Carbon dioxide (CO 2 ) is an environmentally harmful "greenhouse gas" that is present in abundant quantities in the Earth's atmosphere. Due to the stability of its structure, it is notoriously regarded as an inert molecule that will only react under harsh conditions such as high temperature or pressure. Electrochemical reduction of CO 2 to value-added materials is a sustainable and potentially profitable way to curb greenhouse gas emissions; however, the challenge of amassing a sizable CO 2 concentration in the active medium persists. Here, we find that various amines, already known to be effective absorbents for CO 2 through the formation of carbamates, can be used directly as substrates for selectively reducing CO 2 to carbon monoxide (CO) at room temperature and ambient pressure. Several primary amines were evaluated using glassy carbon and copper working electrodes for systematic comparison. Here, we demonstrated that use of copper electrodes dramatically enhances current density (up to −18.4 mA/cm 2 at −0.76 V vs RHE) compared to glassy carbon electrodes (−0.63 mA/cm 2 ) using ethylenediamine (EDA) as the catalyst. Moreover, the faradic efficiency was significantly increased from 2.3% to 58%. This concrete finding shows potential to enhance amine catalytic activity for efficient CO 2 reduction. This research has introduced a potentially more sustainable and green method for carbon capture and reduction systems. KEYWORDS: CO 2 conversion, CO 2 capture, Electroreduction of CO 2 , CO 2 utilization, Green chemistry, CO 2 RR and Copper

Metallo-porphyrin complexes such as cobalt and iron porphyrins (CoP and FeP) have shown potential as electrocatalysts for CO 2 reduction. Here we report that introducing amino substituents enhances the electrocatalytic activity of these systems toward CO 2 reduction through a dual active site approach. We developed a flexible synthesis of Coand Fe-porphyrins having variable amino groups and found that monoamino FeP reduces CO 2 to carbon monoxide (CO) at ambient pressure and temperature with competitive turnover numbers (TONs). This efficiency enhancement approach opens a new path to designing and optimizing next generation homogeneous catalysts.

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