A review on electrocatalytic CO₂ conversion via C–C and C–N coupling

Abstract

Electrochemical C–C and C–N coupling reactions with the conversion of abundant and inexpensive small molecules, such as CO₂ and nitrogen-containing species, are considered a promising route for increasing the value of CO₂ reduction products. The development of high-performance catalysts is the key to the both electrocatalytic reactions. In this review, we present a systematic summary of the reaction systems for electrocatalytic CO₂ reduction, along with the coupling mechanisms of C–C and C–N bonds over outstanding electrocatalytic materials recently developed. The key intermediate species and reaction pathways related to the coupling as well as the catalyst-structure relationship will be also discussed, aiming to provide insights and guidance for designing efficient CO₂ reduction systems.

Keywords

C–C coupling / C–N coupling / CO₂ conversion / electrocatalysis / urea synthesis

References

[1] Liu S, Wang M, Cheng Q, et al. Turning waste into wealth: sustainable production of high-value-added chemicals from catalytic coupling of carbon dioxide and nitrogenous small molecules. ACS Nano. 2022; 16 (11): 17911- 17930.

[2] Jiang M, Zhu M, Wang M, et al. Review on electrocatalytic coreduction of carbon dioxide and nitrogenous species for urea synthesis. ACS Nano. 2023; 17 (4): 3209- 3224.

[3] Peng X, Zeng L, Wang D, et al. Electrochemical C-N coupling of CO₂ and nitrogenous small molecules for the electrosynthesis of organonitrogen compounds. Chem Soc Rev. 2023; 52 (6): 2193- 2237.

[4] Li R, Xiang K, Liu Z, Peng Z, Zou Y, Wang S. Recent advances in upgrading of low-cost oxidants to value-added products by electrocatalytic reduction reaction. Adv Funct Mater. 2022; 32 (46): 2208212.

[5] Li L, Li X, Sun Y, Xie Y. Rational design of electrocatalytic carbon dioxide reduction for a zero-carbon network. Chem Soc Rev. 2022; 51 (4): 1234- 1252.

[6] Ma X, Zhang Y, Fan T, et al. Facet dopant regulation of Cu₂O boosts electrocatalytic CO₂ reduction to formate. Adv Funct Mater. 2023; 33 (16): 2213145.

[7] Jiao Y, Zheng Y, Chen P, Jaroniec M, Qiao S-Z. Molecular scaffolding strategy with synergistic active centers to facilitate electrocatalytic CO₂ reduction to hydrocarbon/alcohol. J Am Chem Soc. 2017; 139 (49): 18093- 18100.

[8] Li L, Huang Y, Li Y. Carbonaceous materials for electrochemical CO₂ reduction. Energy Chem. 2020; 2 (1): 100024.

[9] Wang ZL, Choi J, Xu M, et al. Optimizing electron densities of Ni-N-C complexes by hybrid coordination for efficient electrocatalytic CO₂ reduction. ChemSusChem. 2020; 13 (5): 929- 937.

[10] Ding X, Zhang J, Li Y. CO electroreduction: what can we learn from its parent reaction, CO₂ electroreduction? eScience. 2023; 3 (6): 100137.

[11] Zhang J, Pan B, Li Y. Modulating electrochemical CO₂ reduction at interfaces. Sci Bull. 2022; 67 (18): 1844- 1848.

[12] Zhang J, Mao X, Pan B, et al. Surface promotion of copper nanoparticles with alumina clusters derived from layered double hydroxide accelerates CO₂ reduction to ethylene in membrane electrode assemblies. Nano Res. 2022; 16 (4): 4685- 4690.

[13] Fang M, Wang M, Wang Z, et al. Hydrophobic, ultrastable Cu^δ+ for robust CO₂ electroreduction to C₂ products at ampere-current levels. J Am Chem Soc. 2023; 145 (20): 11323- 11332.

[14] Wang G, Chen J, Ding Y, et al. Electrocatalysis for CO₂ conversion: from fundamentals to value-added products. Chem Soc Rev. 2021; 50 (8): 4993- 5061.

[15] Zhang W, Jin Z, Chen Z. Rational-designed principles for electrochemical and photoelectrochemical upgrading of CO₂ to value-added chemicals. Adv Sci. 2022; 9 (9): 2105204.

[16] Harmon NJ, Wang H. Electrochemical CO₂ reduction in the presence of impurities: influences and mitigation strategies. Angew Chem Int Ed. 2022; 61 (52): e202213782.

[17] Feng J, Wu L, Liu S, et al. Improving CO₂-to-C₂₊ product electroreduction efficiency via atomic lanthanide dopant-induced tensile-strained CuO_x catalysts. J Am Chem Soc. 2023; 145 (17): 9857- 9866.

[18] Li J, Zhang Y, Kuruvinashetti K, Kornienko N. Construction of C-N bonds from small-molecule precursors through heterogeneous electrocatalysis. Nat Rev Chem. 2022; 6 (5): 303- 319.

