Ammonia Production Research Articles

Review of AEM Electrolysis Research from the Perspective of Developing a Reliable Model

This review thoroughly examines recent progress, challenges, and future prospects in the field of alkaline exchange membrane (AEM) electrolysis. This emerging technology holds promise for eco-friendly hydrogen production. It blends the benefits of traditional alkaline and proton-exchange membrane technologies, enhancing affordability and operational efficiencies by utilizing non-precious metal catalysts and operating at reduced temperatures. This study discusses key developments in materials, electrode design, and performance enhancement techniques. It also highlights the strategic role of AEM electrolysis in meeting global energy transition targets, like achieving Net Zero Emissions by 2050. An in-depth exploration of the operational fundamentals of AEM water electrolysis is provided, noting the technology’s early stage development and the ongoing need for research in membrane-electrode assembly assessment, catalyst efficiency, and electrochemical ammonia production. Moreover, this review compiles results on different cell components, electrolyte types, and experimental approaches, providing insights into operational parameters critical to optimizing AEM performance. The conclusion emphasizes the necessity for continuous research and commercialization efforts to exploit AEM electrolysis’s full potential across diverse industries.

Optimisation of Ammonia Production and Supply Chain from Sugarcane Ethanol and Biomethane: A Robust Mixed-Integer Linear Programming Approach

Optimisation of Ammonia Production and Supply Chain from Sugarcane Ethanol and Biomethane: A Robust Mixed-Integer Linear Programming Approach

Deciphering Hyperammonia-Producing Bacteria (HAB) in the Rumen of Water Buffaloes (Bubalus bubalis) and Their Inhibition through Plant Extracts and Essential Oils

Hyperammonia-producing bacteria (HAB) are a class of microbes present in the stomach of ruminants, responsible for the rapid rate of ammonia production from protein degradation beyond the capacity of these animals for their utilization. Thus, ruminant nutritionists are interested in decreasing ruminal protein degradation and ammonia genesis by focusing on controlling the activity of HAB. The investigations of the present study were carried out to determine predominant hyperammonia-producing bacteria in the rumen of buffaloes, their isolation and characterization, as well as the inhibition of these isolates with various sources of plant secondary compounds (tannins, saponins, and essential oils). Studies employing high-throughput sequencing of amplicons of the 16S rRNA gene from genomic DNA recovered from enrichment culture of HAB of buffalo rumina indicated that, at the phylum level, Proteobacteria (61.1 to 68.2%) was the most predominant HAB. Acidaminococcus was most predominant among the identified genera. In vitro experiments were conducted with enrichment culture of buffalo rumen contents incubated with different types of feed additives such as essential oils (eucalyptus oil, lemon grass oil, and clove oil) and extracts of plants (Sapindus mukorossi fruits and Ficus bengalensis leaves), each at graded dose levels. The reduction in ammonia production by clove and lemon grass oils was evident due to the presence of major bioactive compounds, especially eugenol and limonene, which have strong antimicrobial activity. However, clove oil and Indian soapberry/reetha (Sapindus mukorossi) fruit were found to be promising and effective in reducing the growth, protease production, and ammonia production of HAB culture.

Rapid Fabrication of N-, Cu-, and Co-Doped Electrodes with Strong Electronic Coupling by Cold Plasma for Electrocatalytic Reduction of Nitrate to Ammonia.

Electrochemical NOx- reduction (NOxRR) is a sustainable technology for ammonia synthesis. The development of a simple, fast, and economical catalytic electrode preparation technique is crucial for large-scale ammonia synthesis. Herein, we propose a plate-to-plate DBD plasma strategy to synthesize the catalytic electrodes M-N/CP (M = Cu, Co, Ni, CuCo, and CuNi), achieving in suit codoping of N and bimetals on carbon paper (CP) at room temperature within 3 h. N-doping improves the metal loading and the NOxRR performance by forming N-M bonds. The electronic coupling and synergistic effect of Cu and Co sites facilitate the relay conversion of NO3- to NO2- to NH3. Notably, the NO3- removal efficiency of CuCo-N/CP reaches 82%, with NH3 yield rate of 346 μg h-1 cm-2, and the faradaic efficiency is as high as 86% at -0.58 V vs RHE, which remains competitive in terms of NOxRR performance. Importantly, wet flue gas denitrification and desulfurization coupled with electrocatalytic reduction can convert NOx and SO2 to (NH4)2SO4, Additionally, the maneuverability of plasma technology offers the potential for batch preparation of CuCo-N/CP electrodes for electrochemically driven wet denitrification wastewater valorization.

