Articles
https://doi.org/10.1038/s41929-020-00504-x
Highly active and stable stepped Cu surface
for enhanced electrochemical CO
2
reduction to C
2
H
4
In the format provided by the
authors and unedited
Supplementary information
https://doi.org/10.1038/s41929-020-00504-x
Supplementary Information for
Highly active and stable stepped Cu surface for enhanced electrochemical CO
2
reduction to C
2
H
4
.
Chungseok Choi
1
, Soonho Kwon
2
, Tao Cheng
2,3
, Mingjie Xu
4,5,6,
, Peter Tieu
7
, Changsoo Lee
1,8
,
Jin Cai
1
, Hyuck Mo Lee
8
, Xiaoqing Pan
4,5,9
,
Xiangfeng Duan
10
, William A. Goddard III
2*
, and Yu
Huang
1*
1
Department of Materials Science and Engineering, University of California, Los Angeles, Los
Angeles, California 90095, United States,
2
Department of Applied Physics and Materials
Science, California Institute of Technology, Pasadena, California 91125, United States,
3
Institute
of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based
Functional Materials & Devices, Joint International Research Laboratory of Carbon-Based
Functional Materials and Devices, Soochow University, Suzhou, Jiangsu 215123, People’s
Republic of China,
4
Irvine Material Research Institute (IMRI) and
5
Department of Materials
Science and Engineering, University of California, Irvine, Irvine, California 92697, United
States,
6
Fok Ying Tung Research Institute, The Hong Kong University of Science and
Technology, Guangzhou 511458, P. R. China,
7
Department of Chemistry, University of
California, Irvine, Irvine, California 92697, United States,
8
Department of Materials Science and
Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon,
34141, Republic of Korea,
9
Department of Physics and Astronomy, University of California,
Irvine, Irvine, California 92697, United States,
10
Department of Chemistry and Biochemistry,
University of California, Los Angeles, Los Angeles, California 90095, United States
*
Correspondence to:
yhuang@seas.ucla.edu (Y.H.), wag@caltech.edu (W.A.G.)
This PDF file includes:
Supplementary Figures 1 to 15
Supplementary Tables 1 to 6
Supplementary References
2
Supplementary Figures and Tables
Supplementary Fig. 1
∣
(
a
) PXRD of Syn-CuNWs, (
b
) Size of Syn-CuNWs. The size was
determined by averaging more than 100 NWs. (
c
) PXRD of polycrystalline Cu-foil.
3
Supplementary Fig. 2
∣
The highly stepped surface of A-CuNWs after the activation
process
, (
a
), (
b
) FFT on parts of A-CuNW, (
c
), (
d
) HRTEM images of the surface of A-
CuNW, (
e
) [n(001) x (011)] steps on the surface of A-CuNW, (
f
) [n(100) x (111)] on the
surface of A-CuNW.
4
Supplementary Fig. 3
∣
(
a
) SEI of Syn-CuNWs, (
b
) SEI of A-CuNWs.
5
Supplementary Fig. 4
∣
Pb under-potential deposition (UPD) of Syn-CuNWs (black line) and
A-CuNWs (blue line) to extract ECSA measured in N
2
-saturated 0.1 M HClO
4
+ 0.001 M
Pb(ClO
4
)
2
solution at room temperature. The background current (dotted lines) were
measured in N
2
-saturated 0.1 M HClO
4
.
6
Supplementary Fig. 5
∣
(
a, b
) Nyquist plot of Syn-CuNWs (black) and A-CuNWs (blue).
7
Supplementary Fig. 6
∣
Redox reaction of Syn-CuNWs and A-CuNWs in 0.1 M KOH
at 100
mV/s scan rate
. Cu(100) at ~0.362 V
1-4
, Cu(110) at 0.395
–
0.43 V
1-4
, Cu(111) at ~0.492 V
1-
4
, and A-(hkl) (high energy steps)
3,4
at a negative shift from Cu(100)).
8
Supplementary Fig. 7
∣
OH
-
adsorption of CuNWs after 10 min of activation.
Cu(100) at
~0.362 V (blue color)
1-4
, Cu(110) at 0.395
–
0.43 V (green color)
1-4
.
9
Supplementary Fig. 8
∣
Electrochemical CO
2
RR performance from three independent
measurements.
(
a
) FEs of Cu foil, (
b
) FEs of Syn-CuNW catalysts, (
c
) FEs of A-CuNW
catalysts. Different sizes of the shape indicate different batches of CO
2
RR tests.
10
Supplementary Fig. 9
∣
(
a-d
) Partial current density of Syn-CuNW and A-CuNW catalysts
for each product.