Imine‐Nitrogen‐Doped Carbon Nanotubes for the Electrocatalytic Reduction of Flue Gas CO₂

Abstract

Imine-nitrogen-doped carbon nanotubes (NCNTs) were prepared by pyrolysis using polyaniline as a major nitrogen source. They can electrocatalytically reduce CO 2 to CO with high selectivity and efficiency. The current density of CO presented a volcanic distribution in the applied potential between À 0.53 and À 0.93 V (vs RHE), reaching 13.8 mA • cm À 2 at À 0.83 V. The maximum Faraday efficiency reached 93 % at À 0.63 V, and the current density of CO was 6.8 mA • cm À 2 . Furthermore, the catalyst can directly reduce CO 2 in simulated flue gas (15 % CO 2, 77 % N 2 and 8 % O 2 ) and exhibited a high CO FE of 70 %. The high catalytic activity originates from rich content of iminenitrogen in NCNTs, serving as the active sites for catalysis.

Challenges and Opportunities in Electrocatalytic CO2Reduction to Chemicals and Fuels

“…Additionally, low-concentration CO 2 electroreduction should be mentioned because of the severe energy input for CO 2 capture and the possible net negative CO 2 emissions. [219][220][221] However, directly electroreducing low-concentration CO 2 suffers from low activity and selectivity. Recently, Kang and co-workers successfully demonstrated the direct and efficient electroreduction of fuel gas CO 2 at a low concentration (15 % CO 2 , 8 % O 2 , and 77 % N 2 ) by an amine-functionalized strategy that enriches the local CO 2 concentration on the catalyst surface, [219,220] which would greatly stimulate the industrial application of the ECO 2 R technology.…”

“…Additionally, low‐concentration CO 2 electroreduction should be mentioned because of the severe energy input for CO 2 capture and the possible net negative CO 2 emissions [219–221] . However, directly electroreducing low‐concentration CO 2 suffers from low activity and selectivity.…”

Review on Heteroatom Doping Carbonaceous Materials Toward Electrocatalytic Carbon Dioxide Reduction

“…Recently, Shi et al [64] have prepared NCNTs with polyaniline as the main N source and used them for the electrocatalytic reduction of CO 2 to CO. At an overpotential of − 0.83 V (vs. RHE), the partial current density of CO can reach 13.8 mA/cm 2 . At an overpotential of − 0.63 V (vs. RHE), the FE reaches a maximum value of 93%.…”

Polydopamine‐Derived Carbon Catalysts with Optimized Structure‐Activity Design towards Electrochemical CO2 Reduction to CO

“…Many metal‐based electrocatalysts for CO 2 RR have been reported, including Pd, Ag, Au, Fe and their derivates [5] . Among the nonmetallic electrocatalysts, nitrogen carbon catalysts, especially the nitrogen doped graphene, [6] nitrogen doped carbon nanotubes, [7] nitrogen doped porous carbon, [8] have been developed for CO 2 RR due to their surface tunability, structural diversity and low cost [2a,9] …”

“…Many metal-based electrocatalysts for CO 2 RR have been reported, including Pd, Ag, Au, Fe and their derivates. [5] Among the nonmetallic electrocatalysts, nitrogen carbon catalysts, especially the nitrogen doped graphene, [6] nitrogen doped carbon nanotubes, [7] nitrogen doped porous carbon, [8] have been developed for CO 2 RR due to their surface tunability, structural diversity and low cost. [2a,9] For the preparation of nitrogen doped carbon, the precursors and the calcination condition would directly influence the chemical structures and electrochemical properties of synthetic electrocatalysts.…”