Metal-Organic Framework-Derived Partially Oxidized Cu Electrocatalysts for Efficient CO₂ Reduction Reaction Toward C₂₊ Products

Abstract

Cu-based metal-organic frameworks (Cu-MOFs) electrocatalysts are promising for CO₂ reduction reactions (CO₂RR) to produce valuable C₂₊ products. However, designing suitable active sites in Cu-MOFs remains challenging due to their inherent structural instability during CO₂RR. Here we propose a synergistic strategy through thermal annealing and electrochemical-activation process for in-situ reconstruction of the pre-designed Cu-MOFs to produce abundant partially oxidized Cu (Cu^δ+) active species. The optimized MOF-derived Cu^δ+ electrocatalyst demonstrates a highly selective production of C₂₊ products, with the Faradaic Efficiency (FE) of 78 ± 2% and a partial current density of −46 mA cm⁻² at −1.06 V_RHE in a standard H-type cell. Our findings reveal that the optimized Cu^δ+-rich surface remains stable during electrolysis and enhances surface charge transfer, leading to an increase in the concentration of *CO intermediates, thereby highly selectively producing C₂₊ compounds. This study advances the controllable formation of MOF-derived Cu^δ+-rich surfaces and strengthens the understanding of their catalytic role in CO₂RR for C₂₊ products.

Keywords

CO₂RR / Cu-based MOF catalyst / high C₂₊ selectivity / MOF-derived Cu⁺ / Quasi in-situ XPS

References

[1] C. F. Shih, T. Zhang, J. Li, and C. Bai, “Powering the Future With Liquid Sunshine,” Joule 2, no. 10 (2018): 1925-1949.

[2] A. Goeppert, M. Czaun, G. K. Surya Prakash, and G. A. Olah, “Air as the Renewable Carbon Source of the Future: An Overview of CO₂ Capture From the Atmosphere,” Energy & Environmental Science 5, no. 7 (2012): 7833-7853.

[3] S. Nitopi, E. Bertheussen, S. B. Scott, et al., “Progress and Perspectives of Electrochemical CO₂ Reduction on Copper in Aqueous Electrolyte,” Chemical Reviews 119, no. 12 (2019): 7610-7672.

[4] D. Gao, R. M. Arán-Ais, H. S. Jeon, and B. Roldan Cuenya, “Rational Catalyst and Electrolyte Design for CO₂ Electroreduction Towards Multicarbon Products,” Nature Catalysis 2, no. 3 (2019): 198-210.

[5] J. H. Montoya, C. Shi, K. Chan, and J. K. Nørskov, “Theoretical Insights Into a CO Dimerization Mechanism in CO₂ Electroreduction,” Journal of Physical Chemistry Letters 6, no. 11 (2015): 2032-2037.

[6] D. U. Nielsen, X.-M. Hu, K. Daasbjerg, and T. Skrydstrup, “Chemically and Electrochemically Catalysed Conversion of CO₂ to CO With Follow-Up Utilization to Value-Added Chemicals,” Nature Catalysis 1, no. 4 (2018): 244-254.

[7] Y. Hori, I. Takahashi, O. Koga, and N. Hoshi, “Electrochemical Reduction of Carbon Dioxide at Various Series of Copper Single Crystal Electrodes,” Journal of Molecular Catalysis A: Chemical 199, no. 1-2 (2003): 39-47.

[8] Y. Hori, A. Murata, and R. Takahashi, “Formation of Hydrocarbons in the Electrochemical Reduction of Carbon Dioxide at a Copper Electrode In Aqueous Solution,” Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases 85, no. 8 (1989): 2309-2326.

[9] W. Zhang, C. Huang, Q. Xiao, et al., “Atypical Oxygen-Bearing Copper Boosts Ethylene Selectivity Toward Electrocatalytic CO₂ Reduction,” Journal of the American Chemical Society 142, no. 26 (2020): 11417-11427.

[10] Z. Chen, T. Wang, B. Liu, et al., “Grain-Boundary-Rich Copper for Efficient Solar-Driven Electrochemical CO₂ Reduction to Ethylene and Ethanol,” Journal of the American Chemical Society 142, no. 15 (2020): 6878-6883.

[11] D. Zhong, Z. J. Zhao, Q. Zhao, et al., “Coupling of Cu(100) and (110) Facets Promotes Carbon Dioxide Conversion to Hydrocarbons and Alcohols,” Angewandte Chemie International Edition 60, no. 9 (2021): 4879-4885.