[19] Wang D, Chen C, Wang S. Defect engineering for advanced electrocatalytic conversion of nitrogen-containing molecules. Sci China Chem. 2022; 66 (4): 1052- 1072.

[20] Li JY, Song QW, Zhang K, Liu P. Catalytic conversion of carbon dioxide through C-N bond formation. Molecules. 2019; 24 (1): 182.

[21] Seger B, Robert M, Jiao F. Best practices for electrochemical reduction of carbon dioxide. Nat Sustain. 2023; 6 (3): 236- 238.

[22] Ma S, Sadakiyo M, Luo R, Heima M, Yamauchi M, Kenis PJA. One-step electrosynthesis of ethylene and ethanol from CO₂ in an alkaline electrolyzer. J Power Sources. 2016; 301: 219- 228.

[23] Zhang Z, Huang X, Chen Z, et al. Membrane electrode assembly for electrocatalytic CO₂ reduction: principle and application. Angew Chem Int Ed. 2023; 62 (28): e202302789.

[24] Yan C, Li H, Ye Y, et al. Coordinatively unsaturated nickel-nitrogen sites towards selective and high-rate CO₂ electroreduction. Energy Environ Sci. 2018; 11 (5): 1204- 1210.

[25] Ma W, Xie S, Zhang X-G, et al. Promoting electrocatalytic CO₂ reduction to formate via sulfur-boosting water activation on indium surfaces. Nat Commun. 2019; 10 (1): 892.

[26] Rangraz Y, Heravi MM. Recent advances in the application of nanocatalysts in C-N coupling reactions. Appl Organomet Chem. 2022; 37 (1): e681.

[27] Li J, Kuang Y, Meng Y, et al. Electroreduction of CO₂ to formate on a copper-based electrocatalyst at high pressures with high energy conversion efficiency. J Am Chem Soc. 2020; 142 (16): 7276- 7282.

[28] Hou J, Chang X, Li J, Xu B, Lu Q. Correlating CO coverage and CO electroreduction on Cu via high-pressure in situ spectroscopic and reactivity investigations. J Am Chem Soc. 2022; 144 (48): 22202- 22211.

[29] Luo Y, Zhang K, Li Y, Wang Y. Valorizing carbon dioxide via electrochemical reduction on gas-diffusion electrodes. InfoMat. 2021; 3 (12): 1313- 1332.

[30] Li H, Liu T, Wei P, et al. High-rate CO₂ electroreduction to C₂₊ products over a copper-copper iodide catalyst. Angew Chem Int Ed. 2021; 60 (26): 14329- 14333.

[31] Xie M, Shen Y, Ma W, et al. Fast screening for copper-based bimetallic electrocatalysts: efficient electrocatalytic reduction of CO₂ to C₂₊ products on magnesium-modified copper. Angew Chem Int Ed. 2022; 61 (51): e202213423.

[32] Peng C, Luo G, Xu Z, et al. Lithiation-enabled high-density nitrogen vacancies electrocatalyze CO₂ to C₂ products. Adv Mater. 2021; 33 (40): 2103150.

[33] Zheng M, Wang P, Zhi X, et al. Electrocatalytic CO₂-to-C₂₊ with ampere-level current on heteroatom-engineered copper via tuning *CO intermediate coverage. J Am Chem Soc. 2022; 144 (32): 14936- 14944.

[34] Xu A, Hung S-F, Cao A, et al. Copper/alkaline earth metal oxide interfaces for electrochemical CO₂-to-alcohol conversion by selective hydrogenation. Nat Catal. 2022; 5 (12): 1081- 1088.

[35] García de Arquer FP, Dinh C-T, Ozden A, et al. CO₂ electrolysis to multicarbon products at activities greater than 1 A cm⁻². Science. 2020; 367 (6478): 661- 666.

[36] Huang JE, Li F, Ozden A, et al. CO₂ electrolysis to multicarbon products in strong acid. Science. 2021; 372 (6546): 1074- 1078.

[37] Whipple DT, Finke EC, Kenis PJA. Microfluidic reactor for the electrochemical reduction of carbon dioxide: the effect of pH. Electrochem Solid State Lett. 2010; 13 (9): B109- B111.

[38] Thorson MR, Siil KI, Kenis PJA. Effect of cations on the electrochemical conversion of CO₂ to CO. J Electrochem Soc. 2012; 160 (1): F69- F74.

[39] Pan B, Wang Y, Li Y. Understanding and leveraging the effect of cations in the electrical double layer for electrochemical CO₂ reduction. Chem Catal. 2022; 2 (6): 1267- 1276.

[40] Kormányos A, Endrődi B, Zhang Z, et al. Local hydrophobicity allows high-performance electrochemical carbon monoxide reduction to C₂₊ products. EES Catal. 2023; 1 (3): 263- 273.

