N2 Flow Research Articles

Effect of adduct synthesis parameters on the ethylene polymerization kinetics of Ziegler Natta catalysts

AbstractHere, it is aimed to clarify the structure‐performance relationship in MgCl2 based Ziegler Natta catalysts toward ethylene polymerizations. In this regard, 11 different adduct precursors were prepared through industrially appreciated melt quenching method employing various: (i) reaction times for dissolving magnesium chloride inside ethanol; (ii) ethanol/MgCl2 molar ratios in the feed; (iii) heating rates during thermal dealcoholation; (iv) N2 flows during thermal dealcoholation and (v) alcohol content after thermal dealcoholation. Among the studied parameters, heating rate and N2 flow during thermal dealcoholation have the most pronounced effect on the porosity and particle size of the resulted adducts. Related Ziegler Natta catalysts were subsequently employed in ethylene polymerizations. According to the kinetic curves, catalyst productivity and form of kinetic curve (as decay or build‐up type) can be precisely tailored by proper choosing of the mentioned variables during adduct synthesis. Microstructure analysis of the prepared polyethylenes reveals that alcohol content in the final adduct has the most significant effect on the H2 response, in terms of molar mass and its distribution, of the related Ziegler Natta catalysts. The overall results help polyethylene producers in choosing proper reaction conditions during adduct synthesis for the production of different polymer grades, when productivity or H2 response is targeted.

Effect of nitrogen content on the mechanical and biological properties of tantalum nitride coatings

In this article, the effect of nitrogen content on the mechanical and biological properties of Tantalum Nitride coatings has been studied. TaN coatings with different N concentrations were deposited on glass slides and medical metals by magnetron sputtering in Ar + N2 atmosphere to improve the adhesion strength and biocompatibility of PVD coatings. The morphology, composition, mechanical properties, and biology of the TaN films were characterized at varying N levels, which were obtained by adjusting the flow rate of N2 at 5, 10, and 15 sccm. Results showed that hardness of the coating increased when N2 was added. The film transitioned from γ-Ta2N to ε-TaN and δ-TaN when N2 gas flow rate increased. The γ-Ta2N coating had the highest hardness (37.30 GPa). The adhesion strength of the coatings was increased with N2 flow rate and then decreased, the ε-TaN film deposited at a N2 flow rate of 10 sccm had the highest adhesion strength (18.12 N). TaN coating deposited at a N2 flow rate of 10 sccm showed the highest cell growth rate (151.77 %) and number of cells on the surface. The friction curve of the δ-TaN coating subjected to 15 sccm N2 flow rate exhibited excellent wear resistance with minimum fluctuation. According to the aforementioned findings, TaN coatings deposited under various nitrogen flow rates have significantly improved in adhesion strength, wear resistance, hardness, and biocompatibility, which offers a good reference value for research on the surface modification of medical metal and a good replacement material for the field of medical implantation.

Study on characteristics, hydrogen-rich gas, bio-oil production, and process optimization of co-pyrolysis of sewage sludge and wheat straw

Sewage sludge (SS) and wheat straw (WS) are wastes that need to be treated urgently. In this research, the co-pyrolysis of SS and WS was investigated utilizing a thermogravimetric analyzer (TG) and a fixed bed. Using the Coats-Redfern approach, the effects of the mix ratio and the interactions of the SS and WS were investigated, and the effects of mix ratio, N2 flow rate, and pyrolysis temperature were examined for fixed bed pyrolysis. The response surface method (RSM) was applied in fixed bed pyrolysis to optimize the process. Increasing WS ratio can reduce pyrolysis residual rate to 23.8% for TG analysis. The reaction activation energy (E) increased with WS ratio. For the co-pyrolysis, there were substantial interactions between 200 and 400°. For fixed bed pyrolysis, syngas and bio-oil yields were mainly affected by N2 flow rate and pyrolysis temperature. The components with the highest amount in bio-oil gradually changed from aliphatic to aromatic hydrocarbons as the WS proportion grew, demonstrating that WS pyrolysis produced mostly aromatic compounds whereas SS pyrolysis produced more aliphatic compounds. Temperature 600 °C, sludge mixing ratio 32%, flow rate 2.5L/min, anticipated maximum H2 0.0421 m3/kg, and maximum bio-oil of 50.7114 g/kg are the best circumstances according to RSM.