[12] Z. Lyu, S. Zhu, M. Xie, et al., “Controlling the Surface Oxidation of Cu Nanowires Improves Their Catalytic Selectivity and Stability Toward C₂₊ Products in CO₂ Reduction,” Angewandte Chemie International Edition 60, no. 4 (2021): 1909-1915.

[13] C. Zhan, F. Dattila, C. Rettenmaier, et al., “Revealing the CO Coverage-Driven C-C Coupling Mechanism for Electrochemical CO₂ Reduction on Cu₂O Nanocubes via Operando Raman Spectroscopy,” ACS Catalysis 11, no. 13 (2021): 7694-7701.

[14] M. Zheng, P. Wang, X. Zhi, et al., “Electrocatalytic CO₂-to-C₂₊ With Ampere-Level Current on Heteroatom-Engineered Copper via Tuning* CO Intermediate Coverage,” Journal of the American Chemical Society 144, no. 32 (2022): 14936-14944.

[15] Z.-Z. Wu, F.-Y. Gao, and M.-R. Gao, “Regulating the Oxidation State of Nanomaterials for Electrocatalytic CO₂ Reduction,” Energy & Environmental Science 14, no. 3 (2021): 1121-1139.

[16] H. Li, T. Liu, P. Wei, et al., “High-Rate CO₂ Electroreduction to C₂₊ Products Over a Copper-Copper Iodide Catalyst,” Angewandte Chemie International Edition 60, no. 26 (2021): 14329-14333.

[17] H. Mistry, A. S. Varela, C. S. Bonifacio, et al., “Highly Selective Plasma-Activated Copper Catalysts for Carbon Dioxide Reduction to Ethylene,” Nature Communications 7, no. 1 (2016): 12123.

[18] X. Tan, C. Yu, C. Zhao, et al., “Restructuring of Cu₂O to Cu₂O@Cu-Metal-Organic Frameworks for Selective Electrochemical Reduction of CO₂,” ACS Applied Materials & Interfaces 11, no. 10 (2019): 9904-9910.

[19] S. Zhang, K. Chen, L. Zhu, et al., “Direct Growth of Two-Dimensional Phthalocyanine-Based COF on Cu-MOF to Construct a Photoelectrochemical-Electrochemical Dual-Mode Biosensing Platform for High-Efficiency Determination of Cr(III),” Dalton Transactions 50, no. 40 (2021): 14285-14295.

[20] J. Yan, H. Wang, B. Jin, M. Zeng, and R. Peng, “Cu-MOF Derived Cu/Cu₂O/C Nanocomposites for the Efficient Thermal Decomposition of Ammonium Perchlorate,” Journal of Solid State Chemistry 297 (2021): 122060.

[21] S. Wang, Z. Gao, G. Song, et al., “Copper Oxide Hierarchical Morphology Derived From MOF Precursors for Enhancing Ethanol Vapor Sensing Performance,” Journal of Materials Chemistry C 8, no. 28 (2020): 9671-9677.

[22] Y. N. Gong, L. Jiao, Y. Qian, et al., “Regulating the Coordination Environment of MOF-Templated Single-Atom Nickel Electrocatalysts for Boosting CO₂ Reduction,” Angewandte Chemie 132, no. 7 (2020): 2727-2731.

[23] C. F. Wen, M. Zhou, P. F. Liu, et al., “Highly Ethylene-Selective Electrocatalytic CO₂ Reduction Enabled By Isolated Cu−S Motifs In Metal-Organic Framework Based Precatalysts,” Angewandte Chemie International Edition 61, no. 2 (2022): e202111700.

[24] D.-H. Nam, O. S. Bushuyev, J. Li, et al., “Metal-Organic Frameworks Mediate Cu Coordination for Selective CO₂ Electroreduction,” Journal of the American Chemical Society 140, no. 36 (2018): 11378-11386.

[25] N. A. Jose, J. J. Varghese, S. H. Mushrif, H. C. Zeng, and A. A. Lapkin, “Assembly of Two-Dimensional Metal Organic Framework Superstructures via Solvent-Mediated Oriented Attachment,” Journal of Physical Chemistry C 125, no. 41 (2021): 22837-22847.

[26] Y. Cheng, X. Wang, C. Jia, et al., “Ultrathin Mixed Matrix Membranes Containing Two-Dimensional Metal-Organic Framework Nanosheets for Efficient CO₂/CH₄ Separation,” Journal of Membrane Science 539 (2017): 213-223.

