1. Key Laboratory of Aerospace Thermophysics of MIIT, Harbin Institute of Technology, Harbin 150001, China 2. School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China 3. MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China 4. Mechanical Engineering Department, University of Engineering and Technology, Taxila 47050, Pakistan 5. School of Aerospace, Mechanical and Mechatronics Engineering, University of Sydney, Sydney 2006, Australia
Electrochemical CO2 reduction is a sustainable approach in green chemistry that enables the production of valuable chemicals and fuels while mitigating the environmental impact associated with CO2 emissions. Despite its several advantages, this technology suffers from an intrinsically low CO2 solubility in aqueous solutions, resulting in a lower local CO2 concentration near the electrode, which yields lower current densities and restricts product selectivity. Gas diffusion electrodes (GDEs), particularly those with tubular architectures, can solve these issues by increasing the local CO2 concentration and triple-phase interface, providing abundant electroactive sites to achieve superior reaction rates. In this study, robust and self-supported Cu flow-through gas diffusion electrodes (FTGDEs) were synthesized for efficient formate production via electrochemical CO2 reduction. They were further compared with traditional Cu electrodes, and it was found that higher local CO2 concentration due to improved mass transfer, the abundant surface area available for the generation of the triple-phase interface, and the porous structure of Cu FTGDEs enabled high formate Faradaic efficiency (76%) and current density (265 mA·cm–2) at –0.9 V vs. reversible hydrogen electrode (RHE) in 0.5 mol·L–1 KHCO3. The combined phase inversion and calcination process of the Cu FTGDEs helped maintain a stable operation for several hours. The catalytic performance of the Cu FTGDEs was further investigated in a non-gas diffusion configuration to demonstrate the impact of local gas concentration on the activity and performance of electrochemical CO2 reduction. This study demonstrates the potential of flow-through gas-diffusion electrodes to enhance reaction kinetics for the highly efficient and selective reduction of CO2, offering promising applications in sustainable electrochemical processes.
E Ruiz-López , J Gandara-Loe , F Baena-Moreno , T R Reina , J A Odriozola . Electrocatalytic CO2 conversion to C2 products: catalysts design, market perspectives and techno-economic aspects. Renewable & Sustainable Energy Reviews, 2022, 161: 112329 https://doi.org/10.1016/j.rser.2022.112329
2
J J Wang , X P Li , B F Cui , Z Zhang , X F Hu , J Ding , Y D Deng , X P Han , W B Hu . A review of non-noble metal-based electrocatalysts for CO2 electroreduction. Rare Metals, 2021, 40(11): 3019–3037 https://doi.org/10.1007/s12598-021-01736-x
3
A Mustafa , B G Lougou , Y Shuai , Z Wang , S Haseeb-ur-Rehman , W Razzaq , R Wang , F Pan , L Li . Analyzing the electrochemical reduction of CO and CO2 as reactants to C1 and C2 products on copper-based flow-through gas diffusion electrodes. Journal of Environmental Chemical Engineering, 2023, 11(6): 111528 https://doi.org/10.1016/j.jece.2023.111528
4
M Wang , S Zhang , M Li , A Han , X Zhu , Q Ge , J Han , H Wang . Facile synthesis of hierarchical flower-like Ag/Cu2O and Au/Cu2O nanostructures and enhanced catalytic performance in electrochemical reduction of CO2. Frontiers of Chemical Science and Engineering, 2020, 14(5): 813–823 https://doi.org/10.1007/s11705-019-1854-8
5
S Zhang , Q Liu , X Tang , Z Zhou , T Fan , Y You , Q Zhang , S Zhang , J Luo , X Liu . Electrocatalytic reduction of NO to NH3 in ionic liquids by P-doped TiO2 nanotubes. Frontiers of Chemical Science and Engineering, 2023, 17(6): 726–734 https://doi.org/10.1007/s11705-022-2274-8