[41] Zhang J, Luo W, Züttel A. Crossover of liquid products from electrochemical CO₂ reduction through gas diffusion electrode and anion exchange membrane. J Catal. 2020; 385: 140- 145.

[42] Niu Z-Z, Chi L-P, Liu R, Chen Z, Gao M-R. Rigorous assessment of CO₂ electroreduction products in a flow cell. Energy Environ Sci. 2021; 14 (8): 4169- 4176.

[43] Chen C, Khosrowabadi Kotyk JF, Sheehan SW. Progress toward commercial application of electrochemical carbon dioxide reduction. Chem. 2018; 4 (11): 2571- 2586.

[44] Burdyny T, Smith WA. CO₂ reduction on gas-diffusion electrodes and why catalytic performance must be assessed at commercially-relevant conditions. Energy Environ Sci. 2019; 12 (5): 1442- 1453.

[45] Zhang G, Li L, Zhao Z-J, Wang T, Gong J. Electrochemical approaches to CO₂ conversion on copper-based catalysts. Acc Mater Res. 2023; 4 (3): 212- 222.

[46] Ge L, Rabiee H, Li M, et al. Electrochemical CO₂ reduction in membrane-electrode assemblies. Chem. 2022; 8 (3): 663- 692.

[47] Yang Y, Li P, Zheng X, et al. Anion-exchange membrane water electrolyzers and fuel cells. Chem Soc Rev. 2022; 51 (23): 9620- 9693.

[48] Carmo M, Fritz DL, Mergel J, Stolten D. A comprehensive review on PEM water electrolysis. Int J Hydrogen Energy. 2013; 38 (12): 4901- 4934.

[49] Endrődi B, Kecsenovity E, Samu A, et al. High carbonate ion conductance of a robust PiperION membrane allows industrial current density and conversion in a zero-gap carbon dioxide electrolyzer cell. Energy Environ Sci. 2020; 13 (11): 4098- 4105.

[50] Endrődi B, Kecsenovity E, Samu A, et al. Multilayer electrolyzer stack converts carbon dioxide to gas products at high pressure with high efficiency. ACS Energy Lett. 2019; 4 (7): 1770- 1777.

[51] Wei P, Gao D, Liu T, et al. Coverage-driven selectivity switch from ethylene to acetate in high-rate CO₂/CO electrolysis. Nat Nanotechnol. 2023; 18 (3): 299- 306.

[52] Ozden A, García de Arquer FP, Huang JE, et al. Carbon-efficient carbon dioxide electrolysers. Nat Sustain. 2022; 5 (7): 563- 573.

[53] Salvatore DA, Gabardo CM, Reyes A, et al. Designing anion exchange membranes for CO₂ electrolysers. Nat Energy. 2021; 6 (4): 339- 348.

[54] McCallum C, Gabardo CM, O'Brien CP, et al. Reducing the crossover of carbonate and liquid products during carbon dioxide electroreduction. Cell Rep Phys Sci. 2021; 2 (8): 100522.

[55] Sassenburg M, Kelly M, Subramanian S, Smith WA, Burdyny T. Zero-gap electrochemical CO₂ reduction cells: challenges and operational strategies for prevention of salt precipitation. ACS Energy Lett. 2023; 8 (1): 321- 331.

[56] Hasa B, Cherniack L, Xia R, et al. Benchmarking anion-exchange membranes for electrocatalytic carbon monoxide reduction. Chem Catal. 2023; 3 (1): 100450.

[57] O'Brien CP, Miao RK, Liu S, et al. Single pass CO₂ conversion exceeding 85% in the electrosynthesis of multicarbon products via local CO₂ regeneration. ACS Energy Lett. 2021; 6 (8): 2952- 2959.

[58] Yang K, Li M, Subramanian S, Blommaert MA, Smith WA, Burdyny T. Cation-driven increases of CO₂ utilization in a bipolar membrane electrode assembly for CO₂ electrolysis. ACS Energy Lett. 2021; 6 (12): 4291- 4298.

[59] Blommaert MA, Aili D, Tufa RA, Li Q, Smith WA, Vermaas DA. Insights and challenges for applying bipolar membranes in advanced electrochemical energy systems. ACS Energy Lett. 2021; 6 (7): 2539- 2548.

[60] Zhu P, Wang H. High-purity and high-concentration liquid fuels through CO₂ electroreduction. Nat Catal. 2021; 4 (11): 943- 951.

[61] Xia C, Zhu P, Jiang Q, et al. Continuous production of pure liquid fuel solutions via electrocatalytic CO₂ reduction using solid-electrolyte devices. Nat Energy. 2019; 4 (9): 776- 785.

[62] Fan L, Xia C, Zhu P, Lu Y, Wang H. Electrochemical CO₂ reduction to high-concentration pure formic acid solutions in an all-solid-state reactor. Nat Commun. 2020; 11 (1): 3633.

