Ammonium Carbamate Research Articles

Molecule‐level Design to Form Pocket Structures for Improving Amine Efficiency in CO2 Capture

AbstractSolid amine adsorbents represent a promising class of CO2 sorbents, but their amine efficiency is limited by the inaccessibility of peripheral amines. The surface of mesocellular silica foam (MCF) is functionalized with the mixture of short‐chain 3‐Glycidyloxypropyl) triethoxysilane (GPTES) and long‐chain Octadecyltrimethoxysilane (OTMS), forming pocket structures on the support surface, thereby exposing more amine sites and enhancing the amine efficiency of polyethylenimine (PEI). The resulting adsorbent demonstrates a high CO2 adsorption capacity (5.02 mmol g−1 at 50 °C, 10 vol.% CO2, and 50%RH), high amine efficiency (0.43 at the dry condition), outstanding cyclic stability (0.5% performance decline per cycle under the conditions of dry CO2 regeneration), and fast adsorption kinetics (15 min for adsorption saturation at 50 °C). First‐principles calculations and CO2 temperature‐programmed desorption (TPD) experiments demonstrate that the introduction of GPTES and OTMS is beneficial to decreasing adsorption energy and forming paired carbamic acid states and ammonium carbamate states.

Solvent Effect on Decomposition Kinetics of Ammonium Carbamate for a Chemical Heat Pump

Solvent Effect on Decomposition Kinetics of Ammonium Carbamate for a Chemical Heat Pump

Mechanism investigation of direct electrochemical reduction of CO2-loaded 2-(ethylamino)ethanol solution into CO

Carbon capture and utilization (CCU) has attracted considerable interest recently as CO2 emission and global warming have greatly affected various aspects of the environment, economy, and society. However, energy consumption during CCU must be substantially reduced. In this study, we propose an alternative approach using electrochemical reduction to directly convert CO2-loaded amine solutions into CO. The effects of the electrodes, temperature, potential, and CO2 loading on the Faradaic efficiency (FE) of CO were comprehensively investigated. The Ag NPs/CP electrode showed good catalytic performance on the electrochemical reduction of CO2-loaded amine solution to CO. By comparing the chemical composition in the solution before and after the electrochemical reaction, we determined that the main source of CO might be free CO2, which is mainly converted from bicarbonate rather than carbamate. In addition, electrochemical impedance spectroscopy was used to investigate the resistance during the reaction. The electric double-layer was found over the electrode surface when different amine solutions were used as the electrolyte. The spatial structure of ammonium cations and carbamate plays a key role in the FE of CO in this process.

CO2 capture using functionalized MIL-101(Cr) metal–organic frameworks: Functionality nanoarchitectonics of nanospace for CO2 adsorption

In this study, we investigated the effect of functional groups of metal–organic frameworks (MOFs) on CO2 adsorption at low pressure through experimental and computational approaches. We compared the performance of −SO3H, –NO2, aryl –NH2, and alkyl –NH2 groups (in similar molar quantities) in CO2 adsorption under the same conditions. The adsorption efficiency followed in the order: alkyl –NH2 > -SO3H>aryl –NH2 > –NO2 because of the different adsorption mechanisms over the groups. The main mechanism over alkyl –NH2 was the formation of ammonium carbamate via the carbamic acid formation. The adsorption mechanism over −SO3H and aryl –NH2 groups was Lewis acid-base and H-bonding interactions, while that over –NO2 group was solely Lewis acid-base interaction. The alkyl amine exhibited the best performance (in adsorption capacity, selectivity, and adsorption heat) due to its ability to form carbamate readily. On the contrary, aryl amine demonstrated lower performance than −SO3H groups, attributed to their low capability to form carbamate. These findings underscore the importance of amine type in CO2 adsorption, highlighting that aryl amines, different from alkyl amines, perform worse than other functional groups, such as −SO3H.

