Hydrogenation Process Research Articles

FeNiCu-based composite catalyst for hydrogen storage in MgH2

FeNiCu-based composite catalysis proves to be an effective strategy for enhancing the hydrogen storage performance of MgH2. Two catalysts, (Cu0.2Ni0.8) O/NiFe2O4 and FeNi3/Fe4Cu3, are successfully synthesized and doped into MgH2 to improve its hydrogen storage capability. Experimental results demonstrate that MgH2 + 5 wt% (Cu0.2Ni0.8)O/NiFe2O4 (MgH2 + 5 A) and MgH2 + 5 wt% FeNi3/Fe4Cu3 (MgH2 + 5B) composites desorption at 171 ℃ and 178 ℃, respectively, which is 100 ℃ lower than that of ball-milled MgH2. Under conditions of 150 ℃ and 3 MPa, MgH2 + 5 A can absorb 6.02 wt% H2 in just one minute. MgH2 + 5B, at 225/325 ℃, exhibits hydrogen absorption/desorption exceeding 7 wt% H2 for 1 h. The synergistic effect of in situ formed Mg2Ni and Fe positively impacts the hydrogen storage behavior of MgH2. The introduced interface offers numerous low-energy barrier H-diffusion channels, resulting in accelerated release and hydrogen absorption. Additionally, Cu4O3 dispersed on the surface of the matrix particles maintains its valence during the process of hydrogen absorption/desorption. This property can facilitate the conversion of Mg2Ni/Mg2NiH4 into a “hydrogen pump”. This study provides an experimental basis and new insights for designing highly efficient catalysts for Mg-based hydrogen storage materials.

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.

Hydrothermal Catalytic Transformations of Polymeric Wastes over Zeolite Catalysts Modified with Molybdenum and Tungsten

The article is devoted to the study of the adsorption properties and morphology of new composite catalysts based on acid-activated zeolite heulandite-clinoptilolite of the Kazakhstan Taizhuzgen deposit modified with molybdenum salts (NH4)MoO·4H2O and tungsten (NH4)5H5[H2(WO4)6]·H2O, for the process of thermocatalytic hydrogenation of plastic waste. The study of the developed catalyst by the method of adsorption nitrogen porometry demonstrated the presence of typical type IV isotherms, which indicated the formation of a porous adsorbent by multilayer nitrogen adsorption in the mesopores of the catalyst. The adsorption capacity of the structure formed by the catalyst based on zeolite modified with molybdenum and tungsten, due to the presence of predominantly mesoporous cavities, is able to selectively influence the process of hydrothermocatalytic processing of waste polymers based on polyethylene and polypropylene. The pore size distribution indicates the presence of mesopores and an insignificant number of micropores at low pressure. The catalyst samples were tested in the thermocatalytic hydrogenation reaction of polymer waste. Significant gas formation and predominant content of alkanes, isoalkanes, alkenes and aromatic hydrocarbons in liquid products are shown. It is obviously that the main contribution to the transformations made by mesoporous inclusions in the cavities of the zeolite under study formed during their treatment with molybdenum and tungsten salts.

Copper–nickel–MOF/nickel foam catalysts grown in situ for efficient electrochemical nitrate reduction to ammonia

Reducing nitrate (NO3−) in an aqueous solution to ammonia under ambient conditions can provide a green and sustainable NH3‐synthesis technology and mitigate global energy and pollution issues. In this work, a CuNi0.75–1,3,5‐benzenetricarboxylic acid/nickel foam (CuNi0.75–MOF/NF) catalyst grown in situ was prepared via a one‐pot method as an efficient cathode material for electrocatalytic nitrate reduction reaction (NO3RR). The CuNi0.75–MOF/NF catalyst exhibited excellent electrocatalytic NO3RR performance at −1.0 V versus a reversible hydrogen electrode, achieving an outstanding faradaic efficiency of 95.88 % and an NH3 yield of 51.78 mg h−1 cm−2. The 15N isotope labeling experiments confirmed that the sole source of N in the electrocatalytic NO3RR was the NO3− in the electrolyte. The reaction pathway for the electrocatalytic NO3RR was derived by in situ Fourier transform infrared spectroscopy and in situ differential electrochemical mass spectrometry. Density functional theory calculations revealed that the Ni element in the CuNi0.75–MOF/NF catalyst had excellent O–H activation ability and strong *H adsorption capacity. These *H species were transferred from the Ni sites to the *NO adsorption intermediates located on the Cu sites, providing a continuous supply of *H to Cu, thereby promoting the formation of *NOH intermediates and enhancing the hydrogenation process of the electrocatalytic NO3RR.