Three-dimensional melamine sponge hollow carbon/Ni3ZnC0.7/carbon nanotubes with tunable high-performance microwave absorption performance

Constructing three-dimensional microstructure with special morphology is an important method to improve the flexibility, low density and high performance of absorbing materials. Herein, Ni3ZnC0.7/carbon nanotubes/melamine sponge hollow carbon (NZC/CNTs/SHC) composites were prepared by vacuum filtrating precursor containing NiZn ions and CNTs followed with calcining under N2 flow. The loading of NZC/CNTs can be tuned by controlling the filtrating time of 0.5, 1 and 2 h. The Ni3ZnC0.7 and CNTs were uniformly dispersed on the surface of melamine sponge carbon skeleton and the carbon shows hollow structure. The 2-NZC/CNTs/SHC composite (filtrating time of 2 h) exhibited a minimum reflection loss (RL) value of − 114.5 dB (1.3 mm) and an effective absorption bandwidth (EAB, RL<−10 dB) of 12.5 GHz at a matching thickness of 1.9 mm. The outstanding wave-absorbing properties of NZC/CNTs/SHC composites can be attributed to their unique hollow structure, which results in multiple reflections and scattering, interface/dipole polarization, improved dielectric and magnetic attenuation capability.

High Oxide‐Ion Conductivity through the Interstitial Oxygen Site in Sillén Oxychlorides

AbstractOxide‐ion conductors are gaining attention as future materials in energy applications, such as solid oxide fuel cells. Many Bi‐containing compounds exhibit high oxide‐ion conductivity via conventional vacancy mechanism. However, interstitial oxide‐ion conduction is rare in Bi‐containing materials. Herein, high oxide‐ion conductivity is reported through interstitial oxygen sites in Sillén oxychlorides, LaBi2−xTexO4+x/2Cl (Bi2LaO4Cl‐based oxychlorides). Oxide‐ion conductivity of LaBi1.9Te0.1O4.05Cl is 20 mS cm−1 at 702 °C, and higher than best oxide‐ion conductors as Bi2V0.9Cu0.1O5.35 below 201 °C. Despite of the presence of Bi and Te species, LaBi1.9Te0.1O4.05Cl shows extremely high chemical and electrical stability at 400 °C from oxygen partial pressure 10−25 to 0.2 atm and high chemical stability under CO2 flow, wet 5% H2 in N2 flow, and air with natural humidity. Neutron scattering length density analysis, DFT calculations, and ab initio molecular dynamics simulations indicate that the extremely high oxide‐ion conduction is attributed to cooperative diffusion through interstitial oxygen sites (interstitialcy diffusion mechanism) in triple fluorite‐like layers. The present findings demonstrate the ability of LaBi2−xTexO4+x/2Cl as superior oxide‐ion conductors, which can open new horizons for oxide‐ion conductors.

9.1: Effect of Nitrogen Doping Content on Electrical Properties and Stability of a‐IGZO TFT