[27] P. Song, G. Natale, J. Wang, et al., “2D and 3D Metal-Organic Framework at the Oil/Water Interface: A Case Study of Copper Benzenedicarboxylate,” Advanced Materials Interfaces 6, no. 2 (2019): 1801139.

[28] X. Li, H. Zhou, F. Qi, et al., “Three Hidden Talents in One Framework: A Terephthalic Acid-Coordinated Cupric Metal-Organic Framework With Cascade Cysteine Oxidase- And Peroxidase-Mimicking Activities and Stimulus-Responsive Fluorescence for Cysteine Sensing,” Journal of Materials Chemistry B 6, no. 39 (2018): 6207-6211.

[29] A. K. Chaudhari, H. J. Kim, I. Han, and J. C. Tan, “Optochemically Responsive 2D Nanosheets of a 3D Metal-Organic Framework Material,” Advanced Materials 29, no. 27 (2017): 1701463.

[30] B. Santara, P. K. Giri, K. Imakita, and M. Fujii, “Microscopic Origin of Lattice Contraction and Expansion in Undoped Rutile TiO₂ Nanostructures,” Journal of Physics D: Applied Physics 47, no. 21 (2014): 215302.

[31] X. Zhou, J. Dong, Y. Zhu, et al., “Molecular Scalpel to Chemically Cleave Metal-Organic Frameworks for Induced Phase Transition,” Journal of the American Chemical Society 143, no. 17 (2021): 6681-6690.

[32] F. Zhang, J. Zhang, B. Zhang, et al., “CO₂ Controls the Oriented Growth of Metal-Organic Framework With Highly Accessible Active Sites,” Nature Communications 11, no. 1 (2020): 1431.

[33] T. Rodenas, I. Luz, G. Prieto, et al., “Metal-Organic Framework Nanosheets in Polymer Composite Materials for Gas Separation,” Nature Materials 14, no. 1 (2015): 48-55.

[34] M. C. Biesinger, “Advanced Analysis of Copper X-Ray Photoelectron Spectra,” Surface and Interface Analysis 49, no. 13 (2017): 1325-1334.

[35] S. Asano, K. Suzuki, D. Matsumura, et al., “Reduction and Oxidation Annealing Effects on Cu K-Edge XAFS for Electron-Doped Cuprate Superconductors,” Journal of Physics: Conference Series 2018): 12051.

[36] P. N. Floriano, L. Noble, J. M. Schoonmaker, E. D. Poliakoff, and R. L. McCarley, “Cu(0) Nanoclusters Derived From Poly(Propylene Imine) Dendrimer Complexes of Cu(II),” Journal of the American Chemical Society 123, no. 43 (2001): 10545-10553.

[37] H. Yamashita, M. Matsuoka, K. Tsuji, Y. Shioya, M. Anpo, and M. Che, “In-Situ Xafs, Photoluminescence, and IR Investigations of Copper Ions Included Within Various Kinds of Zeolites. Structure of Cu(I) Ions and Their Interaction With CO Molecules,” Journal of Physical Chemistry 100, no. 1 (1996): 397-402.

[38] A. Verdaguer-Casadevall, C. W. Li, T. P. Johansson, et al., “Probing the Active Surface Sites for CO Reduction on Oxide-Derived Copper Electrocatalysts,” Journal of the American Chemical Society 137, no. 31 (2015): 9808-9811.

[39] X. Feng, K. Jiang, S. Fan, and M. W. Kanan, “A Direct Grain-Boundary-Activity Correlation for CO Electroreduction on Cu Nanoparticles,” ACS Central Science 2, no. 3 (2016): 169-174.

[40] L. S. Kau, D. J. Spira-Solomon, J. E. Penner-Hahn, K. O. Hodgson, and E. I. Solomon, “X-ray Absorption Edge Determination of the Oxidation State and Coordination Number of Copper. Application to the Type 3 Site in Rhus Vernicifera Laccase and Its Reaction With Oxygen,” Journal of the American Chemical Society 109, no. 21 (1987): 6433-6442.

[41] C. Huang, J. Dong, W. Sun, et al., “Coordination Mode Engineering In Stacked-Nanosheet Metal-Organic Frameworks to Enhance Catalytic Reactivity and Structural Robustness,” Nature Communications 10, no. 1 (2019): 2779.

[42] X. Ma, J. Tian, M. Wang, X. Jin, M. Shen, and L. Zhang, “Metal-Organic Framework Derived Carbon Supported Cu-In Nanoparticles for Highly Selective CO₂ Electroreduction to CO,” Catalysis Science & Technology 11, no. 18 (2021): 6096-6102.

