Combined effects of sea urchin-like structure and mixed Cu⁺/Cu⁰ states on promoting C₂ formation in electrocatalytic CO₂ reduction

Abstract

Surface engineering and Cu valence regulation are essential factors in improving the C₂ selectivity during the electrochemical reduction of CO₂. Herein, we present a sea urchin-like CuO/Cu₂O catalyst derived from rhombic dodecahedra Cu₂O through one-step oxidation/etching method where the mixed Cu⁺/Cu⁰ states are formed via in situ reduction during electrocatalysis. The combined effects of the morphology and the mixed Cu⁺/Cu⁰ states on C–C coupling are evaluated by the Faradaic efficiency of C₂ and the C₂/C₁ ratio obtained in an H-cell. R-CuO/Cu₂O exhibited 49.5% Faradaic efficiency of C₂ with a C₂/C₁ ratio of 3.1 at −1.4 V vs. reversible hydrogen electrode, which are 1.5 and 3.2 times higher than those of R-Cu₂O, respectively. Using a flow-cell, 68.0% Faradaic efficiency of C₂ is achieved at a current density of 500 mA·cm⁻². The formation of the mixed Cu⁺/Cu⁰ states was confirmed by in situ Raman spectra. Additionally, the sea urchin-like structure provides more active sites and enables faster electron transfer. As a result, the excellent C₂ production on R-CuO/Cu₂O is primarily attributed to the synergistic effects of the sea urchin-like structure and the stable mixed Cu⁺/Cu⁰ states. Therefore, this work presents an integrated strategy for developing Cu-based electrocatalysts for C₂ production through electrochemical CO₂ reduction.

Graphical abstract

Keywords

CO₂ electrolysis / sea urchin-like structure / Cu⁺/Cu⁰ / C₂ products

References

[1] Zhao Y J , Wang X Y , Sang X H , Zheng S X , Yang B , Lei L C , Hou Y , Li Z J . Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective CO₂ electrolysis. Frontiers of Chemical Science and Engineering, 2022, 16(12): 1772–1781

[2] Woldu A R , Huang Z , Zhao P , Hu L , Astruc D . Electrochemical CO₂ reduction (CO₂RR) to multi-carbon products over copper-based catalysts. Coordination Chemistry Reviews, 2022, 454: 214340

[3] Wang J , Wang H , Han Z , Han J . Electrodeposited porous Pb electrode with improved electrocatalytic performance for the electroreduction of CO₂ to formic acid. Frontiers of Chemical Science and Engineering, 2016, 9(1): 57–63

[4] Qu J P , Cao X J , Gao L , Li J Y , Li L , Xie Y H , Zhao Y F , Zhang J Q , Wu M H , Liu H . Electrochemical carbon dioxide reduction to ethylene: from mechanistic understanding to catalyst surface engineering. Nano-Micro Letters, 2023, 15(1): 178

[5] Yao D , Tang C , Vasileff A , Zhi X , Jiao Y , Qiao S Z . The controllable reconstruction of Bi-MOFs for electrochemical CO₂ reduction through electrolyte and potential mediation. Angewandte Chemie International Edition, 2021, 60(33): 18178–18184

[6] Saha P , Amanullah S , Dey A . Selectivity in electrochemical CO₂ reduction. Accounts of Chemical Research, 2022, 55(2): 134–144

[7] Zhu J X , Li J T , Lu R H , Yu R H , Zhao S Y , Li C B , Lv L , Xia L X , Chen X , Cai W . . Surface passivation for highly active, selective, stable, and scalable CO₂ electroreduction. Nature Communications, 2023, 14(1): 4670

[8] Chen P C , Chen C B , Yang Y , Maulana A L , Jin J B , Feijoo J L , Yang P D . Chemical and structural evolution of AgCu catalysts in electrochemical CO₂ reduction. Journal of the American Chemical Society, 2023, 145(18): 10116–10125

[9] Li S M , Yan X D , Tang J Q , Cao D X , Sun X L , Tian G L , Tang X K , Guo H F , Wu Q Y , Sun J . . Cu₂₆ nanoclusters with quintuple ligand shells for CO₂ electrocatalytic reduction. Chemistry of Materials, 2023, 35(15): 6123–6132

