Nano-CaCO3 templated porous carbons anchored with Fe single atoms enable high-efficiency N2 electroreduction to NH3

The traditional Haber-Bosch N 2 fixation process suffers from rigorous reaction conditions and massive CO 2 emission. By contrast, N 2 electroreduction by water to the direct production of NH 3 can be conducted at room temperature and atmospheric pressure, and thus has been attracting increasingly attention. Herein, we develop a nano-CaCO 3 template route for the synthesis of Fe, N co-doped porous carbon materials from zeolitic imidazolate framework-8 (ZIF-8). The Fe atoms are atomically dispersed in the skeleton of carbon and bonded with four nitrogen atoms . Interestingly, the morphology and pore structure of these carbons have notable effects on their performance for the electrocatalytic reduction of N 2 . With an optimized morphology and pore structure tuned by the addition of nano-CaCO 3 template, the ZIF-8 derived Fe, N co-doped carbon catalyst shows a Faradaic efficiency of 13.14% and a NH 3 yield as high as 13.01 µg h −1 mg cat −1 (−0.2 vs . reversible hydrogen electrode) for N 2 reduction reaction in 0.1 M KOH aqueous electrolyte . Morphology engineering strategy may open a new path to designing and synthesizing high-performance carbon-based catalysts for the electroreduction of N 2 to NH 3 .