eV on pyridinic N, and -4.51 eV on pyrrolic N),
which are thermodynamically very favorable. The highly active N
sites especially the pyridinic N sites and the high-electron-
density surface of c-NC synergistically contributed to the efficient
and selective production of ethanol (Table S2, Figure S13,S14
and see SI for details).
Figure 2. (A) CV curves of c-NC and i-NC catalysts at a scan rate of 5 mV s-1
in Ar and CO
2 3 2
saturated 0.1 M KHCO aqueous solution. (B) FEs of CO
electroreduction products over c-NC and i-NC catalysts at various applied
potentials. (C) EIS results of c-NC and i-NC performed in CO saturated
2
solution at −0.56 V vs. RHE.
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COMMUNICATION
The key challenge in the selective formation of ethanol from
CO electroreduction lies in promoting C-C bond formation while
2
[1]
M. Asadi, K. Kim, C. Liu, A. V. Addepalli, P. Abbasi, P. Yasaei, P.
Phillips, A. Behranginia, J. M. Cerrato, R. Haasch, P. Zapol, B. Kumar,
R. F. Klie, J. Abiade, L. A. Curtiss, A. Salehi-Khojin, Science 2016, 353,
suppressing CO generation and HER. The absence of C1
products over c-NC implies that the adsorbed CO* intermediates
are stabilized by the cylindrical surface with high electron density,
in favor of the subsequent C-C coupling and proton-electron
transfer reactions. To the best of our knowledge, the
467-470.
[2]
M. Liu, Y. Pang, B. Zhang, P. De Luna, O. Voznyy, J. Xu, X. Zheng, C.
T. Dinh, F. Fan, C. Cao, F. P. G. de Arquer, T. S. Safaei, A. Mepham, A.
Klinkova, E. Kumacheva, Filleter, T. D. Sinton, S. O. Kelley, E. H.
Sargent, Nature 2016, 537, 382-386.
electrocatalytic reduction of CO
2
to ethanol over metal-free
[3]
J. Gong, L. Zhang, Z. J. Zhao, Angew. Chem. Int. Ed. 2017, DOI:
catalysts with nearly 100% selectivity has not yet been reported.
10.1002/anie.201612214;
0.1002/ange.201612214.
Angew.
Chem.
2017,
DOI:
1
[4]
H. Won, H. Shin, J. Koh, J. Chung, H. S. Lee, H. Kim, S. I. Woo, Angew.
Chem. Int. Ed. 2016, 55, 9297-9300; Angew. Chem. 2016, 128, 9443-
9446.
[
5]
6]
J. Rosen, G. S. Hutchings, Q. Lu, S. Rivera, Y. Zhou, D. G. Vlachos, F.
Jiao, ACS Catal. 2015, 5, 4293-4299.
[
A. Loiudice, P. Lobaccaro, E. A. Kamali, T. Thao, B. H. Huang, J. W.
Ager, R. Buonsanti, Angew. Chem. Int. Ed. 2016, 55, 5789-5792;
Angew. Chem. 2016, 128, 5883-5886.
[7]
[8]
[9]
D. Gao, H. Zhou, J. Wang, S. Miao, F. Yang, G. Wang, J. Wang, X.
Bao, J. Am. Chem. Soc. 2015, 137, 4288-4291.
H. Zhang, T. Wang, J. Wang, H. Liu, T. D. Dao, M. Li, G. Liu, X. Meng,
K. Chang, L. Shi, T. Nagao, J. Ye, Adv. Mater. 2016, 28, 3703-3710.
A. S. Varela, N. R. Sahraie, J. Steinberg, W. Ju, H. S. Oh, P. Strasser,
Angew. Chem. Int. Ed. 2015, 54, 10758-10762; Angew. Chem. 2015,
1
27, 10908-10912.
10] Q. Li, W. Zhu, J. Fu, H. Zhang, G. Wu, S. Sun, Nano Energy 2016, 24,
-9.
[
1
[
11] D. D. Zhu, J. L. Liu, S. Z. Qiao, Adv. Mater. 2016, 28, 3423-3452.