[10] Wang M Y , Zhang S B , Li M , Han A G , Zhu X L , Ge Q F , Han J Y , Wang H . 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

[11] Wang J L , Tan H Y , Zhu Y P , Chu H , Chen H M . Linking the dynamic chemical state of catalysts with the product profile of electrocatalytic CO₂ reduction. Angewandte Chemie, 2021, 133(32): 17394–17407

[12] Zhang Q , Wang J , Guo F , He G , Yang X , Li W , Xu J , Yin Z . Nitrogen cold plasma treatment stabilizes Cu⁰/Cu⁺ electrocatalysts to enhance CO₂ to C₂ conversion. Journal of Energy Chemistry, 2023, 84: 321–328

[13] Yuan X , Chen S , Cheng D , Li L , Zhu W , Zhong D , Zhao Z J , Li J , Wang T , Gong J . Controllable Cu⁰–Cu⁺ sites for electrocatalytic reduction of carbon dioxide. Angewandte Chemie International Edition, 2021, 60(28): 15344–15347

[14] Sun L R , Han J Y , Ge Q F , Zhu X L , Wang H . Understanding the role of Cu⁺/Cu⁰ sites at Cu₂O based catalysts in ethanol production from CO₂ electroreduction—a DFT study. RSC Advances, 2022, 12(30): 19394–19401

[15] Wang S N , Wang D , Tian B Q , Gao X X , Han L , Zhong Y , Song S C , Wang Z L , Li Y P , Gui J N . . Synergistic Cu⁺/Cu⁰ on Cu₂O–Cu interfaces for efficient and selective C₂₊ production in electrocatalytic CO₂ conversion. Science China Materials, 2023, 66(5): 1801–1809

[16] He T W , Tang C , Puente Santiago A R , Luque R , Pan H , Du A J . Tuning CO binding strength via engineering the copper/borophene interface for highly efficient conversion of CO into ethanol. Journal of Materials Chemistry A, 2021, 9(22): 13192–13199

[17] Kim C , Cho K M , Park K , Kim J Y , Yun G T , Toma F M , Gereige I , Jung H T . Cu/Cu₂O interconnected porous aerogel catalyst for highly productive electrosynthesis of ethanol from CO₂. Advanced Functional Materials, 2021, 31(32): 2102142

[18] Liu W , Zhai P B , Li A , Wei B , Si K P , Wei Y , Wang X G , Zhu G D , Chen Q , Gu X K . . Electrochemical CO₂ reduction to ethylene by ultrathin CuO nanoplate arrays. Nature Communications, 2022, 13(1): 1877

[19] Jiang K , Huang Y F , Zeng G S , Toma F M , Goddard W A III , Bell A T . Effects of surface roughness on the electrochemical reduction of CO₂ over Cu. ACS Energy Letters, 2020, 5(4): 1206–1214

[20] Sang J Q , Wei P F , Liu T F , Lv H F , Ni X M , Gao D F , Zhang J W , Li H F , Zang Y P , Yang F . . A reconstructed Cu₂P₂O₇ catalyst for selective CO₂ electroreduction to multicarbon products. Angewandte Chemie International Edition, 2021, 61(5): e202114238

[21] Li W , Feng X L , Zhang Z , Jin X , Liu D P , Zhang Y . A controllable surface etching strategy for well-defined spiny yolk@shell CuO@CeO₂ cubes and their catalytic performance boost. Advanced Functional Materials, 2018, 28(49): 1802559

[22] Hua Q , Chen K , Chang S J , Ma Y S , Huang W X . Crystal plane-dependent compositional and structural evolution of uniform Cu₂O nanocrystals in aqueous ammonia solutions. Journal of Physical Chemistry C, 2011, 115(42): 20618–20627

[23] Scholten F , Nguyen K L C , Bruce J P , Heyde M , Roldan Cuenya B . Identifying structure-selectivity correlations in the electrochemical reduction of CO₂: a comparison of well-ordered atomically clean and chemically etched copper single-crystal surfaces. Angewandte Chemie International Edition, 2021, 60(35): 19169–19175