Corrosion and Enhanced Hydrogen Evolution in Electrochemical Reduction of Ammonium Carbamate on Transition Metal Surfaces.

Experiments and theory are combined to search for catalyst activity and stability descriptors for the direct reactive capture and conversion (RCC) of CO2 in ammonia capture solutions using Cu, Ag, Au, Sn, and Ti electrodes. Two major phenomena emerge in RCC that are not predominant in the electrochemical CO2 reduction (CO2R) reaction, namely, the rapid corrosion and restructuring of the catalyst in the presence of the CO2-ammonia adducts and the promotion of the competing hydrogen evolution reaction (HER). The prevalence of HER in RCC is correlated to the electrostatic attraction of the protonated amine to the electrode and the repulsion of the captured CO2, using the potential of zero charge (PZC). The stability of catalysts under RCC conditions is a function of the applied potential and cannot be readily predicted using binding energy descriptors commonly used in the prediction of CO2R activity. A direct correlation between calculated binding energies of CO2R intermediates, atomic oxygen, hydrogen, and ammonia and the activity and stability of transition metals for RCC cannot be found, highlighting the need for descriptors beyond those known for CO2R.

Oxalic acid as a dual C1 surrogate for heterogeneous palladium-catalyzed tandem four-component quinazolinone synthesis.

Herein, a heterogeneous Pd/C-catalyzed direct one-step four-component double carbonylative approach for cascade synthesis of 2-aryl quinazolinones has been reported for the first time starting from 2-iodoaniline derivatives and aryl iodides. The given reaction involves the simultaneous implementation of two different gaseous surrogates i.e., ammonium carbamate as an NH3 precursor and oxalic acid as a bi-functional reagent acting as a CO as well as a C-atom surrogate under ligand-free conditions.

Switching between Nonisoenergetic Dynamic Covalent Reactions Using Host-Guest Chemistry.

CO2 reacts with simple amines in the presence of water to generate dynamic combinatorial libraries of majority (i.e., ammonium carbamates) and minority (i.e., ammonium carbonates) nonisoenergetic covalent adducts. Over the past two decades, our laboratory has reported on a new class of cavitands, namely, dyn[n]arenes, from which a polyanionic macrocycle is a highly efficient receptor for linear polyammoniums that forms [2]pseudorotaxanes in water at neutral pH. Herein, we demonstrate that the formation of [2]pseudorotaxanes shifts the equilibrium of CO2 capture by polyamines in water toward the quasi-exclusive formation of carbonate adducts, providing the first example of a switch between two competitive and reversible covalent processes triggered by host-guest interactions. In addition, this supramolecular approach to CO2 capture exhibits enhanced capture efficiency by increasing the state of protonation of complexed vs uncomplexed polyamines. Altogether, we report here that a templating approach can divert the outcome of two reversible covalent chemistries involving nucleophilic additions and acid-base reactions, challenging therefore the common knowledge that noncovalent and covalent bonds operate in separate energy frames.

The Biocatalytic Potential of Aromatic Ammonia-Lyase from Loktanella atrilutea.

Characterization of the aromatic ammonia-lyase from Loktanella atrilutea (LaAAL) revealed reduced activity towards canonical AAL substrates: l-Phe, l-Tyr, and l-His, contrasted by its pronounced efficiency towards 3,4-dimethoxy-l-phenylalanine. Assessing the optimal conditions, LaAAL exhibited maximal activity at pH 9.5 in the ammonia elimination reaction route, distinct from the typical pH ranges of most PALs and TALs. Within the exploration of the ammonia source for the opposite, synthetically valuable ammonia addition reaction, the stability of LaAAL exhibited a positive correlation with the ammonia concentration, with the highest stability in 4 M ammonium carbamate of unadjusted pH of ~9.5. While the enzyme activity increased with rising temperatures yet, the highest operational stability and highest stationary conversions of LaAAL were observed at 30 °C. The substrate scope analysis highlighted the catalytic adaptability of LaAAL in the hydroamination of diverse cinnamic acids, especially of meta-substituted and di-/multi-substituted analogues, with structural modelling exposing steric clashes between the substrates' ortho-substituents and catalytic site residues. LaAAL showed a predilection for ammonia elimination, while classifying as a tyrosine ammonia-lyase (TAL) among the natural AAL classes. However, its distinctive attributes, such as genomic context, unique substrate specificity and catalytic fingerprint, suggest a potential natural role beyond those of known AAL classes.

