This study investigates the electrocatalytic reduction of carbon dioxide (CO₂RR) using a series of cobalt complexes with TPA ligands modified by amino groups in the secondary coordination sphere. By combining electrochemical experiments, electrochemistry-coupled electrospray ionization mass spectrometry (EC-ESI-MS), and density functional theory (DFT) calculations, the researchers identify and characterize key reaction intermediates in CO₂RR and the competing hydrogen evolution reaction (HER). The study reveals in situ modifications of the amino substituents of the cobalt complexes into carbamates, which alter the catalytic properties of the complexes and open an alternative, faster HER pathway. The interplay of three catalytic cycles, supported by DFT calculations, explains the trends in CO₂RR and HER for the cobalt complexes. The study highlights the importance of a molecular perspective in understanding the electrocatalytic activation of small molecules, as demonstrated by the EC-ESI-MS technique. The results show that the number of amino groups in the secondary coordination sphere of the cobalt complexes influences the reaction pathways and product selectivity. The study also demonstrates that the carbamate modification of the ligands enhances the hydrogen evolution reaction, leading to increased H₂ production. The findings provide insights into the mechanisms of CO₂RR and HER, and the role of ligand modifications in catalytic activity. The study underscores the value of EC-ESI-MS in elucidating the fate of catalysts during electrocatalytic reactions.This study investigates the electrocatalytic reduction of carbon dioxide (CO₂RR) using a series of cobalt complexes with TPA ligands modified by amino groups in the secondary coordination sphere. By combining electrochemical experiments, electrochemistry-coupled electrospray ionization mass spectrometry (EC-ESI-MS), and density functional theory (DFT) calculations, the researchers identify and characterize key reaction intermediates in CO₂RR and the competing hydrogen evolution reaction (HER). The study reveals in situ modifications of the amino substituents of the cobalt complexes into carbamates, which alter the catalytic properties of the complexes and open an alternative, faster HER pathway. The interplay of three catalytic cycles, supported by DFT calculations, explains the trends in CO₂RR and HER for the cobalt complexes. The study highlights the importance of a molecular perspective in understanding the electrocatalytic activation of small molecules, as demonstrated by the EC-ESI-MS technique. The results show that the number of amino groups in the secondary coordination sphere of the cobalt complexes influences the reaction pathways and product selectivity. The study also demonstrates that the carbamate modification of the ligands enhances the hydrogen evolution reaction, leading to increased H₂ production. The findings provide insights into the mechanisms of CO₂RR and HER, and the role of ligand modifications in catalytic activity. The study underscores the value of EC-ESI-MS in elucidating the fate of catalysts during electrocatalytic reactions.