[24] Yang P P , Zhang X L , Gao F Y , Zheng Y R , Niu Z Z , Yu X , Liu R , Wu Z Z , Qin S , Chi L P . . Protecting copper oxidation state via intermediate confinement for selective CO₂ electroreduction to C₂₊ fuels. Journal of the American Chemical Society, 2020, 142(13): 6400–6408

[25] Huang W C , Lyu L M , Yang Y C , Huang M H . Synthesis of Cu₂O nanocrystals from cubic to rhombic dodecahedral structures and their comparative photocatalytic activity. Journal of the American Chemical Society, 2011, 134(2): 1261–1267

[26] Huang J J , Chen Z , Cai J M , Jin Y Z , Wang T , Wang J H . Activating copper oxide for stable electrocatalytic ammonia oxidation reaction via in-situ introducing oxygen vacancies. Nano Research, 2022, 15(7): 5987–5994

[27] Yan X , Chen C , Wu Y , Liu S , Chen Y , Feng R , Zhang J , Han B . Efficient electroreduction of CO₂ to C₂₊ products on CeO₂ modified CuO. Chemical Science, 2021, 12(19): 6638–6645

[28] Alabsi M H , Wang X L , Zheng P , Ramirez A , Duan A J , Xu C M , Huang K W . Screening and design of active metals on dendritic mesoporous Ce_0.3Zr_0.7O₂ for efficient CO₂ hydrogenation to methanol. Fuel, 2022, 317: 123471

[29] Wang X Q , Chen Q , Zhou Y J , Li H M , Fu J W , Liu M . Cu-based bimetallic catalysts for CO₂ reduction reaction. Advanced Sensor and Energy Materials, 2022, 1(3): 100023

[30] Luo H Q , Li B , Ma J G , Cheng P . Surface modification of Nano-Cu₂O for controlling CO₂ electrochemical reduction to ethylene and syngas. Angewandte Chemie International Edition, 2022, 61(11): e202116736

[31] Chou T C , Chang C C , Yu H L , Yu W Y , Dong C L , Velasco Vélez J J , Chuang C H , Chen L C , Lee J F , Chen J M . . Controlling the oxidation state of the Cu electrode and reaction intermediates for electrochemical CO₂ reduction to ethylene. Journal of the American Chemical Society, 2020, 142(6): 2857–2867

[32] Wu Z Z , Zhang X L , Niu Z Z , Gao F Y , Yang P P , Chi L P , Shi L , Wei W S , Liu R , Chen Z . . Identification of Cu(100)/Cu(111) interfaces as superior active sites for CO dimerization during CO₂ electroreduction. Journal of the American Chemical Society, 2021, 144(1): 259–269

[33] Park D G , Choi J W , Chun H , Jang H S , Lee H , Choi W H , Moon B C , Kim K H , Kim M G , Choi K M . . Increasing CO binding energy and defects by preserving Cu oxidation state via O₂-plasma-assisted N doping on CuO enables high C₂₊ selectivity and long-term stability in electrochemical CO₂ reduction. ACS Catalysis, 2023, 13(13): 9222–9233

[34] Fang M W , Wang M L , Wang Z W , Zhang Z X , Zhou H C , Dai L M , Zhu Y , Jiang L . Hydrophobic, ultrastable Cu^δ+ for robust CO₂ electroreduction to C₂ products at ampere-current levels. Journal of the American Chemical Society, 2023, 145(20): 11323–11332

[35] Wordsworth J , Benedetti T M , Somerville S V , Schuhmann W , Tilley R D , Gooding J J . The influence of nanoconfinement on electrocatalysis. Angewandte Chemie International Edition, 2022, 61(28): e202200755

[36] Lee S , Kim D , Lee J . Electrocatalytic production of C₃–C₄ compounds by conversion of CO₂ on a chloride-induced Bi-phasic Cu₂O–Cu catalyst. Angewandte Chemie International Edition, 2015, 54(49): 14701–14705

[37] Kuang S Y , Li M L , Xia R , Xing L , Su Y Q , Fan Q , Liu J P , Hensen E J M , Ma X B , Zhang S . Stable surface-anchored Cu nanocubes for CO₂ electroreduction to ethylene. ACS Applied Nano Materials, 2020, 3(8): 8328–8334

[38] Yang W , Liu H , Qi Y , Li Y , Cui Y , Yu L , Cui X , Deng D . Boosting C–C coupling to multicarbon products via high-pressure CO electroreduction. Journal of Energy Chemistry, 2023, 85: 102–107

