Playing Domino with Carbon: Electrochemical CO2 Reduction to Methanol with Cobalt Phthalocyanine
4 affiliations
- 1National Research Council (CNR), Institute of Structure of Matter (ISM), via del Fosso del Cavaliere, 100, Rome, Italy, 00133
- 2Sapienza University of Rome, Department of Chemistry, Piazzale Aldo Moro 5, Rome, Italy, 00185
- 3National Research Council (CNR), Institute of Structure of Matter (ISM), Strada provinciale 35d/9, Montelibretti, Italy, 00010
- 4University of Rome “Tor Vergata”, CHOSE, Centre for Hybrid and Organic Solar Energy, via del Politecnico 1, Rome, Italy, 00133
Abstract
Electrochemical reduction of carbon dioxide to methanol represents one of the most demanding transformations in CO 2 conversion, requiring the management of a six-electron, six-proton sequence while suppressing competing pathways toward carbon monoxide, formate, and hydrogen evolution. Among molecular electrocatalysts, cobalt phthalocyanine (CoPc) has emerged as a unique molecular platform capable of extending CO 2 reduction beyond CO through a domino-like cascade of protoncoupled electron transfer steps. Its square-planar Co-N 4 coordination environment provides metalcentered redox couples that enables CO 2 activation at the Co(I) state and stabilizes key intermediates within a narrow adsorption-energy window compatible with further hydrogenation. This review examines the fundamental and applied aspects of CoPc-mediated electrochemical CO 2 and CO reduction to methanol. The effects of ring substitution, axial ligation, and support-induced distortions on redox potentials, orbital interactions, and intermediate binding energetics were analyzed. Particular attention was devoted to solvation-coupled proton-coupled electron transfer, cation effects, and electric double-layer structure, which collectively governed CO retention and sequential hydrogenation toward CH 3 OH. Immobilization strategies on carbon nanotubes and related supports were discussed in relation to molecular dispersion, electronic coupling, and stability under flow-cell operation. Finally, scalability and sustainability are assessed through life-cycle considerations and green-chemistry metrics applied to phthalocyanine synthesis and device integration. Despite these advances, the field remains limited by catalyst deactivation, incomplete comparability among electrochemical setups and the frequent lack of standardized metrics for methanol quantification under device-relevant conditions. By connecting molecular design interfacial microenvironment, reactor architecture and sustainable catalyst synthesis, this review identifies the key directions required to move CoPc-based systems from promising molecular models toward technologically credible CO 2 -to-methanol electrolysis.
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BibTeX
@misc{raglione2026playing,
title = {{Playing Domino with Carbon: Electrochemical CO2 Reduction to Methanol with Cobalt Phthalocyanine}},
author = {Venanzio Raglione and Federica Palmeri and Abdolhamid Khodadadi and Gloria Zanotti and Mahmoud Zendehdel and Roberto Flammini and Giorgio Contini},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009603/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009603/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Playing Domino with Carbon: Electrochemical CO2 Reduction to Methanol with Cobalt Phthalocyanine
AU - Venanzio Raglione
AU - Federica Palmeri
AU - Abdolhamid Khodadadi
AU - Gloria Zanotti
AU - Mahmoud Zendehdel
AU - Roberto Flammini
AU - Giorgio Contini
PY - 2026
DA - 2026/09/29
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009603/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009603/v1
AB - Electrochemical reduction of carbon dioxide to methanol represents one of the most demanding transformations in CO 2 conversion, requiring the management of a six-electron, six-proton sequence while suppressing competing pathways toward carbon monoxide, formate, and hydrogen evolution. Among molecular electrocatalysts, cobalt phthalocyanine (CoPc) has emerged as a unique molecular platform capable of extending CO 2 reduction beyond CO through a domino-like cascade of protoncoupled electron transfer steps. Its square-planar Co-N 4 coordination environment provides metalcentered redox couples that enables CO 2 activation at the Co(I) state and stabilizes key intermediates within a narrow adsorption-energy window compatible with further hydrogenation. This review examines the fundamental and applied aspects of CoPc-mediated electrochemical CO 2 and CO reduction to methanol. The effects of ring substitution, axial ligation, and support-induced distortions on redox potentials, orbital interactions, and intermediate binding energetics were analyzed. Particular attention was devoted to solvation-coupled proton-coupled electron transfer, cation effects, and electric double-layer structure, which collectively governed CO retention and sequential hydrogenation toward CH 3 OH. Immobilization strategies on carbon nanotubes and related supports were discussed in relation to molecular dispersion, electronic coupling, and stability under flow-cell operation. Finally, scalability and sustainability are assessed through life-cycle considerations and green-chemistry metrics applied to phthalocyanine synthesis and device integration. Despite these advances, the field remains limited by catalyst deactivation, incomplete comparability among electrochemical setups and the frequent lack of standardized metrics for methanol quantification under device-relevant conditions. By connecting molecular design interfacial microenvironment, reactor architecture and sustainable catalyst synthesis, this review identifies the key directions required to move CoPc-based systems from promising molecular models toward technologically credible CO 2 -to-methanol electrolysis.
ER -