Carbon nanotubes with fluorine-rich surface as metal-free electrocatalyst for effective synthesis of urea from nitrate and CO2

Turning Waste into Wealth: Sustainable Production of High-Value-Added Chemicals from Catalytic Coupling of Carbon Dioxide and Nitrogenous Small Molecules

“…Liu et al developed CNTs with a fluorine-rich surface (F-CNT-300) as an advanced metal-free catalyst for effective synthesis of urea from nitrate and CO 2 . 94 According to X-ray photoelectron spectroscopy analysis, F dopants mainly exist in the form of C-F 2 (93.9 at.%), which is thus considered as the model for DFT calculations. The results show that the formation of *CO and *NH 2 intermediates is favorable on C-F 2 moieties and the formation energy of *CONH 2 is much lower than that on undoped C active sites, indicating the facilitation of the C−N coupling reaction.…”

“…Experimentally, the Cu-GS-800 catalyst is more active for urea synthesis, achieving a production rate of 1840 μg h –1 mg –1 at −1.0 V vs RHE and a FE of 28% at −0.9 V vs RHE. Liu et al developed CNTs with a fluorine-rich surface (F-CNT-300) as an advanced metal-free catalyst for effective synthesis of urea from nitrate and CO 2 . According to X-ray photoelectron spectroscopy analysis, F dopants mainly exist in the form of C-F 2 (93.9 at.%), which is thus considered as the model for DFT calculations.…”

High-efficiency electrosynthesis of urea over bacterial cellulose regulated Pd–Cu bimetallic catalyst

“…[16][17][18][19][20][21][22][23][24][25][26][27][28] In comparion with N2 reactant, the superiorities of NO3 − and NO2 − as the reactants are high solubility in aqueous solution, lower dissociation energy of N=O bond (204 KJ mol −1 ), which enable more efficient C−N coupling reaction for urea production. [16][17][18][19][20][21][22][23][24][25][26][27][28] Besides of this, development of high-efficiency electrocatalysts is also critically important for urea synthesis. To date, precious and non-precious metals based electrocatalysts have been fabricated and investigated for electrocatalytic coupling of NO3 − and NO2 − (or NO) and CO2 to efficiently synthesize urea at ambient conditions, exhibiting high electrocatalytic activities.…”

Emerging p-Block-Element-Based Electrocatalysts for Sustainable Nitrogen Conversion

“…This lowered the energy barrier for the protonation of the • CO 2 NH 2 intermediate, which was suggested to be the RDS by the DFT calculations for the overall urea formation (Figure g). Hu et al developed the carbon nanotubes with a fluorine-rich surface (F-CNT) as a metal-free electrocatalyst for urea synthesis from CO 2 and nitrate, during which the first C–N bond is formed by coupling • CO and • NH 2 intermediates . The catalyst delivered a high urea yield rate of 6.36 mmol h –1 g cat –1 with a FE of 18.0%, thereby even outclassing some metal-based materials.…”

“…Hu et al developed the carbon nanotubes with a fluorine-rich surface (F-CNT) as a metal-free electrocatalyst for urea synthesis from CO 2 and nitrate, during which the first C−N bond is formed by coupling • CO and • NH 2 intermediates. 157 The catalyst delivered a high urea yield rate of 6.36 mmol h −1 g cat −1 with a FE of 18.0%, thereby even outclassing some metal-based materials.…”