Realizing the Use of Molecular Electrocatalysts for Conversion of CO2 to Multielectron Products

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Read the latest articles CiteCitationCitation and abstractCitation and referencesMore citation options ShareShare onFacebookX (Twitter)WeChatLinkedInRedditEmailJump toExpandCollapse CommentAugust 30, 2024Realizing the Use of Molecular Electrocatalysts for Conversion of CO2 to Multielectron ProductsClick to copy article linkArticle link copied!Arnab Ghatak*Arnab GhatakDepartment of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel*E-mail: email protectedMore by Arnab Ghatakhttps://orcid.org/0000-0003-3027-9359Idan Hod*Idan HodDepartment of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel*E-mail: email protectedMore by Idan Hodhttps://orcid.org/0000-0003-4837-8793Open PDFArtificial PhotosynthesisCite this: Artif. Photosynth. 2024, XXXX, XXX, XXX-XXXClick to copy citationCitation copied!https://pubs.acs.org/doi/10.1021/aps.4c00011https://doi.org/10.1021/aps.4c00011Published August 30, 2024 Publication History Received 7 July 2024Accepted 6 August 2024Revised 1 August 2024Published online 30 August 2024article-commentary© 2024 The Authors. Co-published by Dalian Institute of Chemical Physics, CAS, Westlake University, and American Chemical Society. This publication is licensed under CC-BY-NC-ND 4.0 . License Summary*You are free to share (copy and redistribute) this article in any medium or format within the parameters below:Creative Commons (CC): This is a Creative Commons license.Attribution (BY): Credit must be given to the creator.Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license*DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. This publication is licensed underCC-BY-NC-ND 4.0 . License Summary*You are free to share(copy and redistribute) this article in any medium or format within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator.Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. ACS Publications© 2024 The Authors. Co-published by Dalian Institute of Chemical Physics, CAS, Westlake University, and American Chemical SocietySubjectswhat are subjectsArticle subjects are automatically applied from the ACS Subject Taxonomy and describe the scientific concepts and themes of the article.CatalystsCobaltElectrocatalystsElectrolysisRedox reactionsThe combustion of fossil fuels produces large amounts of carbon emission, thus posing a climate threat due to global warming. (1) Efforts on harnessing excess emitted CO2 back to the carbon cycle via chemical, electrochemical, and photochemical pathways have seen steady development to produce value-added chemicals for energy storage. (1,2) Among them, an environmentally benign electroreduction approach is the most promising one for valorization of CO2 as fuels and chemicals, albeit the fact that sluggish kinetics and lack of selectivity require the design of suitable catalysts. (3,4) Molecular electrocatalysts have well-defined active sites and accurately tailorable structures that allow mechanism-based performance optimization. Among them, several are based on easily available first-row transition metals to catalyze CO2 reduction (CO2RR) via a 2e–/2H+ mechanism to form CO and HCOOH. (5) Nevertheless, examples of molecular catalysts capable of reducing CO2 beyond 2e–/2H+ (e.g., multielectron products) are scarce. A key reason for that is the difficulty in controlling the binding affinity of the catalyst-bound CO intermediate, which often plays a pivotal role in the generation of multielectron/multiproton products. (5,6) Along with this, the complexity of the multielectron/multiproton pathways involving multiple intermediates provides a limited understanding of the reaction mechanism. (5,7) Herein, we would like to highlight several recently reported strategies that show promising CO2RR activity and selectivity toward products beyond 2e–/2H+, such as (i) immobilization of functionalized molecular catalysts over conductive supports, (ii) incorporation of