[39] Sebastián-Pascual P , Escudero-Escribano M . Addressing the interfacial properties for CO electroreduction on Cu with cyclic voltammetry. ACS Energy Letters, 2019, 5(1): 130–135

[40] Choi C , Kwon S , Cheng T , Xu M J , Tieu P , Lee C , Cai J , Lee H M , Pan X Q , Duan X F . . Highly active and stable stepped Cu surface for enhanced electrochemical CO₂ reduction to C₂H₄. Nature Catalysis, 2020, 3(10): 804–812

[41] Jiang Y W , Wang X Y , Duan D L , He C H , Ma J , Zhang W Q , Liu H J , Long R , Li Z B , Kong T T . . Structural reconstruction of Cu₂O superparticles toward electrocatalytic CO₂ reduction with high C₂₊ products selectivity. Advanced Science, 2022, 9(16): 2105292

[42] Liu P , Hensen E J M . Highly efficient and robust Au/MgCuCr₂O₄ catalyst for gas-phase oxidation of ethanol to acetaldehyde. Journal of the American Chemical Society, 2013, 135(38): 14032–14035

[43] Lyu Z H , Zhu S Q , Xie M H , Zhang Y , Chen Z T , Chen R H , Tian M K , Chi M F , Shao M H , Xia Y N . Controlling the surface oxidation of Cu nanowires improves their catalytic selectivity and stability toward C₂₊ products in CO₂ reduction. Angewandte Chemie International Edition, 2021, 60(4): 1909–1915

[44] Xie M C , Shen Y , Ma W C , Wei D Y , Zhang B , Wang Z H , Wang Y H , Zhang Q H , Xie S J , Wang C . . Fast screening for copper-based bimetallic electrocatalysts: efficient electrocatalytic reduction of CO₂ to C₂₊ products on magnesium-modified copper. Angewandte Chemie International Edition, 2022, 61(51): e202213423

[45] Wang Y , Zhao J K , Cao C , Ding J , Wang R Y , Zeng J , Bao J , Liu B . Amino-functionalized Cu for efficient electrochemical reduction of CO to acetate. ACS Catalysis, 2023, 13(6): 3532–3540

[46] Duan G Y , Li X Q , Ding G R , Han L J , Xu B H , Zhang S J . Highly efficient electrocatalytic CO₂ reduction to C₂₊ products on a poly(ionic liquid)-based Cu⁰–Cu^I tandem catalyst. Angewandte Chemie International Edition, 2022, 61(9): e202110657

[47] Zhang J , Wang Y , Li Z , Xia S , Cai R , Ma L , Zhang T , Ackley J , Yang S , Wu Y . . Grain boundary-derived Cu⁺/Cu⁰ interfaces in CuO nanosheets for low overpotential carbon dioxide electroreduction to ethylene. Advanced Science, 2022, 9(21): 2200454

[48] Lei Q , Huang L , Yin J , Davaasuren B , Yuan Y , Dong X , Wu Z , Wang X , Yao K , Lu X . . Structural evolution and strain generation of derived-Cu catalysts during CO₂ electroreduction. Nature Communications, 2022, 13(1): 4857

[49] Chen S , Li Y , Bu Z , Yang F , Luo J , An Q , Zeng Z , Wang J , Deng S . Boosting CO₂-to-CO conversion on a robust single-atom copper decorated carbon catalyst by enhancing intermediate binding strength. Journal of Materials Chemistry A, 2021, 9(3): 1705–1712

[50] Liu H , Miao B Y , Chuai H , Chen X , Zhang S , Ma X B . Nanoporous tin oxides for efficient electrochemical CO₂ reduction to formate. Green Chemical Engineering, 2022, 3(2): 138–145

Competing interests

The authors declare that they have no competing interests.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 22178266). We are grateful to Donghai Mei group of Tiangong University for providing in situ Raman spectroscopy tests. We thank Prof. Xiaolei Wang and Dr. Mahrima Majid of University of Alberta for polishing English language of the full text.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11705-024-2393-5 and is accessible for authorized users.

RIGHTS & PERMISSIONS

2024 Higher Education Press