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Type |
Oral Presentation |
Area |
Oral Presentation for Young Scholars in Physical Chemistry |
Room No. |
Room 324A |
Time |
THU 10:24-: |
Code |
PHYS.O-8 |
Subject |
Unveiling C1, C2 and C3 mechanism of electrochemical CO2 reduction at sulfur vacancy of MoS2: Ab initio study |
Authors |
Sungwoo Kang, Seungwu Han* Materials Science and Engineering, Seoul National University, Korea |
Abstract |
MoS2 is receiving large attention as a promising electrochemical carbon dioxide reduction (CO2R) catalyst which shows good selectivity and current density at edge site in ionic liquid [1-3]. Recently, Francis et al. reported that CO2R is occurred at basal plane of MoS2 which produces 1-propanol as a major product [4]. In this work, we investigate the catalytic performance of CO2R at sulfur vacancy (Vs) of MoS2, which has been recently reported as an active site for HER [5], by density functional theory. Possible reaction paths are investigated by modifying computational hydrogen electrode model as considering charged states of intermediates [6]. We first calculated pathways for C1 product: formic acid, formaldehyde, methane and methanol are identified as possible products at potential of -0.4 V vs RHE. In addition, In addition, C2 products (ethanol, ethylene glycol) and C3 products (1-propanol, 1,3-propylene glycol) were possibly evolved at the same potential with C1 products (-0.4 V vs RHE). Our results well explain recent experiment on CO2R at single-crystal and thin film MoS2 electrode that 1-propanol is evolved at -0.59 V vs RHE as a major product. Minor products were produced such as formate, ethylene glycol, t-butanol, methanol and methane at the same potential [4] which was also in agreement with our results. Finally, based on verified mechanism, we suggest cascade structure of Vs-MoS2 with other catalysts, which produces HCHO as a major product, to enhance selectivity of CO2R vs HER at Vs-MoS2.
[1] Nat. Commun., 2014, 5, 4470.
[2] Science, 2016, 242, 467.
[3] ACS Nano, 2018, 11, 453.
[4] Chem. Mater., 2018, 30, 4902.
[5] Nat. Mater., 2016, 15, 48–53.
[6] ACS Catal., 2018, 8, 4508.
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E-mail |
kang1717@snu.ac.kr |
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