Sustainable ammonia and amines from chitin

Efforts are underway to explore alternative methods to the Haber-Bosch process for sustainable ammonia production, while the potential for ammonia extraction from natural nitrogenous biomass is under-exploited. Here, a synergistic catalytic strategy involving acid and modified Ru-based catalysts is communicated for the direct production of amines and ammonia from chitin. Phosphoric acid promotes the cleavage of ether bonds in biomass polymers and also serves to protect amino groups from being removed. Selective hydrogenation, deoxygenation, and amination can be achieved by controllably adjusting the ratio of Ru0/Run+. The utilization of nitrogen atoms in chitin can reach up to 95 % (21 % amines, 74 % ammonium), and the catalytic process is applicable to waste shrimp shells. This study demonstrates the possibility of efficient production of nitrogen-containing compounds from abundant biopolymers.

Designing C9N10 Anchored Single Mo Atom as an Efficient Electrocatalyst for Nitrogen Fixation.

Electrochemical nitrogen reduction reaction (NRR) is a promising route for realizing green and sustainable ammonia synthesis under ambient conditions. However, one of the major challenges of currently available Single-atom catalysts (SACs) is poor catalytic activity and low catalytic selectivity, which is far away from the requirements of industrial applications. Herein, first-principle calculations within the density functional theory were performed to evaluate the feasibility of a single Mo atom anchored on a g-C9N10 monolayer (Mo@g-C9N10) as NRR electrocatalysts. The results demonstrated that the gas phase N2 molecule can be sufficiently activated on Mo@g-C9N10, and N2 reduction dominantly occurs on the active Mo atom via the preferred enzymatic mechanism, with a low limiting potential of -0.48 V. In addition, Mo@g-C9N10 possesses a good prohibition ability for the competitive hydrogen evolution reaction. More impressively, good electronic conductivity and high electron transport efficiency endow Mo SACs with excellent activity for electrocatalytic N2 reduction. This theoretical research not only accelerates the development of NRR electrocatalysts but also increases our insights into optimizing the catalytic performance of SACs.

Efficient electrocatalytic reduction of nitric oxide (NO) to ammonia (NH3) on metal-free B4@g-C3N4 nanosheet

The combustion of fossil fuels releases substantial amounts of nitric oxide (NO), posing serious environmental and health risks. Addressing NO pollution effectively is, therefore, a pressing need. Conversion of NO into valuable chemicals is an appealing strategy with dual benefits, including waste utilization and sustainable energy transformation. In this study, we investigate the metal-free electrocatalytic reduction of NO (NORR) to NH3 on a B4 atomic cluster supported by a g-C3N4 nanosheet (B4@g-C3N4) using density functional theory (DFT). Our findings reveal that NO is efficiently activated on the B4@g-C3N4 catalyst, favoring side-on and N end-on adsorption configurations. Significant electron transfer and strong adsorption energies confirm the chemisorption of NO. The NORR exhibits an impressively low limiting potential (UL) of −0.29 V in the gas phase, which decreases further under solvent effects and varying charge states (−2e-, −1e-, +1e-, +2e-). Additionally, the high negative UL values for competing side reactions such as H2 (−0.42 V), N2 (−0.29 V), and N2O (−0.72 V) underscore the selectivity of B4@g-C3N4 for ammonia synthesis. These results highlight the promising potential of B4@g-C3N4 nanosheets for eco-friendly ammonia production from NO, providing a theoretical basis for future experimental efforts to combat NO pollution.