Shining light on green chemistry: BODIPY-infused porphyrin nanocomposite-enzymatic photocatalyst boosts selective aldehydes hydrogenation and organic transformation under solar spectrum

Photo-bio enzyme coupled biotransformation solar radiation driven processes grasp promising in the production of solar driven organic chemicals. Here we reported the synthesis and development of (NH2)4TPP@BODIPY photocatalyst, which was constructed from 5,10,15,20 tetrakis (4 amino phenyl) porphyrin and BODIPY {5,5-difluoro-3,7-bis((E)-4-nitrobenzylidene)-10-(4-nitrophenyl)-5,7-dihydro-3H-4l4,5l4-dipyrrolo[1,2-c:2′,1′-f][1,3,2]diazaborinine} molecule through poly-condensation mechanism resulting in the composite formation which manifest excellent light harvesting properties and photocatalytic reactions with suitable satisfactory band gap and formation of huge electrons channels which bears the organic transformation (98 %) and photo-regeneration of NADH (66.92 %) in 60 min which further enhances reduction of aldehyde resulting alcohol production. The highly selective aldehyde hydrogenation process is proposed via coordination of alcohol dehydrogenase with (NH2)4TPP@BODIPY assistant reduces from the coupling process; regeneration of nicotinamide adenine dinucleotide (NADH). Our results show an excellent benchmark for the NAD+ co-factor coupled solar-driven alcohol production via (NH2)4TPP@BODIPY photocatalyst.

Alkali‐Mediated/Catalyzed Transition‐Metal‐Free Tandem Reaction Triggered by the Borrowing Hydrogen and Aerobic Dehydrogenation Processes of Alcohols

AbstractThe transformation of alcohols to important classes of compounds is a central topic in chemistry because they are abundant, renewable, and attractive building blocks. The alkali‐mediated/catalyzed borrowing hydrogen and aerobic dehydrogenation processes of alcohols open a new and sustainable access for the alcohol conversion under transition‐metal‐free conditions. In this review, we summarize the recent alkali‐mediated/catalyzed sequential reactions involving the borrowing hydrogen and aerobic dehydrogenation processes of alcohols. Furthermore, this review not only introduces the tentative pathways of these transformations, but also discusses the role of alkali, solvent effects, and substrate reactivity on these reactions.

Effect of mesh aluminum alloy on hydrogen and propane explosion characteristics

In order to explore the effect of mesh aluminum alloy (MAA) on the explosion characteristics of different types of gases, experiments were conducted by filling MAA in hydrogen and propane explosion pipes. The explosion characteristic parameters of hydrogen and propane with different volume fractions under the action of MAA were obtained. The chain reaction process and thermodynamic reaction mechanism of hydrogen and propane explosions were studied using the numerical simulation software CHEMKIN-PRO and Materials Studio. The experimental results show that MAA significantly promotes hydrogen explosions but inhibits propane explosions. Simulation results show that ·H, ·O, and ·OH are key radicals in the hydrogen explosion process. As the hydrogen volume fraction increases, the number of radicals in the reaction system also increases. When MAA is filled in the hydrogen explosion test pipe, the turbulence of the flame structure inside the pipe increases the collision probability between key radicals such as ·H, ·O, and ·OH, sharply increasing the temperature of the explosion reaction system, resulting in a promoting effect of MAA on hydrogen explosions. When MAA is introduced into the propane explosion test pipe, it creates a barrier and wall effect. This reduces the number of key radicals in the reaction system and lowers the likelihood of radical collisions, which slows down the rates of multiple chain reactions and inhibits the propane explosion. Thermodynamically, it can be seen that propane requires more energy than hydrogen for key elementary reactions to explode, making it more difficult to react.

Anchoring Frustrated Lewis Pair Active Sites on Copper Nanoclusters for Regioselective Hydrogenation.