Evaluation of a novel fertilizer-drawn forward osmosis and membrane contactor hybrid system for CO2 capture using ammonia-rich wastewater

Chemical absorption is widely employed to capture carbon dioxide (CO2) for addressing climate change. While monoethanolamine (MEA) currently dominates as an absorption solvent, utilizing ammonia-rich wastewater offers advantages such as reduced costs, high absorption capacity, and the generation of ammonium carbamate. This study proposes an innovative fertilizer-drawn forward osmosis (FDFO)-membrane contactor (MC) hybrid system for economically and sustainably mitigating CO2 emissions using ammonia-rich wastewater. First, ammonia-lean synthetic wastewater was concentrated through an FDFO system, using three fertilizers (KCl, monoammonium phosphate, and diammonium phosphate) as draw solutions. While KCl achieved a 45% ammonia dilution, diammonium phosphate yielded the highest concentration approximately 49%. Also, MCs were assessed for CO2 absorption under various operational conditions. Increased liquid concentration and flow rates improved CO2 capture efficiency, whereas higher CO2 flow rates and concentrations resulted in an adverse effect. Furthermore, a simulation study of a hybrid FDFO-MC system was conducted to evaluate the feasibility and potential of the system. The results indicated that the FDFO-MC hybrid system has the potential to efficiently remove CO2 if sufficient concentration and flow rate of ammonia-rich solution was secured at the FDFO outlet. This innovation addresses CO2 emissions and wastewater challenges, adhering to circular economy principles.

Low waste and low-energy consumption automation renovation of anhydrous dyeing system using anhydrous washing

Supercritical carbon dioxide, ethanol, and dimethyl sulfoxide mixed medium enable cotton fabric anhydrous dyeing, reducing energy consumption, simplifying color matching, improving levelness and color depth, and enabling an expanded range of available reactive dyes. However, residual alkalis, ammonium carbamate, and unfixed reactive dyes remain on cotton fabric, necessitating further treatment to satisfy the requirements for ecological textiles. This study used and recycled ethanol and dimethyl sulfoxide to effectively eliminate residual alkalis, ammonium carbamate, and unfixed reactive dyes from dyed cotton fabric and achieved the automation renovation of the corresponding anhydrous dyeing system to minimize waste discharge. The results show that residual alkalis and ammonium carbamate could be eliminated by washing with an ethanol solution containing citric acid, and the unfixed reactive dyes could be eliminated by washing with dimethyl sulfoxide. After being washed with ethanol and dimethyl sulfoxide, the dyed cotton fabric exhibits a grade 4 washing and rubbing fastness or higher and a pH value of 7, satisfying requirements for ecological textiles. The renovated automatic anhydrous dyeing system could achieve an E factor of 0.037, while its theoretical energy consumption of solvent recycling was 0, according to the Green Chemistry Principles 1 (prevention) and 6 (design for energy efficiency). It indicates that the automatic anhydrous dyeing system aligns more closely with the requirements outlined in the United Nations Sustainable Development Goal 12 (responsible production and consumption) than previously published dyeing systems.