Operational long-term management of a salt cavern for industry targeted green H2 production

Hydrogen and its derivatives such as ammonia are increasingly important for reducing carbon emissions in sectors with limited alternatives. Large production systems are generally preferred to reduce costs and for those, advanced management is a cornerstone to the project economic viability. The present work explores the development of an Energy Management System for an industrial low-emission ammonia production platform. The latter is connected to the electrical grid and consists of 1.5 GW of renewable production units, around 500 MW of electrolyzers and storage facilities including especially a salt cavern for H2 storage. The long-term management of the salt cavern is decisive to enhance the profitability while satisfying industry related constraints such as the carbon content of the produced H2. The literature lacks in addressing both aspects simultaneously. Methodological approaches to tackle the long-term management and industrial constraints are proposed and compared. For the considered platform, it is shown that a strategy based on precalculated cost functions in the long term horizon allows relative gains of 2.5% with respect to a state-of-the-art short term management leading to an annual cost saving of approximately $6.2 million in the platform operational expenses. This translates to a reduction of the gap between the state-of-the-art and the optimal a posteriori solution by about 82%.

Genetic Diversity and Functional Potential of Streptomyces spp. Isolated from Pachmarhi Biosphere Reserve, India.

Streptomyces is a diverse genus, well known for producing a wide array of metabolites that have significant industrial utilization. The present study investigates the genetic and functional diversity of Streptomyces spp. isolated from the Pachmarhi Biosphere Reserve (PBR), India, an unexplored site. The 16S rRNA gene sequencing and analysis revealed 96 isolates belonging to 40 different species indicating a substantial phylogenetic diversity. The strains were clustered into two groups: a major cluster with 94 strains and a small cluster with two strains. BOX- PCR analyses revealed an incredible genetic diversity existing among the strains of Streptomyces spp. in PBR. The analyses revealed the intra-species diversity and inter-species closeness within the genus Streptomyces in the study area. Qualitative screening for enzyme production has shown that 53, 42, 41, 11, and 54 strains tested positive for CMCase, xylanase, amylase, pectinase, and β-glucosidase, respectively. Additionally, 54 strains tested positive for PHB production. The strains were assayed quantitatively for the production of CMCase, xylanase, amylase, and pectinase. Streptomyces sp. MP9-2, Streptomyces sp. MP10-11, Streptomyces sp. MP10-18, and Streptomyces sp. MP10-6 recorded maximum CMCase (0.604 U/mL), xylanase (0.553 U/mL), amylase (1.714 U/mL), and pectinase (13.15 U/mL) activities, respectively. Furthermore, several strains demonstrated plant growth-promoting traits, viz. zinc and phosphate solubilization and production of ammonia, HCN (hydrogen cyanide), and IAA (Indole acetic acid), and nitrogen fixation. Fifty strains showed antifungal activity against Fusarium oxysporum f. sp. lycopersici with inhibitions ranging from 7.5 to 47.5%. Current findings underscore the ecological and biotechnological significance of Streptomyces spp. in the unexplored habitat of PBR.

Electrocatalytic Ammonia Production from Nitrogen with Enhanced Faradaic Efficiency Using Nanostructured Bi2MoO6

Electrocatalytic Ammonia Production from Nitrogen with Enhanced Faradaic Efficiency Using Nanostructured Bi₂MoO₆

Chidambar Kulkarni.

"A turning point in my career was exploring the molecular design of responsive polymers and macromolecular materials as a postdoctoral scholar… My group has fun by laughing, both in lab and group meeting, as well going on fun outings like group cookouts on the beach…" Find out more about Benjamin McDonald in his Introducing… Profile.

Reduction of N2 to NH3 using FeP(101)/TiO2 catalysts: A First-principles study

The electrochemical nitrogen reduction reaction offers an eco-friendly and sustainable way for synthesizing ammonia at room temperature, in contrast to the energy-intensive Haber-Bosch process. In this study, we demonstrate that FeP (101) is stabilized by anatase TiO2(101), resulting in the formation of a FeP/TiO2 composite. This composite shows promising potential as a catalyst for N2 electroreduction. All hydrogenation reactions are feasible and occur spontaneously, with the ∗N2-∗N2H step serving as the potential determining step (PDS) with a value of 0.59 V. In comparison to the Ru (0001) surface (1.08 V), which exhibits superior catalytic activity in nitrogen reduction reactions (NRR), the obtained value is significantly lower. FeP/TiO2 exhibits ∼100% selectivity towards ammonia synthesis as compared to the competitive hydrogen evolution process (HER). This study demonstrates that the correlation between N2 activation and the electronic structure will aid in the fundamental comprehension, design, and alteration of NRR catalysts.