intramolecular hydrogen-bonding groups proximal to the active site, and (iii) the use of light illumination during electrochemical CO2RR in molecular catalysts incorporated within porous hybrid platforms.Initially, Wang et al. reported one of the first examples of a molecular electrocatalyst reducing CO2 to value-added multielectron hydrocarbons. They immobilized a cobalt phthalocyanine catalyst (CoPc, Figure 1a) over multiwalled carbon-nanotubes (CoPc/MWCNTs) and used it as a heterogeneous electrocatalyst that, in aqueous solution, undergoes 6e–/6H+ CO2RR to generate CH3OH. (5) They first compared the catalytic performance of CNT-immobilized iron, cobalt, and nickel phthalocyanine (FePc, CoPc, and NiPc, respectively), as metal-to-CO binding energy, EB(CO), varies with different M–N4, spanning over a range of 1.2 eV and found that cobalt provides moderate CO binding. Therefore, among all three catalysts, only CoPc produced MeOH with a faradaic efficiency (FE) of up to 44% at −0.94 V vs RHE (CO and H2 being the major products for FePc and NiPc). Through scanning transmission electron microscopy (STEM) analysis they have shown that CoPc has molecular level dispersion over the CNT, which is vital for MeOH formation. Otherwise, physical mixtures of CoPc and CNTs showed much less reactivity, despite having higher CoPc content. According to their observation, at lower overpotential, CO was the major CO2RR product, and thus, it was postulated that CO acts as a reactive intermediate toward MeOH formation. Indeed, when an electrocatalytic CO reduction reaction (CORR) using CoPc/MWCNT was performed, it produced MeOH with a FE of 28% at −0.77 V vs RHE. Overall, catalysis goes through a "domino" process where CO2 first reduces to CO, and then undergoes another 4e–/4H+ reduction to MeOH, and the potential-dependent steps of both CO2RR and CORR are very similar. Nonetheless, this catalytic system suffers from rather limited durability. Upon only 1 h of electrolysis, FECH3OH decreased by 18%, while after 4 h of electrolysis, MeOH formation became negligible. UV–visible spectra of the postelectrolysis CoPc molecule from the electrode revealed an undesired reduction of the Pc ligand, eventually leading to hydrogenation of the macrocycle. To avoid the reductive deactivation, Wang and co-workers introduced four electron-donating amino groups in the β position of the CoPc moiety (Figure 1b, CoPc-NH2), which successfully lowered the overpotential and could sustain activity for a longer time with a maximum FECH3OH of 32%.Figure 1Figure 1. Catalysts (a) cobalt phthalocyanine and (b) cobalt phthalocyanine-NH2 at the β position, used by Wang et al. (5) (c) Catalyst FeL2, synthesized by Dey et al. with a second sphere pyridine moiety. (2) (d) Co-MOF-525 building units: CoTCPP linker and Zr6(OH)4O4 node and (e) schematic representation of a photoassisted electrochemical CO2 reduction reaction onto a FTO-Co-MOF-525 electrode by Hod et al. (9) (d) and (e) are reproduced under a CC-BY 4.0 license from ref (9). Copyright 2023 Authors.High Resolution ImageDownload MS PowerPoint SlideAt about the same time, Robert et al. also used the CoPc catalyst and MWCNT mixture with a Nafion binder over carbon paper for the conversion of CO2 to MeOH. (8) Under heterogeneous conditions in 0.5 M KHCO3 solution (pH = 7.2), they obtained only 0.3% FECH3OH at −0.88 V vs RHE, which increased to 2% when they used CO as substrate instead of CO2. However, at pH 13, when CO was used as a substrate, the same CoPc/MWCNT system exhibited 14.3% FECH3OH at −0.68 V vs RHE, i.e., a 50-fold increase in selectivity at a 170 mV lower overpotential, along with a 10-fold increase in catalytic rate. Subsequent HPLC experiments showed that during CORR at pH 13, formaldehyde (HCHO) is formed. At alkaline pH, there is a chance of Cannizzaro reaction, i.e., a disproportionation of HCHO (aldehyde without α hydrogens) to CH3OH and HCOO– causing an overestimation of CH3OH's FE determination. Knowing that, Robert and co-workers carefully evaluated these