To improve the electrical properties and stability of thin‐film transistor (TFT) based on the indium gallium zinc oxide (IGZO) channel, the effect of nitrogen‐doping content on the electrical properties of IGZO films and the IGZO TFT were evaluated. It is found that the mobility and carrier concentration of IGZO films gradually decreases ( μ from 18.11 to 11.25 cm2/ V.s, n from 1.76×107 to 4.38×107 cm‐3 ) with the increase of N2 flow content (0‐8sccm). N‐doping can evidently improve the positive bias stress(PBS) stability of IGZO TFT. Typically, the low‐content N‐doping (1 sccm) can significantly boost the stability of IGZO:N TFT (ΔVth = 3.3 V vs ΔVth=9.54 V for the undoped counterpart), while the electrical properties is at almost no degradation with the mobility and on‐off current ratio (Ion/Ioff)as high as 16.59 cm2 /V.s and 3.55×107, and the sub‐threshold swing (SS) and threshold voltage (Vth) as low as 0.32 V/dec and 1.49 V, respectively. These outstanding reliability performance indicates that the N‐doping with appropriate low‐content is a facile and economical way to improve the electrical properties and stability of IGZO TFT.

Preliminary Study on The Bio-Oil Production from Multi Feed-Stock Biomass Waste via Fast Pyrolysis Process

Biomass is a good resource for renewable energy. Biomass can be converted into bio-fuel (bio-oil) through a catalytic fast pyrolysis process. Previous studies only used single feedstock biomass as raw material for bio-oil production. In this study, bio-oil production is based on a multi-feedstock biomass waste consisting of rice husk, sugar cane bagasse, and palm oil empty fruit bunch. The mixture of biomass waste as a raw material is expected to enhance the yield and quality of the bio-oil produced. This study aimed to investigate the bio-oil products obtained from catalytic pyrolysis of the biomass waste mixture. Mixture Design from Design Expert was used to study the effect of biomass composition on the bio-oil products. Each biomass, i.e., rice husk, sugar cane bagasse, and palm oil empty fruit bunch, was previously chopped and sieved into a uniform 60 mesh. The pyrolysis process was conducted at 500°C with an N2 flow rate of 3 L min-1. The mixture of biomass waste husks contains more phenolic compounds than single-feedstock. The chemical characterization also showed that the multi-feedstock bio-oil compound was dominated by aldehydes, esters, and phenolic compounds.

Producing magnetite concentrate from iron tailings via suspension magnetization roasting: A pilot-scale study

ABSTRACT In the process of iron ore beneficiation, a considerable amount of iron was lost to the tailings, resulting in the waste of resources and environmental pollution. In this study, an innovative technology of pre-concentration followed by suspension magnetization roasting and low-intensity magnetic separation (PSRM) was used to recover iron from iron tailings. The iron grade of the roasted feed ores was increased from 15.68% to 33.19% by pre-concentration process. Subsequently, the suspension magnetization roasting was performed to transform the weak magnetic minerals into magnetite, and magnetite concentrate was obtained via low-intensity magnetic separation. The effects of feeding rate, roasting temperature, reducing gas CO flow rate, and fluidizing gas N2 flow rate during suspension magnetization roasting were investigated, and the pilot-scale equipment was conducted for 72 h continuously under the optimum roasting conditions. The phase transformation and magnetic property variations of the minerals before and after roasting were analyzed by X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM), respectively. The results showed that an iron concentrate with iron grade of 63.04% and total iron recovery of 48.40% was obtained under the optimum roasting conditions: feeding rate of 111.70 kg/h, roasting temperature of 550°C, CO flow rate of 4.0 m3/h, and N2 flow rate of 2.0 m3/h. The hematite and siderite in tailings were transformed into magnetite with an average magnetic conversion rate of 86.46%. This innovative PSRM technology provides an important reference for the resource utilization of solid waste and the recovery of iron from iron tailings.