Considering Embodied Greenhouse Emissions of Nuclear and Renewable Power Plants for Electrolytic Hydrogen and Its Use for Synthetic Ammonia, Methanol, Fischer-Tropsch Fuel Production.

Recent concerns surrounding climate change and the contribution of fossil fuels to greenhouse gas (GHG) emissions have sparked interest and advancements in renewable energy sources including wind, solar, and hydroelectricity. These energy sources, often referred to as "clean energy", generate no operational onsite GHG emissions. They also offer the potential for clean hydrogen production through water electrolysis, presenting a viable solution to create an environmentally friendly alternative energy carrier with the potential to decarbonize industrial processes reliant on hydrogen. To conduct a full life cycle analysis, it is crucial to account for the embodied emissions associated with renewable and nuclear power generation plants as they can significantly impact the GHG emissions linked to hydrogen production and its derived products. In this work, we conducted a comprehensive analysis of the embodied emissions associated with solar photovoltaic (PV), wind, hydro, and nuclear electricity. We investigated the implications of including plant-embodied emissions in the overall emission estimates of electrolysis hydrogen production and subsequently on the production of synthetic ammonia, methanol, and Fischer-Tropsch (FT) fuels. Results show that average embodied GHG emissions of solar PV, wind, hydro, and nuclear electricity generation in the United States (U.S.) were estimated to be 37, 9.8, 7.2, and 0.3 g CO2 e/kWh, respectively. Life cycle GHG emissions of electrolytic hydrogen produced from solar PV, wind, and hydroelectricity were estimated as 2.1, 0.6, and 0.4 kg of CO2 e/kg of H2, respectively, in contrast to the zero-emissions often used when the embodied emissions in their construction were excluded. Average life cycle emission estimates (CO2 e/kg) of synthetic ammonia, methanol, and FT-fuel from solar PV electricity are increased by 5.5, 16, and 49 times, respectively, compared to the case when embodied emissions are excluded. This change also depends on the local irradiance for solar power, which can result in a further increase of GHG emissions by 35-41% in areas of low irradiance or reduce GHG emissions by 21-25% in areas with higher irradiance.

A study on the potential of endophytic bacteria to promote plant growth: uses in agriculture and future directions

The escalating demand for chemical-free fertilizers in agriculture stems from the adverse impacts associated with chemical fertilizers on both human and animal health, as well as environmental pollution. To address this concern, plant-based microorganisms emerge as a promising solution for the development of environmentally sustainable biofertilizers. Among these microorganisms, endophytic bacteria, residing within plant tissues without causing harm to the host plant, exhibit exceptional attributes conducive to plant growth promotion. Notably, these bacteria demonstrate the production of phytohormones, ammonia, phosphate solubilization, and nitrogen fixation capabilities. Additionally, endophytic bacteria showcase the synthesis of hydrolytic enzymes, the production of siderophores, and antimicrobial activity against pathogens. Such characteristics contribute significantly to the robust growth and development of host plants, fostering tolerance to environmental stresses. This manuscript aims to comprehensively review the plant growth promotion activities of endophytic bacteria, elucidating their diversity and isolation from various plants. Furthermore, it explores the potential future directions in this burgeoning field of research, envisioning the development of endophytic bacterial strains capable of replacing traditional chemical fertilizers. Future research endeavors hold the promise of uncovering novel and effective endophytic bacterial strains, heralding a sustainable paradigm shift in the realm of agricultural fertilization.