Effect of ammonium carbamate on catalytic sulfidation and flotation of azurite

This study aimed to investigate the effectiveness of catalytic sulfidation using ammonium carbamate and sodium sulfide to achieve satisfactory flotation recovery rates of azurite. The recovery rate of 82.51 % azurite was achieved through catalytic sulfidation. The Cu(II) and S2− species on the pure azurite surface were reduced and oxidized to Cu(I) species, Sn2− or S2− species, respectively. The analyses revealed that the rougher the azurite surface, the higher the atomic concentration of S and the more CuS2 species formed, and the more xanthate adsorption led to the formation of hydrophobic surfaces, promoting the flotation of azurite. The dissociative adsorption of H2O molecules on the (011) surface of azurite hindered further adsorption of HS− species on the (011) surface of azurite. The adsorption energy of HS− species on the (011) surface of azurite was more negative with NH3, indicating that the NH3 enhanced the adsorption of HS− species. In addition, the chemical bond strength of Cu-S formed through catalytic sulfidation of azurite was stronger than the chemical bond strength of Cu-S formed through direct sulfidation. The enhancement between S and Cu bonds greatly improved the stability of sulfide layers after catalytic sulfidation.

Two-dimensional interfacial enhanced CO2 adsorption performance of porous organic amine solids: Structure-activity relationships and DFT calculations

The utilization of inexpensive and efficient amine-functionalized adsorbents has become a research hotspot in post-combustion capture technology. Meanwhile, the structure of the support and the selection of organic amines are the primary considerations affecting the CO2 adsorption performance. Herein, the novel solid amine adsorbent materials with amine-support interfacial effect were successfully synthesized in this study by loading four organic amines (TETA, TEPA, PEHA, and PEI) onto expanded vermiculite (EVMT) support with the layered structure. The results indicated that EVMT-50TETA exhibited superior CO2 adsorption capacity (132.5 mg/g) along with effective regeneration capability. This was attributed to the unique layered structure of EVMT that facilitates the dispersion of TETA on its surface or between layers as well as the formation of hydrogen bonds between surface functional groups (–OH) and amines to enhance the amine-support interfacial interaction. Furthermore, the minimal volume expansion of TETA during CO2 adsorption enables improved diffusion of CO2 in channels and enhanced accessibility to active sites. DFT calculations show higher binding energies and faster CO2 adsorption-diffusion rates between TETA and EVMT support. In situ DRIFTS experiments revealed that the process of CO2 adsorption followed the zwitterion mechanism, in which the zwitterion can be reversibly deprotonated to form ammonium carbamate and carbamic acid. This study provides comprehensive insights into the supports and amines interfacial effects through systematic investigation, offering both simplified synthesis strategies and profound theoretical support for studying solid amine adsorbents.

High-Capacity, Cooperative CO2 Capture in a Diamine-Appended Metal-Organic Framework through a Combined Chemisorptive and Physisorptive Mechanism.

Diamine-appended Mg2(dobpdc) (dobpdc4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) metal-organic frameworks are promising candidates for carbon capture that exhibit exceptional selectivities and high capacities for CO2. To date, CO2 uptake in these materials has been shown to occur predominantly via a chemisorption mechanism involving CO2 insertion at the amine-appended metal sites, a mechanism that limits the capacity of the material to ∼1 equiv of CO2 per diamine. Herein, we report a new framework, pip2-Mg2(dobpdc) (pip2 = 1-(2-aminoethyl)piperidine), that exhibits two-step CO2 uptake and achieves an unusually high CO2 capacity approaching 1.5 CO2 per diamine at saturation. Analysis of variable-pressure CO2 uptake in the material using solid-state nuclear magnetic resonance (NMR) spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reveals that pip2-Mg2(dobpdc) captures CO2 via an unprecedented mechanism involving the initial insertion of CO2 to form ammonium carbamate chains at half of the sites in the material, followed by tandem cooperative chemisorption and physisorption. Powder X-ray diffraction analysis, supported by van der Waals-corrected density functional theory, reveals that physisorbed CO2 occupies a pocket formed by adjacent ammonium carbamate chains and the linker. Based on breakthrough and extended cycling experiments, pip2-Mg2(dobpdc) exhibits exceptional performance for CO2 capture under conditions relevant to the separation of CO2 from landfill gas. More broadly, these results highlight new opportunities for the fundamental design of diamine-Mg2(dobpdc) materials with even higher capacities than those predicted based on CO2 chemisorption alone.