nonfaradaic CH3OH formations and concluded that their effect is negligible. In addition, a series of control experiments, along with Co K-edge X-ray absorption near-edge structure (XANES) spectra of the CoPc before and after electrolysis proved that the observed reactivity was not due to the decomposition of CoPc into metallic Co nanoparticles, thus signifying the molecular nature of the catalyst.Lately, McCrory et al. further investigated the catalytic properties of the CoPc/MWCNT system using a gas-diffusion electrode (GDE) flow-cell. Compared to a conventional H-cell configuration, performing the electrocatalytic reaction in a CO2-fed GDE setup showed appreciably suppressed activity toward MeOH formation. The key explanation for these results lies at the higher CO2 binding affinity of CoPc compared to its affinity to bind CO, as quantitatively measured in this study. (6) The authors varied the partial current density of MeOH (product of CORR) at −0.70 V vs RHE as a function of the partial pressure of CO (PCO), which ultimately reached a plateau at PCO = 1. Thereafter, using a microkinetic analysis, the binding constant of CO to CoPc (KCO) was determined to be 3.0 atm–1. On the contrary, in the case of a CO2RR reaction with CoPc (where the major product is CO), extracted KCO2 was 11.1 atm–1. The high binding constant ratio of KCO2/KCO = 3.7, provides a thermodynamic explanation for the inefficient MeOH formation on CoPc/MwCNTs during CO2RR, where catalyst-bound CO is preferentially displaced by CO2 molecules before it can be further reduced. Thus, the authors suggested that researchers should look forward in the direction of controlling the local concentration of CO2 by construction of catalyst–polymer composites, or via applying modifications to the coordination environments of CoPc. These strategies will strengthen the CO binding, especially when using GDE flow-cells.As opposed to CoPc, in case of metal porphyrins, up until recently, reports of CO2 reduction into multielectron compounds were only available when conducted under photochemical conditions. (10,11) Lately, however, Dey and co-workers designed a distal superstructure in the molecular framework of iron porphyrins, and were able to stop the dissociation of CO from the metal-bound intermediate and simultaneously activated it for further reduction. In this work, an iron porphyrin having a distal basic pyridine residue was synthesized (FeL2, Figure 1C) and used as homogeneous electrocatalyst for CO reduction to CH4, with 93% FE. (2) Spectro-electrochemistry coupled FTIR (FTIR-SEC) was employed to understand the mechanism of the reaction with in situ detection of the metal–carbonyl species, using 12/13CO isotope sensitive absorption. In CO-saturated CH3CN containing 3% H2O, they identified an FeII–CO species being reduced to FeI–CO at applied potential of −1.75 V vs Fc/Fc+, followed by the reduction of FeI–CO to Fe0-CO at −2.35 V vs Fc/Fc+. Interestingly, while holding the potential at −2.35 V for a long period, an FeII–CHO adduct was detected, which then could be further reduced to CH4. In this case, pyridine mediated hydrogen-bonding between water molecules (i.e., proton source) and FeI–CO intermediate allows its stabilization, and activation for further reduction to CH4 (as evidenced by DFT calculation).In another attempt to achieve multielectron CO2 reduction using porphyrins, our group adopted a different approach, based on a photoassisted electrocatalysis pathway for multiproton/multielectron CO2RR. To do so, we have utilized photoactive Co-porphyrin (CoTCPP)-based metal–organic framework (MOF) films (Co-MOF-525). Under 1-sun light illumination (100 mW/cm2), the MOF film can sustain large quantities of long-lived oxidized charged carriers during photocathodic operation and performed a 8e–/8H+ reduction of CO2 to CH4 (in 80/20 (%v/v) CH3CN–H2O with a LiClO4 electrolyte). (9) Subsequent, photoassisted chronoamperometric measurements revealed that in the potential window of −0.39 to −0.64 V, CH4 and CO were produced