Sub‐Nanometer‐Scale Cu9S5 Enables Efficiently Electrochemical Nitrate Reduction to Ammonia

AbstractThe sub‐nanometer is a key feature size in materials science. Unlike single‐atom and nanomaterials, size effects and inter‐component cooperative actions in sub‐nanomaterials will effective on its performance is more significant. Here, 0.95 nm ordered arrangement Cu9S5 sub‐nanowires (Cu9S5 SNWs) are synthesized through the co‐assembly effect of inorganic nuclei (Cu9S5) and clusters (phosphotungstic acid‐PTA), achieving a significant increase in the specific surface area of the sample and ≈100% atomic exposure rate, which is the key to its high catalytic activity. PTA clusters not only act as a “charge transfer station” to accelerate the inter‐component electron transfer process, but also facilitate the dissociation of water and provide more hydrogen protons, thus dramatically facilitating the electrocatalytic process. The experimental results show that the Cu9S5 SNWs exhibited excellent nitrate reduction reaction (NO3−RR) properties. The Faraday efficiency (FE) of NO3−RR is 90.4% at the optimum potential −0.3 VRHE (reversible hydrogen electrode) and the ammonia production is as high as 0.37 mmol h−1 cm−2, which is superior to most reported electrocatalysts. In addition, the Zn‐NO3− liquid‐flow battery devices assembled using Cu9S5 SNWs as electrode materials show excellent application results. This work provides a reference for the design of highly efficient sub‐nanoscale NO3−RR electrocatalysts.

DEVELOPMENT OF AN ENERGY-SAVING TECHNOLOGY FOR THE PRODUCTION OF SYNTHETIC METHANE FROM CARBON DIOXIDE. 1. RESEARCH OF KINETICS AND MACRO-KINETICS OF THE SABATIER REACTION ON MODIFICATIONS OF THE SERIAL NI/Α-AL2O3 CATALYST GIAP-3-6N

This study presents the results of laboratory research of kinetics and mechanisms of heterogeneous catalytic reactions of hydrogenation of carbon dioxide to carbon monoxide and methane through the Sabatier reaction on modifications of the serial Ni/α-Al2O3 catalyst GIAP-3-6N manufactured in Ukraine. The research was carried out on a laboratory bench using a classic glass gradientless reactor with internal piston stirring, which provides kinetic equations at the level of physicochemical constants of the reactions under consideration. A detailed analysis and review of the literature in the areas of kinetic research of our interest was carried out. A detailed comparison of the kinetic parameters obtained by us for the powder (kinetic) form of contact with a nickel content of 7.5 % (NiO = 7.5 %) with a similar and one of the best foreign analogs containing nickel, Katalco 57-4 (NiO = 15−18 %), produced by the British chemical and metallurgical company Johnson Matthey, was performed. The results of the research confirmed almost equal parameters of the kinetic activity of the compared catalysts in the reactions of hydrogenation of carbon dioxide with hydrogen, including the «Sabatier» reaction, which made it possible to propose a similar mechanism of the processes, calculate the reaction rate constants and their activation energy, propose (determine) kinetic equations for design of reactors and processes, both with the loading of a domestic catalyst and its replacement with a foreign analog. Kinetic equations will be used in the development of multi-ton synthesis gas plants for the production of methanol, ammonia, and synthetic methane, as well as carbon-free e-fuel for internal combustion engines that meet modern climate requirements. Bibl. 28, Fig. 4, Tab. 6.

Recent research trends in the rational design strategies of carbon-based electrocatalysts for electrochemical ammonia synthesis

Ammonia electrosynthesis is the most sustainable way to produce carbon-free hydrogen carriers, which would pave the way for the foreseen hydrogen economy and carbon neutralization as it has the potential to replace the conventional Haber-Bosch process. The electrocatalytic production of ammonia, which renewable energy resources could drive, reduces the carbon footprint contribution to fossil fuel consumption. Moreover, ammonia electrosynthesis also paves the way for recycling industrial/chemical wastewater and NO emissions. Hence, the advancement of electrocatalytic ammonia synthesis techniques is highly mandated for a greener future. This review consolidates the recent research trends associated with carbon-based electrocatalysts, which could elevate this viable technology with cost-effectiveness.