Improved Crystallinity of Annealed 0002 AlN Films on Sapphire Substrate

AlN is a piezoelectric material used in telecommunication applications due to its high surface acoustic wave (SAW) velocity, stability, and mechanical strength. Its performance is linked to film quality, and one method to achieve high-quality films goes through the process of annealing. Consequently, c-orientated AlN film with a thickness of 1.1 μm deposited on sapphire was annealed at temperatures of 1100 °C and 1150 °C in a N2 controlled atmosphere. This was compared to annealing at 1100 °C, 1450 °C, and 1700 °C with N2 flow in an open atmosphere environment. Sample rotation studies revealed a significant impact on the ⍵-2θ X-ray rocking curve. A slight variation in the film crystallinity across the wafer was observed. After the annealing, it was found that the lattice parameter c was increased by up to 2%, whereas the screw dislocation density dropped from 3.31 × 1010 to 0.478 × 1010 cm-2, and the full width at half maximum (FWHM) of reflection (0002) was reduced from 1.16° to 0.41° at 1450 °C. It was shown that annealing in a N2-controlled atmosphere plays a major role in reducing the oxidation of the AlN film, which is important for acoustic wave devices where the electrodes are placed directly on the piezoelectric substrate. The face-to-face arrangement of the samples could further reduce this oxidation effect.

Effects of nitrogen flow rate on the microstructure and mechanical and tribological properties of TiAlN films prepared via reactive magnetron sputtering

In this study, TiAlN ceramic films were fabricated via reactive magnetron sputtering on a Ti6Al4V titanium alloy substrate. The effects of N2 flow rates on the microstructure and mechanical and tribological properties of the films were systematically studied. With increasing N2 flow rate, the films underwent a morphological evolution from a fine columnar structure to a coarse structure with holes and microcracks. In addition, the preferred orientation of the films varied from TiAlN (220) to the (111) plane. However, a high N2 flow rate (≥20sccm) resulted in target poisoning and reduced the deposition rate, which resulted in defects such as cavities and holes on the surface. Moreover, with increasing N2 flow rate, the hardness and elastic modulus first increased and then reduced owing to grain refinement. The films deposited at a N2 flow rate of 16 sccm exhibited the smallest wear width and the lowest wear rate. As the N2 flow rate increased from 12 to 24 sccm, the wear mechanism of the films changed from abrasive and adhesion wear to abrasive wear caused by severe plastic deformation, which was directly related to the microstructural evolution and mechanical properties.

CoMn catalysts derived from partial decomposed layered CoMn-MOF materials for higher alcohol synthesis from syngas

Direct and selective conversion of syngas to higher alcohols (C2+OH, HA) is highly attractive but remains challenges in improving the high catalytic performance. Herein, a series of catalysts were prepared by thermal decomposing layered-structured CoMn-MOF materials and used in the HA synthesis.Characterization results showed that the MOF framework could partially maintain after calcination at 350 °C under N2 flow, in which the Co2+ species can provide extra non-dissociative adsorption CO sties, leading to an improved alcohol selectivity. And the addition of manganese could promote the cobalt dispersion and Co2C formation. The synergistic catalysis of these active species allowed the optimal CoMn-350 catalyst to display a superior selectivity to HA, specifically the alcohol selectivity reached 57.5% and the distribution of C2+OH in total alcohols was up to 82.4 % when the CO conversion was 51.5%. The catalyst with remaining MOF framework also showed an excellent stability during 250 h reaction. This work highlights a feasible strategy for the design of highly efficient catalysts for HA synthesis via the partial decomposing MOF materials.

Deposition processing and surface metrology of MoNx thin films by design of experiment and single variable (nitrogen flow rate) methods