during CO2RR, with a maximum FECH4 being 14% at −0.49 V, while FECO was only 2%. Yet, in the absence of light illumination, both products were formed in a very negligible amount. At more cathodic potentials, a hydrogen evolution reaction (HER) became more prominent and significantly suppressed CO2RR. Generally, CoITCPP is the CO2RR active state that binds CO2 and undergoes 2e–/2H+ reduction to CO. However, thin layer spectro-electrochemical measurements revealed a different mechanism that leads to the unexpected CH4 production. Under dark electrolysis conditions, spectro-electrochemistry analysis showed the formation of bands attributed to CoIITCPP and CoIIITCPP+, while measurements at more cathodic potentials showed the formation of a new band corresponding to CO2RR active species, CoITCPP−. Surprisingly, in photoassisted electrolysis conditions, the formation of a broad band at 460 nm was noticed, suggesting the existence of a higher oxidation form of the catalyst, namely, CoIIITCPP2+, which was the product of a porphyrin ring oxidation. Here, with an increase in the cathodic potential, the CoIIITCPP2+ band decreased in intensity, while the CoIITCPP and CoIIITCPP+ bands remained unchanged throughout the course of the reaction. In other words, in these conditions, MOF-525 maintains a high concentration of CoIIITCPP+ species (via photo-oxidative accumulation of holes), which is known to stabilize CO by preferentially binding with it, (12) a crucial step that allows its further reduction to CH4.To conclude, despite severe challenges posed in the electrocatalytic conversion of CO2 to multielectron products, successful reports of molecular catalysts capable of CO2RR beyond 2e–/2H+ have increased lately. The results highlighted herein could help pave the way toward (i) rational catalyst design, (ii) improved structure–function correlation studies, and (iii) identification of key mechanistic factors necessary to understand molecular catalyst operation both in homogeneous as well as heterogeneous configurations. Nevertheless, realizing the next-generation of molecular catalytic systems will have to involve new approaches for the stabilization of key reactive intermediates while developing means for their assembly onto porous functional supports that allows the incorporation of secondary-sphere interactions to stir the CO2RR path toward the desired products.Author InformationClick to copy section linkSection link copied!Corresponding AuthorsArnab Ghatak - Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel; https://orcid.org/0000-0003-3027-9359; Email: email protectedIdan Hod - Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel; https://orcid.org/0000-0003-4837-8793; Email: email protectedAuthor ContributionsThe manuscript was written through contribution of all the authors. All authors have given approval to the final version of the manuscript.NotesThe authors declare no competing financial interest.AcknowledgmentsClick to copy section linkSection link copied!This work is supported by the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Program with Grant Agreement No. 947665. This work was also partially supported by Israel Science Foundation (ISF; Grant No. 1267/22).ReferencesClick to copy section linkSection link copied! This article references 12 other publications. 1She, X.; Wang, Y.; Xu, H.; Chi Edman Tsang, S.; Ping Lau, S. Challenges and Opportunities in Electrocatalytic CO2 Reduction to Chemicals and Fuels. Angew. Chem., Int. Ed. 2022, 61 (49), e202211396 DOI: 10.1002/anie.202211396 Google ScholarThere is no corresponding record for this reference.2Patra, S.; Bhunia, S.; Ghosh, S.; Dey, A. Outer-Coordination-Sphere Interaction in a Molecular Iron Catalyst Allows Selective Methane Production from Carbon Monoxide. ACS Catal. 