[63] Miao RK, Xu Y, Ozden A, et al. Electroosmotic flow steers neutral products and enables concentrated ethanol electroproduction from CO₂. Joule. 2021; 5 (10): 2742- 2753.

[64] Zheng T, Liu C, Guo C, et al. Copper-catalysed exclusive CO₂ to pure formic acid conversion via single-atom alloying. Nat Nanotechnol. 2021; 16 (12): 1386- 1393.

[65] Kim JYT, Zhu P, Chen F-Y, Wu ZY, Cullen DA, Wang H. Recovering carbon losses in CO₂ electrolysis using a solid electrolyte reactor. Nat Catal. 2022; 5 (4): 288- 299.

[66] Xu Y, Miao RK, Edwards JP, et al. A microchanneled solid electrolyte for carbon-efficient CO₂ electrolysis. Joule. 2022; 6 (6): 1333- 1343.

[67] Todorova TK, Schreiber MW, Fontecave M. Mechanistic understanding of CO₂ reduction reaction CO₂RR toward multicarbon products by heterogeneous copper-based catalysts. ACS Catal. 2019; 10 (3): 1754- 1768.

[68] Fan L, Xia C, Yang F, Wang J, Wang H, Lu Y. Strategies in catalysts and electrolyzer design for electrochemical CO₂ reduction toward C₂₊ products. Sci Adv. 2020; 6 (8): eaay3111.

[69] Ma W, He X, Wang W, Xie S, Zhang Q, Wang Y. Electrocatalytic reduction of CO₂ and CO to multi-carbon compounds over Cu-based catalysts. Chem Soc Rev. 2021; 50 (23): 12897- 12914.

[70] Nguyen TN, Guo J, Sachindran A, Li F, Seifitokaldani A, Dinh CT. Electrochemical CO₂ reduction to ethanol: from mechanistic understanding to catalyst design. J Mater Chem A. 2021; 9 (21): 12474- 12494.

[71] Wang Y, Liu J, Zheng G. Designing copper-based catalysts for efficient carbon dioxide electroreduction. Adv Mater. 2021; 33 (46): e2005798.

[72] Shi Y, Hou M, Li J, Li L, Zhang Z. Cu-based tandem catalysts for electrochemical CO₂ reduction. Acta Phys Chim Sin. 2022; 38 (11): 2206020.

[73] Liu LX, Cai Y, Du H, et al. Enriching the local concentration of CO intermediates on Cu cavities for the electrocatalytic reduction of CO₂ to C₂₊ products. ACS Appl Mater Interfaces. 2023; 15 (13): 16673- 16679.

[74] Yang Y, Louisia S, Yu S, et al. Operando studies reveal active Cu nanograins for CO₂ electroreduction. Nature. 2023; 614 (7947): 262- 269.

[75] Tan YC, Lee KB, Song H, Oh J. Modulating local CO₂ concentration as a general strategy for enhancing C-C coupling in CO₂ electroreduction. Joule. 2020; 4 (5): 1104- 1120.

[76] Yoshio H, Katsuhei K, Akira M, Suzuki S. Production of methane and ethylene in electrochemical reduction of carbon dioxide at copper electrode in aqueous hydrogencarbonate solution. Chem Lett. 1986; 15 (6): 897- 898.

[77] Zhao K, Quan X. Carbon-based materials for electrochemical reduction of CO₂ to C₂₊ oxygenates: recent progress and remaining challenges. ACS Catal. 2021; 11 (4): 2076- 2097.

[78] Li L, Su J, Lu J, Shao Q. Recent advances of core-shell Cu-based catalysts for the reduction of CO₂ to C₂₊ products. Chem Asian J. 2023; 18 (5): e202201044.

[79] Xiang K, Shen F, Fu Y, et al. Boosting CO₂ electroreduction towards C₂₊ products via CO* intermediate manipulation on copper-based catalysts. Environ Sci Nano. 2022; 9 (3): 911- 953.

[80] Wang H, Matios E, Wang C, et al. Rapid and scalable synthesis of cuprous halide-derived copper nano-architectures for selective electrochemical reduction of carbon dioxide. Nano Lett. 2019; 19 (6): 3925- 3932.

[81] Yang Y, Tan Z, Wang S, et al. Cu/Cu₂O nanocrystals for electrocatalytic carbon dioxide reduction to multi-carbon products. Chem Commun. 2023; 59 (17): 2445- 2448.

[82] Song P, Zhu P, Su X, Hou M, Zhao D, Zhang J. Microenvironment modulation in carbon-supported single-atom catalysts for efficient electrocatalytic CO₂ reduction. Chem Asian J. 2022; 17 (20): e202200716.

[83] Xie H, Xie R, Zhang Z, et al. Achieving highly selective electrochemical CO₂ reduction to C₂H₄ on Cu nanosheets. J Energy Chem. 2023; 79: 312- 320.