Laboratory Analogs of Thermally Processed Ices Containing H2O, N2, NH3, CO2, and C2H3N Relevant to Astrophysical Environments

Introduction: Laboratory simulations can benefit ground- and space-based observations of icy bodies in outer space. It is well-known that NH3 and CO2 can interact, forming ammonium carbamate (CH6N2O2). Method: This study examines NH3 and CO2 in thermally processed H2O-rich ices in the laboratory via mid-infrared absorption spectroscopy. In particular, the presence of CO2 in NH3- ice mixtures thermally annealed at 150 K for more than four hours in systematic experiments suggested that ammonium carbamate could potentially trap volatiles within the ice matrix. Result: Additional studies with acetonitrile (C2H3N) in ice mixtures containing H2O, CO2, and NH3 were also performed. Absorption peak position changes were recorded when the temperature was slowly increased (≤ 5K/min) and also annealed at temperatures up to 150 K. Conclusion: These studies will hopefully be useful in interpreting pre-biotic chemistry in the Solar System.

Carbon dioxide capture using diaminoalkane-grafted MIL-101(Cr)s: Critical role of geometric configuration of loaded amines

Preventing the increase of CO2 content in the atmosphere is crucial to mitigating climate change. In this study, we investigated the adsorption of CO2 using isostructural Cr-based MOFs, MIL-101 and MIL-100, after grafting diaminoalkanes with various chain lengths to determine the effect of the geometric configuration of the amines and to develop a competitive adsorbent. The performance of CO2 adsorption (e.g., adsorption capacity, selectivity, and adsorption heat) over MIL-101 increased as the size of diaminoalkanes increased, topped with 1,4-butanediamine, and declined with longer diaminoalkanes. The favorable contribution of grafted 1,4-butanediamine in increasing the performances in CO2 adsorption could be explained by the adequate size of the amines for the optimized configuration in the pore window of the MIL-101. However, interestingly, none of the MIL-100s grafted with diaminoalkanes showed a similar positive effect probably because of the smaller pore window of MIL-100 than that of MIL-101. To the best of our knowledge, this is the first study to demonstrate the importance of geometric configuration (or, the chain length of amines) in amine-grafted MOFs for the CO2 adsorption that follows the general mechanism that requires interactions between two uncoordinated amines for the formation of ammonium carbamates. Moreover, one of the modified MIL-101 grafted with 1,4-butanediamine exhibited remarkable performance in CO2 adsorption with 4.0 times the adsorption capacity of CO2 at 15 kPa and 20.6 times CO2/N2 selectivity (based on ideal adsorbed solution theory, at 100 kPa) compared to the virgin MIL-101.

Thermal Synthesis of Carbamic Acid and Its Dimer in Interstellar Ices: A Reservoir of Interstellar Amino Acids.

Reactions in interstellar ices are shown to be capable of producing key prebiotic molecules without energetic radiation that are necessary for the origins of life. When present in interstellar ices, carbamic acid (H2NCOOH) can serve as a condensed-phase source of the molecular building blocks for more complex proteinogenic amino acids. Here, Fourier transform infrared spectroscopy during heating of analogue interstellar ices composed of carbon dioxide and ammonia identifies the lower limit for thermal synthesis to be 62 ± 3 K for carbamic acid and 39 ± 4 K for its salt ammonium carbamate ([H2NCOO-][NH4+]). While solvation increases the rates of formation and decomposition of carbamic acid in ice, the absence of solvent effects after sublimation results in a significant barrier to dissociation and a stable gas-phase molecule. Photoionization reflectron time-of-flight mass spectrometry permits an unprecedented degree of sensitivity toward gaseous carbamic acid and demonstrates sublimation of carbamic acid from decomposition of ammonium carbamate and again at higher temperatures from carbamic acid dimers. Since the dimer is observed at temperatures up to 290 K, similar to the environment of a protoplanetary disk, this dimer is a promising reservoir of amino acids during the formation of stars and planets.