2024, 14 (10), 7299– 7307, DOI: 10.1021/acscatal.3c06112 Google ScholarThere is no corresponding record for this reference.3Cao, R. Across the Board: Rui Cao on Electrocatalytic CO2 Reduction. ChemSusChem 2022, 15 (21), e202201788 DOI: 10.1002/cssc.202201788 Google ScholarThere is no corresponding record for this reference.4Francke, R.; Schille, B.; Roemelt, M. Homogeneously Catalyzed Electroreduction of Carbon Dioxide─Methods, Mechanisms, and Catalysts. Chem. Rev. 2018, 118 (9), 4631– 4701, DOI: 10.1021/acs.chemrev.7b00459 Google ScholarThere is no corresponding record for this reference.5Wu, Y.; Jiang, Z.; Lu, X.; Liang, Y.; Wang, H. Domino electroreduction of CO2 to methanol on a molecular catalyst. Nature 2019, 575 (7784), 639– 642, DOI: 10.1038/s41586-019-1760-8 Google ScholarThere is no corresponding record for this reference.6Yao, L.; Rivera-Cruz, K. E.; Zimmerman, P. M.; Singh, N.; McCrory, C. C. L. Electrochemical CO2 Reduction to Methanol by Cobalt Phthalocyanine: Quantifying CO2 and CO Binding Strengths and Their Influence on Methanol Production. ACS Catal. 2024, 14 (1), 366– 372, DOI: 10.1021/acscatal.3c04957 Google ScholarThere is no corresponding record for this reference.7Shen, J.; Kortlever, R.; Kas, R.; Birdja, Y. Y.; Diaz-Morales, O.; Kwon, Y.; Ledezma-Yanez, I.; Schouten, K. J. P.; Mul, G.; Koper, M. T. M. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin. Nat. Commun. 2015, 6 (1), 8177, DOI: 10.1038/ncomms9177 Google ScholarThere is no corresponding record for this reference.8Boutin, E.; Wang, M.; Lin, J. C.; Mesnage, M.; Mendoza, D.; Lassalle-Kaiser, B.; Hahn, C.; Jaramillo, T. F.; Robert, M. Aqueous Electrochemical Reduction of Carbon Dioxide and Carbon Monoxide into Methanol with Cobalt Phthalocyanine. Angew. Chem., Int. Ed. 2019, 58 (45), 16172– 16176, DOI: 10.1002/anie.201909257 Google ScholarThere is no corresponding record for this reference.9Ifraemov, R.; Mukhopadhyay, S.; Hod, I. Photo-Assisted Electrochemical CO2 Reduction to CH4 Using a Co-Porphyrin-Based Metal–Organic Framework. Sol. RRL 2023, 7 (5), 2201068 DOI: 10.1002/solr.202201068 Google ScholarThere is no corresponding record for this reference.10Rao, H.; Lim, C. H.; Bonin, J.; Miyake, G. M.; Robert, M. Visible-Light-Driven Conversion of CO2 to CH4 with an Organic Sensitizer and an Iron Porphyrin Catalyst. J. Am. Chem. Soc. 2018, 140 (51), 17830– 17834, DOI: 10.1021/jacs.8b09740 Google ScholarThere is no corresponding record for this reference.11Rao, H.; Schmidt, L. C.; Bonin, J.; Robert, M. Visible-light-driven methane formation from CO2 with a molecular iron catalyst. Nature 2017, 548 (7665), 74– 77, DOI: 10.1038/nature23016 Google ScholarThere is no corresponding record for this reference.12Mu, X. H.; Kadish, K. M. Oxidative electrochemistry of cobalt tetraphenylporphyrin under a CO atmosphere. Interaction between carbon monoxide and electrogenerated (TPP) Co+ in nonbonding media. Inorg. Chem. 1989, 28 (19), 3743– 3747, DOI: 10.1021/ic00318a025 Google ScholarThere is no corresponding record for this reference.Cited By Click to copy section linkSection link copied!This article has not yet been cited by other publications.Download PDFFiguresReferencesOpen PDF Get e-AlertsGet e-AlertsArtificial PhotosynthesisCite this: Artif. Photosynth. 2024, XXXX, XXX, XXX-XXXClick to copy citationCitation copied!https://doi.org/10.1021/aps.4c00011Published August 30, 2024 Publication History Received 7 July 2024Accepted 6 August 2024Revised 1 August 2024Published online 30 August 2024© 2024 The Authors. Co-published by Dalian Institute of Chemical Physics, CAS, Westlake University, and American Chemical Society. This publication is licensed under CC-BY-NC-ND 4.0 . License Summary*You are free to share (copy and redistribute) this article in any medium or format within the parameters below:Creative Commons (CC): This is a Creative Commons license.Attribution (BY): Credit must be given to the creator.Non-Commercial (NC): Only non-commercial uses of the work are permitted. No Derivatives (ND): Derivative works may be created for non-commercial purposes, but sharing is prohibited. View full license*DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. Article Views-Altmetric-Citations-Learn about these metrics closeArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.Recommended Articles FiguresReferencesFigure 1Figure 1. Catalysts (a) cobalt phthalocyanine and (b) cobalt phthalocyanine-NH2 at the β position, used by Wang et al. (5) (c) Catalyst FeL2, synthesized by Dey et al. with a second sphere pyridine moiety. (2) (d) Co-MOF-525 building units: CoTCPP linker and Zr6(OH)4O4 node and (e) schematic representation of a photoassisted electrochemical CO2 reduction reaction onto a FTO-Co-MOF-525 electrode by Hod et al. (9) (d) and (e) are reproduced under a CC-BY 4.0 license from ref (9). Copyright 2023 Authors.High Resolution ImageDownload MS PowerPoint SlideReferences This article references 12 other publications. 1She, X.; Wang, Y.; Xu, H.; Chi Edman Tsang, S.; Ping Lau, S. Challenges and Opportunities in Electrocatalytic CO2 Reduction to Chemicals and Fuels. Angew. Chem., Int. Ed. 2022, 61 (49), e202211396 DOI: 10.1002/anie.202211396 There is no corresponding record for this reference.2Patra, S.; Bhunia, S.; Ghosh, S.; Dey, A. Outer-Coordination-Sphere Interaction in a Molecular Iron Catalyst Allows Selective Methane Production from Carbon Monoxide. ACS Catal. 2024, 14 (10), 7299– 7307, DOI: 10.1021/acscatal.3c06112 There is no corresponding record for this reference.3Cao, R. Across the Board: Rui Cao on Electrocatalytic CO2 Reduction. ChemSusChem 2022, 15 (21), e202201788 DOI: 10.1002/cssc.202201788 There is no corresponding record for this reference.4Francke, R.; Schille, B.; Roemelt, M. Homogeneously Catalyzed Electroreduction of Carbon Dioxide─Methods, Mechanisms, and Catalysts. Chem. Rev. 2018, 118 (9), 4631– 4701, DOI: 10.1021/acs.chemrev.7b00459 There is no corresponding record for this reference.5Wu, Y.; Jiang, Z.; Lu, X.; Liang, Y.; Wang, H. Domino electroreduction of CO2 to methanol on a molecular catalyst. Nature 2019, 575 (7784), 639– 642, DOI: 10.1038/s41586-019-1760-8 There is no corresponding record for this reference.6Yao, L.; Rivera-Cruz, K. E.; Zimmerman, P. M.; Singh, N.; McCrory, C. C. L. Electrochemical CO2 Reduction to Methanol by Cobalt Phthalocyanine: Quantifying CO2 and CO Binding Strengths and Their Influence on Methanol Production. ACS Catal. 2024, 14 (1), 366– 372, DOI: 10.1021/acscatal.3c04957 There is no corresponding record for this reference.7Shen, J.; Kortlever, R.; Kas, R.; Birdja, Y. Y.; Diaz-Morales, O.; Kwon, Y.; Ledezma-Yanez, I.; Schouten, K. J. P.; Mul, G.; Koper, M. T. M. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin. Nat. Commun. 2015, 6 (1), 8177, DOI: 10.1038/ncomms9177 There is no corresponding record for this reference.8Boutin, E.; Wang, M.; Lin, J. C.; Mesnage, M.; Mendoza, D.; Lassalle-Kaiser, B.; Hahn, C.; Jaramillo, T. F.; Robert, M. Aqueous Electrochemical Reduction of Carbon Dioxide and Carbon Monoxide into Methanol with Cobalt Phthalocyanine. Angew. Chem., Int. Ed. 2019, 58 (45), 16172– 16176, DOI: 10.1002/anie.201909257 There is no corresponding record for this reference.9Ifraemov, R.; Mukhopadhyay, S.; Hod, I. Photo-Assisted Electrochemical CO2 Reduction to CH4 Using a Co-Porphyrin-Based Metal–Organic Framework. Sol. RRL 2023, 7 (5), 2201068 DOI: 10.1002/solr.202201068 There is no corresponding record for this reference.10Rao, H.; Lim, C. H.; Bonin, J.; Miyake, G. M.; Robert, M. Visible-Light-Driven Conversion of CO2 to CH4 with an Organic Sensitizer and an Iron Porphyrin Catalyst. J. Am. Chem. Soc. 2018, 140 (51), 17830– 17834, DOI: 10.1021/jacs.8b09740 There is no corresponding record for this reference.11Rao, H.; Schmidt, L. C.; Bonin, J.; Robert, M. Visible-light-driven methane formation from CO2 with a molecular iron catalyst. Nature 2017, 548 (7665), 74– 77, DOI: 10.1038/nature23016 There is no corresponding record for this reference.12Mu, X. H.; Kadish, K. M. Oxidative electrochemistry of cobalt tetraphenylporphyrin under a CO atmosphere. Interaction between carbon monoxide and electrogenerated (TPP) Co+ in nonbonding media. Inorg. Chem. 1989, 28 (19), 3743– 3747, DOI: 10.1021/ic00318a025 There is no corresponding record for this reference.