In recent years, the concept of Frustrated Lewis Pairs (FLPs), which consist of a combination of Lewis acid (LA) and Lewis base (LB) active sites arranged in a suitable geometric configuration, has been widely utilized in homogeneous catalytic reactions. This concept has also been extended to solid supports such as zeolites, metal oxide surfaces, and metal/covalent organic frameworks, resulting in a diverse range of heterogeneous FLP catalysts that have demonstrated notable efficiency and recyclability in activating small molecules. This study presents the successful immobilization of FLP active sites onto the surface of ligand-stabilized copper nanoclusters with atomic precision, leading to the development of copper nanocluster FLP catalysts characterized by high reactivity, stability, and selectivity. Specifically, thiol ligands containing 2-methoxyl groups were strategically designed to stabilize the surface of [Cu34S7(RS)18(PPh3)4]2+ (where RSH = 2-methoxybenzenethiol), facilitating the formation of FLPs between the surface copper atoms (LA) and ligand oxygen atoms (LB). Experimental and theoretical investigations have demonstrated that these FLPs on the cluster surface can efficiently activate H2 through a heterolytic pathway, resulting in superior catalytic performance in the hydrogenation of alkenes under mild conditions. Notably, the intricate yet precise surface coordination structures of the cluster, reminiscent of enzyme catalysts, enable the hydrogenation process to proceed with nearly 100% selectivity. This research offers valuable insights into the design of FLP catalysts with enhanced activity and selectivity by leveraging surface/interface coordination chemistry of ligand-stabilized atomically precise metal nanoclusters.

Plasma-assisted Synthesis of Methanol Through Hydrogenation of Carbon Dioxide with Non-Noble Metal Mixed Oxide Catalysts.

The utilization of carbon dioxide through chemical conversion is a promising approach for the recycling of carbon resources. Despite well-developed industrial processes for CO2 hydrogenation to methanol, the effective use of CO2 as a feedstock remains challenging because of the costly requirements of high temperature and reaction pressure. In this paper, we report the methanol synthesis from CO2 and hydrogen using a dielectric barrier discharge (DBD) reactor under atmospheric pressure with a nickel-cerium-aluminum mixed oxide (Ni/Ce-Al MOx) catalyst. The combined use of plasma and Ni/Ce-Al MOx catalyst was observed to yield 13.3±0.4% of methanol, favorably compared to the 2.6±0.5% yield of the case without catalyst. Microscopy images, selected area electron diffraction patterns, and energy-dispersive X-ray analysis confirmed the presence of fluorite-structured ceria, nickel, and nickel oxide particles in the catalysts. The reaction mechanism for the plasma-assisted hydrogenation of CO2 was hypothesized to involve a carbide formation pathway due to the presence of carbide confirmed by X-ray photoelectron spectroscopic characterization.

Hydrogen Refueling Stations: A Review of the Technology Involved from Key Energy Consumption Processes to Related Energy Management Strategies

Over the last few years, hydrogen has emerged as a promising solution for problems related to energy sources and pollution concerns. The integration of hydrogen in the transport sector is one of the possible various applications and involves the implementation of hydrogen refueling stations (HRSs). A key obstacle for HRS deployment, in addition to the need for well-developed technologies, is the economic factor since these infrastructures require high capital investments costs and are largely dependent on annual operating costs. In this study, we review hydrogen’s application as a fuel, summarizing the principal systems involved in HRS, from production to the final refueling stage. In addition, we also analyze the main equipment involved in the production, compression and storage processes of hydrogen. The current work also highlights the main refueling processes that impact energy consumption and the methodologies presented in the literature for energy management strategies in HRSs. With the aim of reducing energy costs due to processes that require high energy consumption, most energy management strategies are based on the use of renewable energy sources, in addition to the use of the power grid.

Diimide-Mediated Hydrogenation of Nitrile Butadiene Rubber

The hydrogenation of nitrile butadiene rubber (NBR) has shown great potential for improving its physical, thermal, mechanical, and chemical stability. Hydrogenation process of NBR in this work involved the utilization of diimide produced from the interaction between hydrazine hydrate (N2H4) and hydrogen peroxide (H2O2), with the addition of boric acid as a promoter. Attenuated total reflectance Fourier transform infrared (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) were used to evaluate the degree of hydrogenation, glass transition, thermal stability, and rubber crystallinity, respectively. The highest hydrogenation degree was 99%, which resulted in a 57% gel content. Upon hydrogenation, both the glass transition temperature (Tg) and decomposition temperature (Td) increased. The hydrogenated rubber samples generally showed an amorphous state, except for the 99% hydrogenated sample, which displayed a semi-crystalline state. However, using diimide for direct hydrogenation yields a side reaction from the free radicals in the system, which leads to gel formation. Optimization was accomplished by employing the response surface methodology (RSM), which entailed manipulating parameters such as the total solid content (TSC) of NBR, reaction time, and the mole ratio of H2O2 to N2H4, to reduce the percentage of gel content. The RSM analysis identified the optimum reaction conditions as a 1:1 mole ratio of H2O2: N2H4 and 25% TSC, with a reaction time of 8 h, which yielded 32% gel content percentage, where a mole ratio of H2O2 to N2H4 and reaction time indicated a synergistic effect, whereas TSC denoted an antagonistic effect.