[84] Fu Y, Xie Q, Wan L, Huang Q, Luo J. Ethanol assisted cyclic voltammetry treatment of copper for electrochemical CO₂ reduction to ethylene. Mater Today Energy. 2022; 29: 101105.

[85] Jiang K, Sandberg RB, Akey AJ, et al. Metal ion cycling of Cu foil for selective C-C coupling in electrochemical CO₂ reduction. Nat Catal. 2018; 1 (2): 111- 119.

[86] Zhong D, Zhao ZJ, Zhao Q, et al. Coupling of Cu(100) and (110) facets promotes carbon dioxide conversion to hydrocarbons and alcohols. Angew Chem Int Ed. 2021; 60 (9): 4879- 4885.

[87] Ma W, Xie S, Liu T, et al. Electrocatalytic reduction of CO₂ to ethylene and ethanol through hydrogen-assisted C-C coupling over fluorine-modified copper. Nat Catal. 2020; 3 (6): 478- 487.

[88] Hu F, Yang L, Jiang Y, et al. Ultrastable Cu catalyst for CO₂ electroreduction to multicarbon liquid fuels by tuning C-C coupling with CuTi subsurface. Angew Chem Int Ed. 2021; 60 (50): 26122- 26127.

[89] Gao J, Bahmanpour A, Kröcher O, Zakeeruddin SM, Ren D, Grätzel M. Electrochemical synthesis of propylene from carbon dioxide on copper nanocrystals. Nat Chem. 2023; 15 (5): 705- 713.

[90] Qi K, Zhang Y, Onofrio N, et al. Unlocking direct CO₂ electrolysis to C₃ products via electrolyte supersaturation. Nat Catal. 2023; 6 (4): 319- 331.

[91] Farooqi SA, Farooqi AS, Sajjad S, Yan C, Victor AB. Electrochemical reduction of carbon dioxide into valuable chemicals: a review. Environ Chem Lett. 2023; 21 (3): 1515- 1553.

[92] Kanase RS, Lee KB, Arunachalam M, Sivasankaran RP, Oh J, Kang SH. Nanostructure engineering of Cu electrocatalyst for the selective C₂₊ hydrocarbons in electrochemical CO₂ reduction. Appl Surf Sci. 2022; 584: 152518.

[93] Chang F, Wei J, Liu Y, Wang W, Yang L, Bai Z. Surface/interface reconstruction in-situ on Cu₂O catalysts with high exponential facets toward enhanced electrocatalysis CO₂ reduction to C₂₊ products. Appl Surf Sci. 2023; 611: 155773.

[94] Fu Y, Xie Q, Wu L, Luo J. Crystal facet effect induced by different pretreatment of Cu₂O nanowire electrode for enhanced electrochemical CO₂ reduction to C₂₊ products. Chin J Catal. 2022; 43 (4): 1066- 1073.

[95] Ye W, Guo X, Ma T. A review on electrochemical synthesized copper-based catalysts for electrochemical reduction of CO₂ to C₂₊ products. Chem Eng J. 2021; 414: 128825.

[96] Ye M, Shao T, Liu J, Li C, Song B, Liu S. Phase engineering of Cu@Cu₂O core-shell nanospheres for boosting tandem electrochemical CO₂ reduction to C₂₊ products. Appl Surf Sci. 2023; 622: 156981.

[97] Wang X, Jiang Y, Mao K, et al. Identifying an interfacial stabilizer for regeneration-free 300 h electrochemical CO₂ reduction to C₂ products. J Am Chem Soc. 2022; 144 (49): 22759- 22766.

[98] Pan F, Yang X, O'Carroll T, Li H, Chen KJ, Wu G. Carbon catalysts for electrochemical CO₂ reduction toward multicarbon products. Adv Energy Mater. 2022; 12 (24): 2200586.

[99] Zhao K, Liu Y, Quan X, Chen S, Yu H. CO₂ electroreduction at low overpotential on oxide-derived Cu/carbons fabricated from metal organic framework. ACS Appl Mater Interfaces. 2017; 9 (6): 5302- 5311.

[100] Zhao Y, Zheng L, Jiang D, et al. Nanoengineering metal-organic framework-based materials for use in electrochemical CO₂ reduction reactions. Small. 2021; 17 (16): 2006590.

[101] Zhang L, Merino-Garcia I, Albo J, Sánchez-Sánchez CM. Electrochemical CO₂ reduction reaction on cost-effective oxide-derived copper and transition metal-nitrogen-carbon catalysts. Curr Opin Electrochem. 2020; 23: 65- 73.

[102] Zhu C, Fu S, Shi Q, Du D, Lin Y. Single-atom electrocatalysts. Angew Chem Int Ed. 2017; 56 (45): 13944- 13960.

[103] Chen Y, Ji S, Chen C, Peng Q, Wang D, Li Y. Single-atom catalysts: synthetic strategies and electrochemical applications. Joule. 2018; 2 (7): 1242- 1264.

