Nitrogen (N), Phosphorus (P)-Codoped Porous Carbon as a Metal-Free Electrocatalyst for N₂ Reduction under Ambient Conditions

Abstract

The electrocatalytic conversion of nitrogen gas at ambient conditions represents a novel approach for ammonia synthesis to the sustainable society. It is critical to understand the detailed pathways and mechanisms of this promising process to develop a highly efficient catalyst. Herein, the N, P co-doping carbon (NP-C-MOF-5) catalyst was prepared for electrocatalytic N2 reduction in acid electrolytes under ambient temperatures and pressures. Experimental results showed that there are two products including NH3 and N2H4·H2O on the NP-C-MOF-5 cathode at −0.1 V versus RHE with the yield of 1.08 and 5.77 × 10–4 μg h–1 mgcat. –1, respectively. Moreover, an electrocatalytic pathway on NP-C-MOF-5 was investigated by the electrochemical in situ Fourier transform infrared technique. The results confirmed the formation of N2H y (1 ≤ y ≤ 4) intermediates on NP-C-MOF-5 cathode surfaces, suggesting an associative pathway for the N2 reduction reaction.

Defective S/N co-doped carbon cloth via a one-step process for effective electroreduction of nitrogen to ammonia

“…The technique of in situ FTIR is powerful for detecting the transient states in the NRR process, through which the reaction pathway can be revealed directly. 19,20,68 The NRR associated reaction path of S/N-codoped carbon cloth (N^N / -N^N-H / -HN]NH / -HN-NH 2 / NH-NH 3 ) is consistent with many doped carbon materials in recent reports. 19,20,69…”

“…Furthermore, it is considered that co-doping carbon materials with two kinds of heteroatoms may co-activate the adjacent C atom and construct some unexpected electronic structures, which usually provides much more active sites than that of one heteroatom doping, and enhances the NRR performance eventually. However, dualdopant pairs reported in co-doped carbon materials for NRR are merely restricted to N-P 19,20 and N-B 21,22 couples. Sulfur/ nitrogen co-doped carbon has gained remarkable progress in multiple electrocatalysis elds, including oxygen reduction reaction (ORR), 23 oxygen evolution reaction (OER), 24 and hydrogen evolution reaction (HER).…”

Solid solution for catalytic ammonia synthesis from nitrogen and hydrogen gases at 50 °C

“…he Haber-Bosch process currently enables the provision of food for over 70% of the world's population, consuming 2% of global energy and generating 3% of global CO 2 emissions 1,2 . These values would steeply increase by a rapid increase of the human population.…”

“…1.0 H 1.0 solid solution formed on CaH 2 -BaF 2 mixtures, CaF x H 2-x solid solution (denoted as CaF x H 2-x -CaF 2 ) was prepared by heating mixtures of orthorhombic CaH 2 and cubic CaF 2 at 550°C, a conventional method17 . XRD patterns of CaF x H 2-x -CaF 2 (1.0 ≤ x ≤ 1.6) (Supplementary Fig.…”

Recent Advances in Noble‐Metal‐Free Catalysts for Electrocatalytic Synthesis of Ammonia under Ambient Conditions

“…In addition, N, P co-doping porous carbon was also fabricated and showed two products, including NH 3 and N 2 H 4 •H 2 O at À 0.1 V, with a yield of 1.08 and 5.77 × 10 À 4 μg h À 1 mg cat À 1 , respectively. [94] The incorporation of BÀ N pairs in the carbon matrix would be the active triggers, and the edge carbon atoms near to the BÀ N pairs are the active sites toward NRR. BÀ N pairs enriched defective carbon nanosheets achieved NH 3 formation rate (7.75 μg h À 1 mg cat À 1 ) and FE (13.79%).…”