12] 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,
[
Figure 3. Calculated reaction energy diagrams for the electroreduction of CO
2
to ethanol over the pyridinic and pyrrolic N sites.
2819.
[
13] J. Wu, R. M. Yadav, M. Liu, P. P. Sharma, C. S. Tiwary, L. Ma, X. Zou,
X. D. Zhou, B. I. Yakobson, J. Lou, P. M. Ajayan, ACS Nano 2015, 9,
5364-5371.
In summary, a metal-free N-doped mesoporous carbon with
ordered cylindrical channel structures was successfully
developed for highly efficient and selective electroreduction of
[14] 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-
7
848.
15] X. Lu, T. H. Tan, Y. H. Ng, R. Amal, Chem. Eur. J. 2016, 22, 11991-
1996.
2
CO to ethanol. The HER side reaction was greatly hindered and
[
[
CO generation was completely suppressed during CO
2
1
electroreduction in aqueous solution at ambient atmosphere.
Our experiments and DFT calculations demonstrated that the
cylindrical structures with their pyridinic/pyrrolic N sites resulted
in high electron density are crucial for CO* dimerization and
ethanol formation. This work will open up an avenue for
developing robust metal-free carbon-based electrocatalysts for
16] J. Wu, S. Ma, J. Sun, J. I. Gold, C. Tiwary, B. Kim, L. Zhu, N. Chopra, I.
N. Odeh, R. Vajtai, A. Z. Yu, R. Luo, J. Lou, G. Ding, P. J. Kenis, P. M.
Ajayan, Nat. Commun. 2016, 7, 13869.
[17] Y. Song, J. Yang, K. Wang, S. Haller, Y. Wang, C. Wang, Y. Xia,
Carbon 2016, 96, 955-964.
[
[
[
18] Y. Song, L. Li, Y. Wang, C. Wang, Z. Guo, Y. Xia, ChemPhysChem
2014, 15, 2084-2091.
2
converting CO to C2 compounds with high selectivity and
19] S. Jun, S. H. Joo, R. Ryoo, M. Kruk, M. Jaroniec, Z. Liu, T. Ohsuna, O.
Terasaki, J. Am. Chem. Soc. 2000, 122, 10712-10713.
efficiency.
20] Y. Song, D. Zhou, Wang, Y. Wang, C. Wang, Y. Xia, New J. Chem.
2
013, 37, 1768-1775.
[21] Y. Liu, S. Chen, X. Quan, H. Yu, J. Am. Chem. Soc. 2015, 137, 11631-
1636.
22] J. K. Hu, M. Noked, E. Gillette, Z. Gui, S. B. Lee, Carbon 2015, 93,
03-914.
Acknowledgements
1
[
[
This work was supported by the Hundred Talents Program of
Chinese Academy of Sciences. We acknowledge the support of
the Ministry of Science and Technology under contract of
9
23] R. Kortlever, J. Shen, K. J. P. Schouten, F. Calle-Vallejo, M. T. M.
Koper, J. Phys. Chem. Lett. 2015, 6, 4073-4082.
2016YFA0202800.
2
Keywords: CO electroreduction • cylindrical channel • C-C
coupling • ethanol • N-doped carbon
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Entry for the Table of Contents (Please choose one layout)
Layout 1:
COMMUNICATION
The C2 product ethanol was
Yanfang Song, Wei Chen,* Chengcheng
Zhao, Shenggang Li, Wei Wei, and
Yuhan Sun*
synthesized
electroreduction over
doped ordered cylindrical mesoporous
carbon. nearly 100% selectivity
from
CO
2
a
nitrogen-
A
Page No. – Page No.
toward ethanol with a high faradaic
efficiency of 77% at -0.56 V vs. RHE
was achieved, which was attributed to
the synergetic effect of the nitrogen
heteroatoms and the cylindrical
channel configurations.
Metal-Free Nitrogen-Doped
Mesoporous Carbon for
Electroreduction of CO to Ethanol
2
Layout 2:
COMMUNICATION
Author(s), Corresponding Author(s)*
((Insert TOC Graphic here))
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Title
Text for Table of Contents
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