[104] Zhang Z, Xiao J, Chen XJ, et al. Reaction mechanisms of well-defined metal-N₄ sites in electrocatalytic CO₂ reduction. Angew Chem Int Ed. 2018; 57 (50): 16339- 16342.

[105] Zhang Z, Ma C, Tu Y, et al. Multiscale carbon foam confining single iron atoms for efficient electrocatalytic CO₂ reduction to CO. Nano Res. 2019; 12 (9): 2313- 2317.

[106] Wang Y, Mao J, Meng X, Yu L, Deng D, Bao X. Catalysis with two-dimensional materials confining single atoms: concept, design, and applications. Chem Rev. 2018; 119 (3): 1806- 1854.

[107] Karapinar D, Huan NT, Ranjbar Sahraie N, et al. Electroreduction of CO₂ on single-site copper-nitrogen-doped carbon material: selective formation of ethanol and reversible restructuration of the metal sites. Angew Chem Int Ed. 2019; 58 (42): 15098- 15103.

[108] Jiao J, Lin R, Liu S, et al. Copper atom-pair catalyst anchored on alloy nanowires for selective and efficient electrochemical reduction of CO₂. Nat Chem. 2019; 11 (3): 222- 228.

[109] Xie H, Wang F, Liu T, et al. Copper-iron dimer for selective C-C coupling in electrochemical CO₂ reduction. Electrochim Acta. 2021; 380: 138188.

[110] Nitopi S, Bertheussen E, Scott SB, et al. Progress and perspectives of electrochemical CO₂ reduction on copper in aqueous electrolyte. Chem Rev. 2019; 119 (12): 7610- 7672.

[111] Centi G, Perathoner S, Winè G, Gangeri M. Electrocatalytic conversion of CO₂ to long carbon-chain hydrocarbons. Green Chem. 2007; 9 (6): 671- 678.

[112] Cui Y, Yang C, Lin H, et al. Amorphous N_xC coating promotes electrochemical CO₂ deep reduction to hydrocarbons over Ag nanocatalysts. ACS Catal. 2023; 13 (1): 169- 178.

[113] Qin J, Wang T, Zhai M, et al. Hydroxypillar[5] arene-confined silver nanocatalyst for selective electrochemical reduction of CO₂ to ethanol. Adv Funct Mater. 2023; 33 (29): 2300697.

[114] Chen P, Zhang P, Kang X, et al. Efficient electrocatalytic reduction of CO₂ to ethane over nitrogen-doped Fe₂O₃. J Am Chem Soc. 2022; 144 (32): 14769- 14777.

[115] Calvinho KUD, Laursen AB, Yap KMK, et al. Selective CO₂ reduction to C₃ and C₄ oxyhydrocarbons on nickel phosphides at overpotentials as low as 10 mV. Energy Environ Sci. 2018; 11 (9): 2550- 2559.

[116] Cronin SP, Dulovic S, Lawrence JA, et al. Direct synthesis of 1-butanol with high Faradaic efficiency from CO₂ utilizing cascade catalysis at a Ni-enhanced (Cr₂O₃)₃Ga₂O₃ electrocatalyst. J Am Chem Soc. 2023; 145 (12): 6762- 6772.

[117] Du J, Cheng B, Yuan H, et al. Molecular nickel thiolate complexes for electrochemical reduction of CO₂ to C_1-3 hydrocarbons. Angew Chem Int Ed. 2023; 62 (9): e202211804.

[118] Zhou Y, Martín AJ, Dattila F, et al. Long-chain hydrocarbons by CO₂ electroreduction using polarized nickel catalysts. Nat Catal. 2022; 5 (6): 545- 554.

[119] Paris AR, Bocarsly AB. Ni-Al films on glassy carbon electrodes generate an array of oxygenated organics from CO₂. ACS Catal. 2017; 7 (10): 6815- 6820.

[120] Kim C, Jeon HS, Eom T, et al. Achieving selective and efficient electrocatalytic activity for CO₂ reduction using immobilized silver nanoparticles. J Am Chem Soc. 2015; 137 (43): 13844- 13850.

[121] Liu S, Tao H, Zeng L, et al. Shape-dependent electrocatalytic reduction of CO₂ to CO on triangular silver nanoplates. J Am Chem Soc. 2017; 139 (6): 2160- 2163.

[122] Endrődi B, Samu A, Kecsenovity E, Halmágyi T, Sebők D, Janáky C. Operando cathode activation with alkali metal cations for high current density operation of water-fed zero-gap carbon dioxide electrolysers. Nat Energy. 2021; 6 (4): 439- 448.

[123] Samu AA, Kormányos A, Kecsenovity E, Szilágyi N, Endrődi B, Janáky C. Intermittent operation of CO₂ electrolyzers at industrially relevant current densities. ACS Energy Lett. 2022; 7 (5): 1859- 1861.

[124] Du J, Li S, Liu S, et al. Selective electrochemical reduction of carbon dioxide to ethanol via a relay catalytic platform. Chem Sci. 2020; 11 (19): 5098- 5104.

