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

RIGHTS & PERMISSIONS

Higher Education Press