Amino-functionalized silicones processed as porous dual covalent/supramolecular networks for pressure sensing

Polysiloxanes, pendant functionalized with aminopropyl groups and having silanol chain ends, were used as the frameworks to obtain porous networks, in the presence of certain additions. The porosity was achieved by the thermal decomposition gases of ammonium bicarbonate as chemical blowing agent (CBA), in the presence of acetic acid. The latter promotes at the same time covalent cross-linking of the polymer by condensing the silanol chain ends with tetraethoxysilane, thus eliminating the need to add an organometallic catalyst, often used for this purpose. In the presence of CO2 generated during the CBA decomposition, thermally reversible supramolecular ammonium carbamate bridges are also formed between the chains, thus leading to dual covalent/supramolecular cross-linked silicone networks, and increasing the degree of crosslinking. In addition, the presence of the polar groups leads to a rise in the dielectric permittivity of the porous and flexible materials, resulting in a significant increase in the electrical output signal when these are subjected to compression. The materials exhibited stable capacitance variation with a response sensitivity of about 0.01 kPa−1, in the pressure range 0–50 kPa, making them suitable for capacitive pressure sensors.

Enhanced solar light photocatalytic activity of TiO2 modified with ammonium carbamate for the removal of ketoprofen from water

This study was focused on the investigation on the influence of modification of TiO2 with ammonium carbamate on its physicochemical properties and photocatalytic activity under simulated solar light. A simple mechanochemical approach based on ball-milling combined with calcination was adapted to obtain novel C,N,S-modified TiO2-based materials. Ammonium carbamate was used as C and N source, while a crude TiO2 acquired from sulfate technology was applied as TiO2 and S precursor. The photoactivity of the prepared photocatalysts was examined towards ketoprofen decomposition under simulated solar light. Additionally, the most efficient photocatalysts were examined under the visible and UV light. The influence of the preparation conditions (rotation speed, ball-milling time, calcination temperature and ammonium carbamate dose) on the photoactivity of the photocatalysts was investigated for the first time. All novel photocatalysts revealed improved ketoprofen photodecomposition efficiency (67–72 %) compared to the TiO2 P25 (60 %), the crude TiO2 (29 %) and a synthesized referential photocatalyst (60 %). The highest photoactivity was achieved for the photocatalysts prepared through 1 h of ball-milling with the speed of 600 rpm and calcined at 600 °C. The ketoprofen decomposition efficiency was rising with the increasing TiO2:N weight ratio from 9:1 to 5:5 for all the investigated types of radiation.

Hormesis of glyphosate on ferulic acid metabolism and antifungal volatile production in rice root biocontrol endophyte Burkholderia cepacia LS-044

