The electrocatalytic reduction of CO₂ (CO₂RR) to CO is an important component of emerging Carbon Capture and Utilization (CCU) technologies. This process often relies on expensive and rare metals such as silver and gold-based materials for high selectivity and conversion rate to CO^1,2. It is desired to move away from these metals towards earth-abundant solid materials (e.g., carbon-based) which may serve as heterogeneous electrocatalysts for CO₂RR. Herein, a series of novel carbon-based materials with exceptional selectivity/activity for the targeted production of CO is presented. This new class of hybrid catalyst materials have high CO₂RR activity which is comparable to the state of the art atomically dispersed Metal-N-C synthesized by the sacrificial support method (SSM). The advantage of this new class of catalysts is that the use of harsh solvents such as nitric acid and potassium hydroxide which are usually required to remove the silica precursor is completely avoided. Not only does this make the immediate process more environmentally friendly, but it also significantly shortens the catalyst synthesis time which increases its industrial viability. The structure and activity of a series of catalysts with different metallic dopants (Fe, Co, Ni, Mn) are investigated. Using this new synthesis technique, a faradaic efficiency for CO formation (FE_co) of 96.5 % at -0.3 V vs. RHE is achieved. FE_co remains greater than 75 % over the potential range studied from -0.3 V to -1.1 V vs. RHE. By comparison, Fe-N-C by SSM method reaches a maximum FE_co of 94.4 % at -0.7 V vs. RHE and FE_co remains greater than 85 % over the same potential range.

References

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