[43] W. J. Teh, M. J. Kolb, F. Calle-Vallejo, and B. S. Yeo, “Enhanced Charge Transfer Kinetics for the Electroreduction of Carbon Dioxide on Silver Electrodes Functionalized With Cationic Surfactants,” Advanced Functional Materials 33, no. 7 (2023): 2210617.

[44] Y. Lum, B. Yue, P. Lobaccaro, A. T. Bell, and J. W. Ager, “Optimizing C-C Coupling on Oxide-Derived Copper Catalysts for Electrochemical CO₂ Reduction,” Journal of Physical Chemistry C 121, no. 26 (2017): 14191-14203.

[45] T. Wu, H. Bu, S. Tao, and M. Ma, “Determination of Local pH in CO₂ Electroreduction,” Nanoscale 16, no. 8 (2024): 3926-3935.

[46] O. Ayemoba and A. Cuesta, “Spectroscopic Evidence of Size-Dependent Buffering of Interfacial pH by Cation Hydrolysis During CO₂ Electroreduction,” ACS Applied Materials & Interfaces 9, no. 33 (2017): 27377-27382.

[47] A. S. Malkani, J. Anibal, and B. Xu, “Cation Effect on Interfacial CO₂ Concentration in the Electrochemical CO₂ Reduction Reaction,” ACS Catalysis 10, no. 24 (2020): 14871-14876.

[48] N. Sikdar, J. R. C. Junqueira, S. Dieckhöfer, et al., “A Metal-Organic Framework Derived Cu_xO_yC_z Catalyst for Electrochemical CO₂ Reduction and Impact of Local pH Change,” Angewandte Chemie International Edition 60, no. 43 (2021): 23427-23434.

[49] J. Chen, H. Qiu, Y. Zhao, et al., “Selective and Stable CO₂ Electroreduction At High Rates Via Control of Local H₂O/CO₂ Ratio,” Nature Communications 15, no. 1 (2024): 5893.

[50] L. Wang, X. Yao, H. Fruehwald, et al., “Revealing Real Active Sites in Intricate Grain Boundaries Assemblies on Electroreduction of CO₂ to C₂₊ Products,” Advanced Energy Materials 15, no. 1 (2025): 2402636.

[51] T. Zhang, B. Yuan, W. Wang, J. He, and X. Xiang, “Tailoring* H Intermediate Coverage on the CuAl₂O₄/CuO Catalyst for Enhanced Electrocatalytic CO₂ Reduction to Ethanol,” Angewandte Chemie 135, no. 19 (2023): e202302096.

[52] S. Zhu, B. Jiang, W.-B. Cai, and M. Shao, “Direct Observation on Reaction Intermediates and the Role of Bicarbonate Anions in CO₂ Electrochemical Reduction Reaction on Cu Surfaces,” Journal of the American Chemical Society 139, no. 44 (2017): 15664-15667.

[53] Y. Hori, O. Koga, H. Yamazaki, and T. Matsuo, “Infrared Spectroscopy of Adsorbed CO and Intermediate Species in Electrochemical Reduction of CO₂ to Hydrocarbons on a Cu Electrode,” Electrochimica Acta 40, no. 16 (1995): 2617-2622.

[54] D. Raciti, M. Mao, J. H. Park, and C. Wang, “Local pH Effect in the CO₂ Reduction Reaction on High-Surface-Area Copper Electrocatalysts,” Journal of the Electrochemical Society 165, no. 10 (2018): F799.

[55] Y. Wang, J. Zhang, J. Zhao, et al., “Strong Hydrogen-Bonded Interfacial Water Inhibiting Hydrogen Evolution Kinetics to Promote Electrochemical CO₂ Reduction to C₂₊,” ACS Catalysis 14, no. 5 (2024): 3457-3465.

[56] C. Liu, J. Gong, J. Li, et al., “Preanodized Cu Surface for Selective CO₂ Electroreduction to C₁ or C₂₊ Products,” ACS Applied Materials & Interfaces 14, no. 18 (2022): 20953-20961.

[57] X. Yang, J. Cheng, X. Yang, Y. Xu, W. Sun, and J. Zhou, “MOF-Derived Cu@Cu₂O Heterogeneous Electrocatalyst With Moderate Intermediates Adsorption for Highly Selective Reduction of CO₂ to Methanol,” Chemical Engineering Journal 431 (2022): 134171.

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