Glyphosate (GP, N-phosphonomethyl glycine) is one of the most popular organophosphate herbicides widely used in agricultural practices worldwide. There have been extensive reports on the biohazard attributes and hormetic impacts of GP on plant and animal systems. However, the effects of GP on plant growth-promoting microbes and its ecological relevance remain unknown. Here, we show that GP does exert a hormetic impact on Burkholderia cepacia LS-044, a rice (Oryza sativa ssp. japonica cv. Tainung 71) root endophytic isolate. We used increasing doses of ferulic acid (FA, 1–25 mM) and GP (0.5–5 mM) to test the growth and antifungal volatile production in LS-044 by electrochemical, liquid chromatographic, gas chromatographic and spectrophotometric means. GP treatment at a low dose (0.5 mM) increased FA utilization and significantly (P < 0.0001) enhanced antifungal volatile activity in LS-044. Although FA (1 mM) was rapidly utilized by LS-044, no chromatographically detectable utilization of GP was observed at tested doses (0.5–5 mM). LS-044 emitted predominant amounts of tropone in addition to moderate-to-minor amounts of diverse ketones and/or their derivatives (acetone, acetophenone, 2-butanone, 1-propanone, 1-(2-furanyl-ethanone, 1-phenyl-1-propanone and 1-(3-pyridinyl)-1-propanone), d-menthol, 2-methoxy-3-(1-methylethyl)-pyrazine, dimethyl disulfide, pyridine and ammonium carbamate when grown under GP supplement. GP hormesis on LS-044 induced phenotypic variations in O. sativa ssp. japonica cv. Tainan 11 as evident through seed germination assay. Genes involved in the transformation of FA, and a key gene encoding 5-enolpyruvylshikimate 3-phosphate synthase (EPSPS) with Gly-94 and Tyr-95 residues localized at active site most likely rendering EPSPS sensitivity to GP, were detected in LS-044. This is the first report on the GP hormesis influencing morphological and metabolic aspects including volatile emission in a biocontrol bacterium that could modulate rice plant phenotype.

Progress in Photochemical and Electrochemical C-N Bond Formation for Urea Synthesis.

ConspectusHere, we discuss recent advances and pressing challenges in achieving sustainable urea synthesis. Urea stands out as the most prevalent nitrogen-based fertilizer used across the globe, making up over 50% of all manufactured fertilizers. Historically, the Bosch-Meiser process has been the go-to chemical manufacturing method for urea production. This procedure, characterized by its high-temperature and high-pressure conditions, reacts ammonia with carbon dioxide to form ammonium carbamate. Subsequently, this ammonium carbamate undergoes dehydration, facilitated by heat, producing solid urea. A concerning aspect of this method is its dependency on fossil fuels, as nearly all the process heat comes from nonrenewable sources. Consequently, the Bosch-Meiser process leaves behind a considerable carbon footprint. Current estimates predict that unchecked, carbon emissions from urea production alone might skyrocket, reaching a staggering 286 MtCO2,eq/yr by 2050. Such projections paint a clear picture regarding the necessity for more eco-friendly, sustainable urea production methods. Recently, the scientific community has shown growing interest in forming C-N bonds using alternative methods. Shifting toward photochemical or electrochemical processes, as opposed to traditional thermal-based processes, promises the potential for complete electrification of urea synthesis. This shift toward process electrification is not just an incremental change; it represents a groundbreaking advancement, the first of many steps, toward achieving deep decarbonization in the chemical manufacturing sector. Since the turn of 2020, there has been a surge in research focusing on photochemical and electrochemical urea synthesis. These methods capitalize on co-reduction of carbon dioxide with nitrogenous reactants like NOx and N2. Despite the progress, there are significant challenges that hinder these processes from reaching their full potential. In this comprehensive review, we shed light on the advances made in electrified C-N bond formation. More importantly, we focus on the invaluable insights gathered over the years, especially concerning catalytic reaction mechanisms. We have dedicated a section to underline key focal areas for up-and-coming research, emphasizing catalyst, electrolyte, and reactor design. It is undeniable that catalyst design remains at the heart of the matter, as managing the co-reduction of two distinct reactants (CO2 and nitrogenous species) is complex. This process results in a myriad of intermediates, which must be adeptly managed to both maintain catalyst activity and avoid catalyst deactivation. Moreover, the electrolytes play a pivotal role, essentially dictating the creation of optimal microenvironments that drive reaction selectivity. Finally, reactor engineering stands out as crucial to ensure optimal mass transport for all involved reactants and subsequent products. We touch upon the broader environmental ramifications of urea production and bring to light potential obstacles for alternative synthesis routes. A notable mention is the urgency of accelerating the uptake and large-scale implementation of renewable energy sources.