[125] Ait Ahsaine H, Zbair M, BaQais A, Arab M. CO₂ electroreduction over metallic oxide, carbon-based, and molecular catalysts: a mini-review of the current advances. Catalysts. 2022; 12 (5): 450.

[126] Xue D, Xia H, Yan W, Zhang J, Mu S. Defect engineering on carbon-based catalysts for electrocatalytic CO₂ reduction. Nano Lett. 2020; 13 (1): 5.

[127] Zhang Z, Yu L, Tu Y, et al. Unveiling the active site of metal-free nitrogen-doped carbon for electrocatalytic carbon dioxide reduction. Cell Rep Phys Sci. 2020; 1 (8): 100145.

[128] Wu J, Ma S, Sun J, et al. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates. Nat Commun. 2016; 7 (1): 13869.

[129] Yang F, Ma X, Cai WB, Song P, Xu W. Nature of oxygen-containing groups on carbon for high-efficiency electrocatalytic CO₂ reduction reaction. J Am Chem Soc. 2019; 141 (51): 20451- 20459.

[130] Masood ul Hasan I, Peng L, Mao J, et al. Carbon-based metal-free catalysts for electrochemical CO₂ reduction: activity, selectivity, and stability. Carbon Energy. 2020; 3 (1): 24- 49.

[131] Mao X, Guo R, Chen Q, et al. Recent advances in graphitic carbon nitride based electro-catalysts for CO₂ reduction reactions. Molecules. 2023; 28 (8): 3292.

[132] Feng Y, Yang H, Zhang Y, et al. Te-doped Pd nanocrystal for electrochemical urea production by efficiently coupling carbon dioxide reduction with nitrite reduction. Nano Lett. 2020; 20 (11): 8282- 8289.

[133] Meng N, Huang Y, Liu Y, Yu Y, Zhang B. Electrosynthesis of urea from nitrite and CO₂ over oxygen vacancy-rich ZnO porous nanosheets. Cell Rep Phys Sci. 2021; 2 (3): 100378.

[134] Liu S, Yin S, Wang Z, et al. AuCu nanofibers for electrosynthesis of urea from carbon dioxide and nitrite. Cell Rep Phys Sci. 2022; 3 (5): 100869.

[135] Cao N, Quan Y, Guan A, et al. Oxygen vacancies enhanced cooperative electrocatalytic reduction of carbon dioxide and nitrite ions to urea. J Colloid Interface Sci. 2020; 577: 109- 114.

[136] Shibata M, Furuya N. Electrochemical synthesis of urea at gas-diffusion electrodes. J Electroanal Chem. 2001; 507 (1-2): 177- 184.

[137] Saravanakumar D, Song J, Lee S, Hur NH, Shin W. Electrocatalytic conversion of carbon dioxide and nitrate ions to urea by a titania-nafion composite electrode. ChemSusChem. 2017; 10 (20): 3999- 4003.

[138] Lv C, Zhong L, Liu H, et al. Selective electrocatalytic synthesis of urea with nitrate and carbon dioxide. Nat Sustain. 2021; 4 (10): 868- 876.

[139] Wang H, Jiang Y, Li S, et al. Realizing efficient C-N coupling via electrochemical co-reduction of CO₂ and NO₃⁻ on AuPd nanoalloy to form urea: key C-N coupling intermediates. Appl Catal B. 2022; 318 (5): 121819.

[140] White JL, Baruch MF, Pander III JE, et al. Light-driven heterogeneous reduction of carbon dioxide: photocatalysts and photoelectrodes. Chem Rev. 2015; 115 (23): 12888- 12935.

[141] Lv C, Lee C, Zhong L, et al. A defect engineered electrocatalyst that promotes high-efficiency urea synthesis under ambient conditions. ACS Nano. 2022; 16 (5): 8213- 8222.

[142] Liu X, Kumar PV, Chen Q, et al. Carbon nanotubes with fluorine-rich surface as metal-free electrocatalyst for effective synthesis of urea from nitrate and CO₂. Appl Catal B. 2022; 316 (5): 121618.

[143] Leverett J, Tran-Phu T, Yuwono JA, et al. Tuning the coordination structure of Cu-N-C single atom catalysts for simultaneous electrochemical reduction of CO₂ and NO₃⁻ to urea. Adv Energy Mater. 2022; 12 (32): 2201500.

[144] Wei X, Wen X, Liu Y, et al. Oxygen vacancy-mediated selective C-N coupling toward electrocatalytic urea synthesis. J Am Chem Soc. 2022; 144 (26): 11530- 11535.

[145] Wei X, Liu Y, Zhu X, et al. Dynamic reconstitution between copper single atoms and clusters for electrocatalytic urea synthesis. Adv Mater. 2023; 35 (18): 2300020.