Hydrogen-Induced Topotactic Phase Transformations of Cobaltite Thin Films.

Manipulating physical properties through ion migration in complex oxide thin films is an emerging research direction to achieve tunable materials for advanced applications. While the reduction of complex oxides has been widely reported, few reports exist on the modulation of physical properties through a direct hydrogenation process. Here, we report an unusual mechanism for hydrogen-induced topotactic phase transitions in perovskite La0.7Sr0.3CoO3 thin films. Hydrogenation is performed upon annealing in a pure hydrogen gas environment, offering a direct understanding of the role that hydrogen plays at the atomic scale in these transitions. Topotactic phase transformations from the perovskite (P) to hydrogenated-brownmillerite (H-BM) phase can be induced at temperatures as low as 220 °C, while at higher hydrogenation temperatures (320-400 °C), the progression toward more reduced phases is hindered. Density functional theory calculations suggest that hydroxyl bonds are formed with the introduction of hydrogen ions, which lower the formation energy of oxygen vacancies of the neighboring oxygen, enabling the transition from the P to H-BM phase at low temperatures. Furthermore, the impact on the magnetic and electronic properties of the hydrogenation temperature is investigated. Our research provides a potential pathway for utilizing hydrogen as a basis for low-temperature modulation of complex oxide thin films, with potential applications in neuromorphic computing.

Properties of palladium-phosphorus catalysts supported on HZSM-5 zeolite in the direct synthesis of hydrogen peroxide

The properties of Pd/HZSM-5 and Pd–nP/HZSM-5 catalysts in direct synthesis and side processes of decomposition and hydrogenation of H2O2 under mild conditions in ethanol and aqueous-ethanol medium in the presence of an acid inhibitor were studied. Using HR-TEM, XRD and ICP MS methods, it was shown that as a result of modification with phosphorus, X-ray amorphous highly dispersed systems are formed, which represent structurally disordered solid solutions of phosphorus in palladium. The main reasons for the promoting effect of phosphorus on the yield of H2O2 are considered. It has been established that, along with phosphorus and acid modifiers, the use of a zeolite support in the H-form favors the inhibition of the side process of H2O2 decomposition.

Data-Driven Approaches for Predicting Catalyst Performance in CO2 Hydrogenation

This paper explores the critical role of data collection and preparation in leveraging machine learning techniques for predicting catalyst performance in CO2 hydrogenation processes. As the global community seeks sustainable solutions to mitigate carbon emissions, understanding the efficiency of catalysts in converting CO2 into valuable chemicals becomes increasingly important. The study discusses various types of data utilized in this context, including both experimental and simulation data, while highlighting their significance in comprehensively understanding key factors such as reaction rates, selectivity, and catalyst stability. For instance, the ability of a catalyst to selectively produce desired products over others can significantly impact the overall economic viability of CO2 hydrogenation processes. Furthermore, stability data sheds light on the longevity and durability of catalysts, revealing insights into deactivation mechanisms that can occur due to factors like sintering, poisoning, or leaching of active sites. On the other hand, simulation data generated from advanced computational methods such as density functional theory (DFT) and molecular dynamics (MD) provides a deeper understanding of the electronic and structural properties of catalysts. These computational techniques allow researchers to predict reaction pathways, activation energies, and the behavior of intermediate species, thereby complementing experimental findings and guiding the design of more effective catalysts. The paper also emphasizes the importance of utilizing publicly available databases and collaborative research datasets, which serve to enhance data accessibility and foster scientific collaboration among researchers in the field. By pooling resources and sharing findings, the scientific community can accelerate the discovery and optimization of novel catalysts. Additionally, the study outlines essential steps in the data preparation process, including rigorous data cleaning, preprocessing, and feature selection, all of which are crucial for ensuring the quality and reliability of the data used in machine learning models. The paper discusses the implementation of cross-validation techniques and performance metrics that help evaluate and validate model predictions, ensuring that the developed models generalize well to unseen data.