6
L S Zhan , Y C Wang , M J Liu , X Zhao , J Wu , X Xiong , Y P Lei . Hydropathy modulation on Bi2S3 for enhanced electrocatalytic CO2 reduction. Rare Metals, 2023, 42(3): 806–812 https://doi.org/10.1007/s12598-022-02212-w
7
S Lu , Y Wang , H Xiang , H Lei , B B Xu , L Xing , E H Yu , T X Liu . Mass transfer effect to electrochemical reduction of CO2: electrode, electrocatalyst and electrolyte. Journal of Energy Storage, 2022, 52: 104764 https://doi.org/10.1016/j.est.2022.104764
8
A Mustafa , B G Lougou , Y Shuai , Z Wang , S Razzaq , J Zhao , H Tan . Theoretical insights into the factors affecting the electrochemical reduction of CO2. Sustainable Energy & Fuels, 2020, 4(9): 4352–4369 https://doi.org/10.1039/D0SE00544D
9
H Rabiee , L Ge , X Zhang , S Hu , M Li , Z Yuan . Gas diffusion electrodes (GDEs) for electrochemical reduction of carbon dioxide, carbon monoxide, and dinitrogen to value-added products: a review. Energy & Environmental Science, 2021, 14(4): 1959–2008 https://doi.org/10.1039/D0EE03756G
10
T N Nguyen , C T Dinh . Gas diffusion electrode design for electrochemical carbon dioxide reduction. Chemical Society Reviews, 2020, 49(21): 7488–7504 https://doi.org/10.1039/D0CS00230E
11
S Park , J W Lee , B N Popov . A review of gas diffusion layer in PEM fuel cells: materials and designs. International Journal of Hydrogen Energy, 2012, 37(7): 5850–5865 https://doi.org/10.1016/j.ijhydene.2011.12.148
12
R Omrani , B Shabani . Gas diffusion layer modifications and treatments for improving the performance of proton exchange membrane fuel cells and electrolysers: a review. International Journal of Hydrogen Energy, 2017, 42(47): 28515–28536 https://doi.org/10.1016/j.ijhydene.2017.09.132
13
E H Majlan , D Rohendi , W R Daud , T Husaini , M A Haque . Electrode for proton exchange membrane fuel cells: a review. Renewable & Sustainable Energy Reviews, 2018, 89: 117–134 https://doi.org/10.1016/j.rser.2018.03.007
14
Y C Tan , K B Lee , H Song , J Oh . Modulating local CO2 concentration as a general strategy for enhancing C–C coupling in CO2 electroreduction. Joule, 2020, 4(5): 1104–1120 https://doi.org/10.1016/j.joule.2020.03.013
15
Z Bitar , A Fecant , E Trela-Baudot , S Chardon-Noblat , D Pasquier . Electrocatalytic reduction of carbon dioxide on indium coated gas diffusion electrodes—comparison with indium foil. Applied Catalysis B: Environmental, 2016, 189: 172–180 https://doi.org/10.1016/j.apcatb.2016.02.041
16
J Albo , A Irabien . Cu2O-loaded gas diffusion electrodes for the continuous electrochemical reduction of CO2 to methanol. Journal of Catalysis, 2016, 343: 232–239 https://doi.org/10.1016/j.jcat.2015.11.014
17
J J Li , Z C K Zhang . K+-enhanced electrocatalytic CO2 reduction to multicarbon products in strong acid. Rare Metals, 2022, 41(3): 723–725 https://doi.org/10.1007/s12598-021-01862-6
18
J Wang , J Zou , X Hu , S Ning , X Wang , X Kang , S Chen . Heterostructured intermetallic CuSn catalysts: high performance towards the electrochemical reduction of CO2 to formate. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2019, 7(48): 27514–27521 https://doi.org/10.1039/C9TA11140A
19
K Yang , R Kas , W A Smith , T Burdyny . Role of the carbon-based gas diffusion layer on flooding in a gas diffusion electrode cell for electrochemical CO2 reduction. ACS Energy Letters, 2021, 6(1): 33–40 https://doi.org/10.1021/acsenergylett.0c02184
20
H R Jhong , F R Brushett , P J Kenis . The effects of catalyst layer deposition methodology on electrode performance. Advanced Energy Materials, 2013, 3(5): 589–599 https://doi.org/10.1002/aenm.201200759
21
B Laoun , H A Kasat , R Ahmad , A M Kannan . Gas diffusion layer development using design of experiments for the optimization of a proton exchange membrane fuel cell performance. Energy, 2018, 151: 689–695 https://doi.org/10.1016/j.energy.2018.03.096