[146] Liu Y, Tu X, Wei X, et al. C-bound or O-bound surface: which one boosts electrocatalytic urea synthesis? Angew Chem Int Ed. 2023; 62 (19): e2023003.

[147] Meng N, Ma X, Wang C, et al. Oxide-derived core-shell Cu@Zn nanowires for urea electrosynthesis from carbon dioxide and nitrate in water. ACS Nano. 2022; 16 (6): 9095- 9104.

[148] Chen C, Zhu X, Wen X, et al. Coupling N₂ and CO₂ in H₂O to synthesize urea under ambient conditions. Nat Chem. 2020; 12 (8): 717- 724.

[149] Yuan M, Chen J, Zhang H, et al. Host-guest molecular interaction promoted urea electrosynthesis over a precisely designed conductive metal-organic framework. Energy Environ Sci. 2022; 15 (5): 2084- 2095.

[150] Yuan M, Chen J, Bai Y, et al. Unveiling electrochemical urea synthesis by co-activation of CO₂ and N₂ with Mott-Schottky heterostructure catalysts. Angew Chem Int Ed. 2021; 60 (19): 10910- 10918.

[151] Yuan M, Chen J, Bai Y, et al. Electrochemical C-N coupling with perovskite hybrids toward efficient urea synthesis. Chem Sci. 2021; 12 (17): 6048- 6058.

[152] Yuan M, Chen J, Xu Y, et al. Highly selective electroreduction of N₂ and CO₂ to urea over artificial frustrated Lewis pairs. Energy Environ Sci. 2021; 14 (12): 6605- 6615.

[153] Yuan M, Zhang H, Xu Y, et al. Artificial frustrated Lewis pairs facilitating the electrochemical N₂ and CO₂ conversion to urea. Chem Catal. 2022; 2 (2): 309- 320.

[154] Huang Y, Yang R, Wang C, et al. Direct electrosynthesis of urea from carbon dioxide and nitric oxide. ACS Energy Lett. 2021; 7 (1): 284- 291.

[155] Wu Y, Jiang Z, Lin Z, Liang Y, Wang H. Direct electrosynthesis of methylamine from carbon dioxide and nitrate. Nat Sustain. 2021; 4 (8): 725- 730.

[156] Tao Z, Wu Y, Wu Z, Shang B, Rooney C, Wang H. Cascade electrocatalytic reduction of carbon dioxide and nitrate to ethylamine. J Energy Chem. 2022; 65: 367- 370.

[157] Li J, Kornienko N. Electrochemically driven C-N bond formation from CO₂ and ammonia at the triple-phase boundary. Chem Sci. 2022; 13 (14): 3957- 3964.

[158] Tao Z, Rooney CL, Liang Y, Wang H. Accessing organonitrogen compounds via C-N coupling in electrocatalytic CO₂ reduction. J Am Chem Soc. 2021; 143 (47): 19630- 19642.

[159] Chen C, He N, Wang S. Electrocatalytic C-N coupling for urea synthesis. Small Sci. 2021; 1 (11): 2100070.

[160] Shibata M, Yoshida K, Furuya N. Electrochemical synthesis of urea on reduction of carbon dioxide with nitrate and nitrite ions using Cu-loaded gas-diffusion electrode. J Electroanal Chem. 1995; 387 (1-2): 143- 145.

[161] Shibata M, Yoshida K, Furuya N. Electrochemical synthesis of urea at gas-diffusion electrodes V. Simultaneous reduction of carbon dioxide and nitrite ions with various boride catalysts. Denki Kagaku Oyobi Kogyo Butsuri Kagaku. 1998; 66 (6): 584- 589.

[162] Shibata M, Yoshida K, Furuya N. Electrochemical synthesis of urea at gas-diffusion electrodes: IV. Simultaneous reduction of carbon dioxide and nitrate ions with various metal catalysts. J Electrochem Soc. 1998; 145 (7): 2348- 2353.

[163] Shibata M, Yoshida K, Furuya N. Electrochemical synthesis of urea at gas-diffusion electrodes. J Electroanal Chem. 1998; 442 (1-2): 67- 72.

[164] Filippi M, Möller T, Liang L, Strasser P. Understanding the impact of catholyte flow compartment design on the efficiency of CO₂ electrolyzers. Energy Environ Sci. 2023; 16 (11): 5265- 5273.

[165] Jiao Y, Li H, Jiao Y, Qiao S-Z. Activity and selectivity roadmap for C-N electro-coupling on MXenes. J Am Chem Soc. 2023; 145 (28): 15572- 15580.

[166] Li J, Al-Mahayni H, Chartrand D, Seifitokaldani A, Kornienko N. Electrochemical formation of C-S bonds from CO₂ and small-molecule sulfur species. Nat Synth. 2023; 2 (8): 757- 765.

RIGHTS & PERMISSIONS

2024 2024 The Authors. Carbon Energy published by Wenzhou University and John Wiley & Sons Australia, Ltd.