Electrocatalytic Nitrate Reduction for Brackish Groundwater Treatment: From Engineering Aspects to Implementation

In recent years, nitrate has emerged as a significant groundwater pollutant due to its potential ecotoxicity. In particular, nitrate contamination of brackish groundwater poses a serious threat to both ecosystems and human health and remains difficult to treat. A promising, sustainable, and environmentally friendly solution when biological treatments are not applicable is the conversion of nitrate to harmless nitrogen (N2) or ammonia (NH3) as a nutrient by electrocatalytic nitrate reduction (eNO3R) using solar photovoltaic energy. This review provides a comprehensive overview of the current advances in eNO3R for the production of nitrogen and ammonia. The discussion begins with fundamental concepts, including a detailed examination of the mechanisms and pathways involved, supported by Density Functional Theory (DFT) to elucidate specific aspects of ammonium and nitrogen formation during the process. Furthermore, the integration of artificial intelligence (AI) and machine learning (ML) offers promising advancements in enhancing the predictive power of DFT, accelerating the discovery and optimization of novel catalysts. In this review, we also explore various electrode preparation methods and emphasize the importance of in situ characterization techniques to investigate surface phenomena during the reaction process. The review highlights numerous examples of copper-based catalysts and analyses their feasibility and effectiveness in ammonia production. It also explores strategies for the conversion of nitrate to N2, focusing on nanoscale zerovalent iron as a selective material and the subsequent oxidation of the produced ammonia. Finally, this review addresses the implementation of the eNO3R process for the treatment of brackish groundwater, discussing various challenges and providing reasonable opinions on how to overcome these obstacles. By synthesizing current research and practical examples, this review highlights the potential of eNO3R as a viable solution to mitigate nitrate pollution and improve water quality.

The impact of offshore energy hub and hydrogen integration on the Faroe Island’s energy system

This study explores the integration of offshore wind energy and hydrogen production into the Faroe Islands’ energy system to support decarbonisation efforts, particularly focusing on the maritime sector. The EnergyPLAN model is used to simulate the impact of incorporating green hydrogen, produced via electrolysis, within a closed energy system. The study evaluates different configurations of hydrogen production and their feasibility focusing on electrolyser technologies and placement options (in-turbine, platform-based, and shoreline). The hydrogen produced is intended for ammonia production, replacing 11% of the fossil fuels used in maritime transport by 2030. Results indicate that integrating hydrogen with offshore wind energy can reduce fossil fuel reliance and carbon dioxide emissions. The in-turbine electrolyser setup offers the cost-effective placement option, while the platform setup is the most expensive. Among the three electrolyser technologies evaluated (alkaline, solid oxide and proton exchange membrane), the alkaline electrolyser results in the lowest overall system cost. The findings provide insights into the potential for renewable energy systems in a small island context and contribute to a broader understanding of green hydrogen’s role in energy transitions.

Conversion of Nitrate to Ammonia by Amidinothiourea-Coordinated Metal Molecular Electrocatalysts with d-π Conjugation.

The electrochemical reduction of nitrate to ammonia (NO3RR) provides a desired alternative of the traditional Haber-Bosch route for ammonia production, igniting a research boom in the development of electrocatalysts with high activity. Among them, molecular electrocatalysts hold considerable promise for the NO3RR, suppressing the competing hydrogen evolution reaction. However, the complicated synthesis procedure, usage of environmentally unfriendly organic solvents, and poor stability of Cu-based molecular electrocatalysts greatly limit their employment in NO3RR, and the development of desired Cu-based molecular catalysts remains challenging. Herein, a simple nonorganic solvent involving a one-step strategy was proposed to synthesize d-π-conjugated molecular electrocatalysts metal-amidinothiourea (M-ATU). Cu-ATU is composed of Cu coordinated with two S and two N atoms, whereas Ni-ATU is formed by Ni with four N atoms from two ATU ligands. Remarkably, Cu-ATU with a Cu-N2S2 coordination configuration exhibits superior NO3RR activity with a NH3 yield rate of 159.8 mg h-1 mgcat-1 (-1.54 V) and Faradaic efficiency of 91.7% (-1.34 V), outperforming previously reported molecular catalysts. Compared to Ni-ATU, Cu-ATU transfers more electrons to the *NO intermediate, effectively breaking the strong sp2 hybridization system and weakening the energy of N═O bonds. The increase in free energy of *NO reduced the energy barriers of the rate-determining step, facilitating the further hydrogenation process over Cu-ATU. Our work opened up a new horizon for exploring molecular electrocatalysts for nitrate activation and paved a way for the in-depth understanding of catalytic behaviors, aligning more closely with industrial demands.