22
D Higgins , C Hahn , C Xiang , T F Jaramillo , A Z Weber . Gas-diffusion electrodes for carbon dioxide reduction: a new paradigm. ACS Energy Letters, 2019, 4(1): 317–324 https://doi.org/10.1021/acsenergylett.8b02035
23
M C Monteiro , M F Philips , K J Schouten , M T Koper . Efficiency and selectivity of CO2 reduction to CO on gold gas diffusion electrodes in acidic media. Nature Communications, 2021, 12(1): 4943 https://doi.org/10.1038/s41467-021-24936-6
24
K Jiang , R B Sandberg , A J Akey , X Liu , D C Bell , J K Nørskov , K Chan , H Wang . Metal ion cycling of Cu foil for selective C–C coupling in electrochemical CO2 reduction. Nature Catalysis, 2018, 1(2): 111–119 https://doi.org/10.1038/s41929-017-0009-x
25
X Hou , Y Cai , D Zhang , L Li , X Zhang , Z Zhu , L Peng , Y Liu , J Qiao . 3D core–shell porous-structured Cu@Sn hybrid electrodes with unprecedented selective CO2-into-formate electroreduction achieving 100%. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2019, 7(7): 3197–3205 https://doi.org/10.1039/C8TA10650A
26
A A Peterson , F Abild-Pedersen , F Studt , J Rossmeisl , J K Nørskov . How copper catalyzes the electroreduction of carbon dioxide into hydrocarbon fuels. Energy & Environmental Science, 2010, 3(9): 1311–1315 https://doi.org/10.1039/c0ee00071j
27
W J Durand , A A Peterson , F Studt , F Abild-Pedersen , J K Nørskov . Structure effects on the energetics of the electrochemical reduction of CO2 by copper surfaces. Surface Science, 2011, 605(15-16): 1354–1359 https://doi.org/10.1016/j.susc.2011.04.028
28
S Nitopi , E Bertheussen , S B Scott , X Liu , A K Engstfeld , S Horch , B Seger , I E Stephens , K Chan , C Hahn . et al.. Progress and perspectives of electrochemical CO2 reduction on copper in aqueous electrolyte. Chemical Reviews, 2019, 119(12): 7610–7672 https://doi.org/10.1021/acs.chemrev.8b00705
29
J Zhao , S Xue , J Barber , Y Zhou , J Meng , X Ke . An overview of Cu-based heterogeneous electrocatalysts for CO2 reduction. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2020, 8(9): 4700–4734 https://doi.org/10.1039/C9TA11778D
30
R Reske , H Mistry , F Behafarid , B Roldan Cuenya , P Strasser . Particle size effects in the catalytic electroreduction of CO2 on Cu nanoparticles. Journal of the American Chemical Society, 2014, 136(19): 6978–6986 https://doi.org/10.1021/ja500328k
31
N J Firet , T Burdyny , N T Nesbitt , S Chandrashekar , A Longo , W A Smith . Copper and silver gas diffusion electrodes performing CO2 reduction studied through operando X-ray absorption spectroscopy. Catalysis Science & Technology, 2020, 10(17): 5870–5885 https://doi.org/10.1039/D0CY01267J
32
S Paul , Y L Kao , L Ni , R Ehnert , I Herrmann-Geppert , R van de Krol , R W Stark , W Jaegermann , U I Kramm , P Bogdanoff . Influence of the metal center in M–N–C catalysts on the CO2 reduction reaction on gas diffusion electrodes. ACS Catalysis, 2021, 11(9): 5850–5864 https://doi.org/10.1021/acscatal.0c05596
33
L C Weng , A T Bell , A Z Weber . Modeling gas-diffusion electrodes for CO2 reduction. Physical Chemistry Chemical Physics, 2018, 20(25): 16973–16984 https://doi.org/10.1039/C8CP01319E
34
M Abdinejad , M K Motlagh , M Noroozifar , H B Kraatz . Electroreduction of carbon dioxide to formate using highly efficient bimetallic Sn-Pd aerogels. Materials Advances, 2022, 3(2): 1224–1230 https://doi.org/10.1039/D1MA01057C
35
C Zhu , Y Song , X Dong , G Li , A Chen , W Chen , G Wu , S Li , W Wei , Y Sun . Ampere-level CO2 reduction to multicarbon products over a copper gas penetration electrode. Energy & Environmental Science, 2022, 15(12): 5391–5404 https://doi.org/10.1039/D2EE02121H
36