Room-temperature rapid oxygen monitoring system in high humidity hydrogen gas environment towards water electrolysis application

Water electrolysis is one of the key processes for carbon-free hydrogen (H2) generation, yet it inherently presents the risk of oxygen (O2) permeation, a significant concern that must be addressed. Contrary to external atmospheric conditions, the environment within a water electrolysis system is characterized exclusively by high-purity H2, little O2, and moisture (H2O). However, there has been limited research on sensors capable of detecting O2 crossover in such a pure H2 atmosphere under high humidity conditions. In this study, we developed an electrolysis O2 monitoring (E-OM) sensor based on a semiconducting metal oxide (SMO) that can operate at a room-temperature with such high humidity through photoactivation with 365 nm LED light. A porous In2O3 nanofilm, prepared by glancing angle deposition (GLAD), was used as the gas sensing material, and copper nanoparticles (Cu NPs) were decorated on the In2O3 surface through electron beam evaporation to accelerate the O2 adsorption. Remarkably, the E-OM sensor showed a humidity-independent response to O2 gas in the H2 atmosphere. Meanwhile, since the response of the E-OM sensor itself was not fast enough for water electrolysis system application, convolutional neural network (CNN)-based signal processing in the time domain was applied. As a result, our E-OM sensor system could predict O2 concentrations from 0 to 2 vol% in an H2 environment with a relative humidity (RH) of 30–90 %, and the detection time was under 5 s. This development could enable safe, rapid, and cost-effective monitoring of O2 crossover in H2 production infrastructure.

Revisiting the Reviewed: A Meta‐Analysis of Computational Studies on Transition Metal‐Catalyzed Hydrogenation Reactions

AbstractThis review of reviews attempts to systematically analyze the recent advancements in transition metal‐catalyzed hydrogenation reactions as discussed in previous review articles, emphasizing the computational insights that enhance our understanding of reaction mechanisms. It highlights the efficacy of density functional theory (DFT) in calculating free energies, exploring the mechanistic pathways and kinetics of hydrogenation processes and, focusing on substrates such as alkenes, alkynes, amides, imines, nitriles, and carbon dioxide. The review details significant studies where computational models help predict reaction outcomes and aid in catalyst design. Notable discussions include the role of solvent effects and metal‐ligand interactions, which are crucial for reactivity and selectivity but often underestimated in computational models. The review concludes with current computational challenges and prospects, suggesting enhanced models and experimental collaborations to refine catalyst design.

Synthesis and Investigation of Catalytic Properties of Metal-Polymer Nanocomposites Based on Unsaturated Polyester Resins

This paper focuses on the hydrogenation process in metal-polymer complexes based on copolymers of polypropylene glycol fumarate phthalate and polypropylene glycol maleate phthalate, using acrylic acid and immobilized cobalt metal particles as catalysts. A classical reaction of the electrocatalytic hydrogenation of pyridine to piperidine was applied. SEM and dynamic light scattering were utilized to investigate the average size and dispersity of cobalt metal nanoparticles. The experimental findings show that the efficiency of hydrogenation can be improved by increasing the temperature from 25 to 40 °C and the current to 2 A. More specifically, increasing the temperature to 40 °C promotes swelling of the polymer and its transition from a globular collapsed state to an open one, which leads to an increase in the number of active catalytic centers and, as a consequence, acceleration of the hydrogenation process. Increasing the current strength to 2 A also helps to increase the rate of the hydrogenation process. Further increasing the current to 3 A is undesirable due to an increase in the yield of by-products and a decrease in the yield of the target product, piperidine. Based on a comparative analysis, it was established that the use of a copolymer of polypropylene glycol maleate phthalate with acrylic acid as the polymer matrix base is the most preferable for obtaining polymer-metal complexes with nanosized cobalt.