S Ikeda , K Ito , H Noda . Electrochemical reduction of carbon dioxide using gas diffusion electrodes loaded with fine catalysts. American Institute of Physics: AIP Conference Proceedings, 2009, 1136(1): 108–113 https://doi.org/10.1063/1.3160110
37
H Yang , S Li , Q Xu . Efficient strategies for promoting the electrochemical reduction of CO2 to C2+ products over Cu-based catalysts. Chinese Journal of Catalysis, 2023, 48: 32–65 https://doi.org/10.1016/S1872-2067(23)64429-8
38
A S Varela , M Kroschel , T Reier , P Strasser . Controlling the selectivity of CO2 electroreduction on copper: the effect of the electrolyte concentration and the importance of the local pH. Catalysis Today, 2016, 260: 8–13 https://doi.org/10.1016/j.cattod.2015.06.009
39
A Klinkova , P De Luna , C T Dinh , O Voznyy , E M Larin , E Kumacheva , E H Sargent . Rational design of efficient palladium catalysts for electroreduction of carbon dioxide to formate. ACS Catalysis, 2016, 6(12): 8115–8120 https://doi.org/10.1021/acscatal.6b01719
40
F Li , L Chen , G P Knowles , D R MacFarlane , J Zhang . Hierarchical mesoporous SnO2 nanosheets on carbon cloth: a robust and flexible electrocatalyst for CO2 reduction with high efficiency and selectivity. Angewandte Chemie International Edition, 2017, 56(2): 505–509 https://doi.org/10.1002/anie.201608279
41
Y Huang , Y Deng , A D Handoko , G K Goh , B S Yeo . Rational design of sulfur‐doped copper catalysts for the selective electroreduction of carbon dioxide to formate. ChemSusChem, 2018, 11(1): 320–326 https://doi.org/10.1002/cssc.201701314
42
T Shinagawa , G O Larrazábal , A J Martín , F Krumeich , J Perez-Ramirez . Sulfur-modified copper catalysts for the electrochemical reduction of carbon dioxide to formate. ACS Catalysis, 2018, 8(2): 837–844 https://doi.org/10.1021/acscatal.7b03161
43
M Duarte , B De Mot , J Hereijgers , T Breugelmans . Electrochemical reduction of CO2: effect of convective CO2 supply in gas diffusion electrodes. ChemElectroChem, 2019, 6(22): 5596–5602 https://doi.org/10.1002/celc.201901454
44
L de Sousa , N E Benes , G Mul . Evaluating the effects of membranes, cell designs, and flow configurations on the performance of Cu-GDEs in converting CO2 to CO. ACS ES&T Engineering, 2022, 2(11): 2034–2042 https://doi.org/10.1021/acsestengg.2c00137
45
G Marcandalli , A Goyal , M T Koper . Electrolyte effects on the faradaic efficiency of CO2 reduction to CO on a gold electrode. ACS Catalysis, 2021, 11(9): 4936–4945 https://doi.org/10.1021/acscatal.1c00272
46
K Ye , G Zhang , X Y Ma , C Deng , X Huang , C Yuan , G Meng , W B Cai , K Jiang . Resolving local reaction environment toward an optimized CO2-to-CO conversion performance. Energy & Environmental Science, 2022, 15(2): 749–759 https://doi.org/10.1039/D1EE02966E
47
M Jouny , W Luc , F Jiao . High-rate electroreduction of carbon monoxide to multi-carbon products. Nature Catalysis, 2018, 1(10): 748–755 https://doi.org/10.1038/s41929-018-0133-2
48
L Peng , Y Wang , Y Wang , N Xu , W Lou , P Liu , D Cai , H Huang , J Qiao . Separated growth of Bi-Cu bimetallic electrocatalysts on defective copper foam for highly converting CO2 to formate with alkaline anion-exchange membrane beyond KHCO3 electrolyte. Applied Catalysis B: Environmental, 2021, 288: 120003 https://doi.org/10.1016/j.apcatb.2021.120003
49
K Ye , G Zhang , B Ni , L Guo , C Deng , X Zhuang , C Zhao , W B Cai , K Jiang . Steering CO2 electrolysis selectivity by modulating the local reaction environment: an online DEMS approach for Cu electrodes. eScience, 2023, 3(4): 100143 https://doi.org/10.1016/j.esci.2023.100143
50
G Zhang , K Ye , B Ni , K Jiang . Steering the products distribution of CO2 electrolysis: a perspective on extrinsic tuning knobs. Chem Catalysis, 2023, 3(9): 100746 https://doi.org/10.1016/j.checat.2023.100746