Evaluation of Cobalt, Nickel, and Palladium Complexes as Catalysts for the Hydrogenation and Improvement of Oxidative Stability of Biodiesel

Developing effective catalysts that can selectively hydrogenate C=C bonds in biodiesel samples is vital as it tackles the major problem of oxidative stability, which greatly limits the utilization of biodiesel as an alternative fuel. In this work, Co, Ni, and Pd catalysts stabilized with the bidentate nitrogen ligands N-(3-(triethoxysilyl)propyl)pyridin-2-ylmethylimine and N-(3-(triethoxysilyl)propyl)picolinamide were synthesized, characterized, and used as pre-catalysts in the transfer hydrogenation of C=C bonds in fatty acid methyl esters. The active catalysts from the Co, Ni, and Pd complexes sequentially hydrogenate the C18:2 chains to C18:1, which is further converted to C18:0 in the FAMEs of both methyl linoleate and jatropha biodiesel. The hydrogenation process was kinetically controlled, and after 3 h it yielded a biodiesel sample that contained 25.83% C16:0, 12.52% C18:2, 41.54% C18:1, 14.47% C18:0 and 3.0% C18:2 isomers. The un-hydrogenated jatropha diesel, hydrogenated jatropha diesel, and a B20 blend of jatropha were tested for susceptibility to oxidation reactions using the Rancimat method and FTIR spectroscopy, and the partial hydrogenation had improved the induction period by 3 h.

Techno-economic-environmental assessment of green hydrogen and ammonia synthesis using solar and wind resources for three selected sites in Egypt

The primary motivation of the present study is to mitigate the severe impact of ongoing energy resource shortages, while offering clean and sustainable energy carriers, such as hydrogen and ammonia. The present system mainly encompasses water splitting and the Haber-Bosch (HB) processes for green hydrogen and ammonia synthesis using solar and wind power, respectively. Pointwise quantification analyses are conducted to quantify the power, hydrogen, and ammonia as well as the economic parameters, specifically the levelized cost of energy (LCOE), levelized cost of hydrogen (LCOH), and levelized cost of ammonia (LCOA). This analysis is based on meteorological data from three sites in Egypt, considering the specific water and nitrogen requirements for hydrogen and ammonia synthesis, respectively. Furthermore, carbon dioxide mitigation from solar and wind systems is estimated. These respective sites are Jarjoub on the coastlines of the Mediterranean Sea, and Ain Sokhna and Jabal Al-Zait on the coastlines of the Red Sea. The results indicate that the lowest values of LCOE, LCOH, and LCOA are 12.58 $/MWh, 1.91 $/kg H2, and 396.1 $/Ton NH3, respectively, which were attained using solar resources at Ain Sokhna geographical site at the Red Sea. Besides, Jarjoub, which is located in the Mediterranean Sea, could attain LCOH of 2.15 $/kg, which is still a promising option due to its export potential to Europe. However, the use of wind resources is incompetent for solar counterparts in the respective sites; their potential application in Egypt is still promising. The results demonstrate that Jabal Al-Zait stands as a favorable location for green power, hydrogen, and ammonia synthesis using wind resources, which has LCOE, LCOH, and LCOA of 23.67 $/MWh, 2.75 $/kg H2, and 547.8 $/Ton NH3, respectively.

The Loss of Interfacial Water-Adsorbate Hydrogen Bond Connectivity Position Surface-Active Hydrogen as a Crucial Intermediate to Enhance Nitrate Reduction Reaction.

The electrochemical nitrate reduction reaction (NO3RR) offers a promising solution for remediating nitrate-polluted wastewater while enabling the sustainable production of ammonia. The control strategy of surface-active hydrogen (*H) is extensively employed to enhance the kinetics of the NO3RR, but atomic understanding lags far behind the experimental observations. Here, we decipher the cation-water-adsorbate interactions in regulating the NO3RR kinetics at the Cu (111) electrode/electrolyte interface using AIMD simulations with a slow-growth approach. We demonstrate that the key oxygen-containing intermediates of the NO3RR (e.g., *NO, *NO2, and *NO3) will stably coordinate with the cations, impeding their integration with the hydrogen bond network and further their hydrogenation by interfacial water molecules due to steric hindrance. The *H can migrate across the interface with a low energy barrier, and its hydrogenation barrier with oxygen-containing species remains unaffected by cations, offering a potent supplement to the hydrogenation process, playing the predominant factor by which the *H facilitates NO3RR reaction kinetic. This study provides valuable insights for understanding the reaction mechanism of NO3RR by fully considering the cation-water-adsorbate interactions, which can aid in the further development of the electrolyte and electrocatalysts for efficient NO3RR.