In this study, the Taguchi design of experiment (DOE) was performed to optimize the deposition process of MoNx thin films using unbalanced magnetron sputtering (UBMS). Further single-variable experiments based on the sensitive parameter derived from the Taguchi experiments were conducted to investigate the effect of the parameter on the phase evolution, structure, and properties of the MoNx thin films. The MoNx thin films were deposited using DC-UBMS. Four controlling factors: N2 flow rate, substrate bias voltage, substrate temperature, and substrate rotational speed were selected in the Taguchi L9 matrix experiment. Electrical resistivity and hardness were chosen as the quality characteristics for the optimization. Analysis of variance (ANOVA) and analysis of mean (ANOM) were performed to identify the sensitive parameters and the optimum conditions. The confirmation test results for the optimizations of hardness (SH) and electrical resistivity (SR) were within the predicted ranges, and therefore the feasibility and reliability of the Taguchi optimization were verified. The results of ANOVA showed that nitrogen flow rate was the most sensitive factor. The optimum condition for the electrical resistivity was chosen to be the reference for the single-variable experiments, and nitrogen flow rate was selected as the controlling variable. The MoNx specimens in the single-variable experiment showed prevailing (200) texture that could be attributed to the lowest surface energy associated with (200) plane and the base metal steering effect by Mo (110). The results of single-variable experiments indicated that the retained Mo metal phase played an important role in hardness, electrical resistivity, and residual stress.

Pyrolysis Atmospheres and Temperatures Co-Mediated Spectral Variations of Biochar-Derived Dissolved Organic Carbon: Quantitative Prediction and Self-Organizing Maps Analysis.

Biochar-derived dissolved organic carbon (BDOC), as a highly activated carbonaceous fraction of biochar, significantly affects the environmental effect of biochar. This study systematically investigated the differences in the properties of BDOC produced at 300-750 °C in three atmosphere types (including N2 and CO2 flows and air limitation) as well as their quantitative relationship with biochar properties. The results showed that BDOC in biochar pyrolyzed in air limitation (0.19-2.88 mg/g) was more than that pyrolyzed in N2 (0.06-1.63 mg/g) and CO2 flows (0.07-1.74 mg/g) at 450-750 °C. The aliphaticity, humification, molecular weight, and polarity of BDOC strongly depended on the atmosphere types as well as the pyrolysis temperatures. BDOC produced in air limitation contained more humic-like substances (0.65-0.89) and less fulvic-like substances (0.11-0.35) than that produced in N2 and CO2 flows. The multiple linear regression of the exponential form of biochar properties (H and O contents, H/C and (O+N)/C) could be used to quantitatively predict the bulk content and organic component contents of BDOC. Additionally, self-organizing maps could effectively visualize the categories of fluorescence intensity and components of BDOC from different pyrolysis atmospheres and temperatures. This study highlights that pyrolysis atmosphere types are a crucial factor controlling the BDOC properties, and some characteristics of BDOC can be quantitatively evaluated based on the properties of biochar.

Catalytic deoxygenation with SO42--Fe2O3/Al2O3 catalyst: Optimization by Taguchi method

This work investigates the optimization of reaction parameters with the Taguchi method for catalytic deoxygenation of waste cooking oil (WCO) as an alternative renewable fuel process. Commercial sulphated-ferric (II) oxide/alumina oxide catalyst has the potential as a deoxygenation catalyst due to its good physicochemical properties which enhance the removal of oxygenated species. The obtained pyrolysis oil analysed by GC-MS revealed the selectivity of the pyrolysis oil mostly in the range of light diesel and kerosene fraction. From an analysis of variance (ANOVA), temperature awarded the most significant impact (86.62%) in this catalytic deoxygenation as compared to three other parameters followed by reaction time > N2 flow > catalyst loading. From the GC-MS analysis, the maximum renewable diesel fraction of 49.66% was obtained at 400 °C, 1 wt% of catalyst, 90 min of reaction time and 20 cm3/min N2 flow. The predicted model by Taguchi in the present study validated by the experimental work shows a promising application in optimising the catalytic pyrolysis process for future use.

Optimization of process parameters for conventional pyrolysis of algal biomass into bio–oil and bio–char production

The current study involves the conventional pyrolysis of algal biomass under a batch fixed–bed reactor for the analysis of temperature, retention time, N2 flow rate on pyrolysis product yields Response Surface Methodology by Box–Behnken Design method was used for obtaining optimum parameters. The operating conditions were varied in the range of 450–575 °C, 30–60 min and 0.1–0.5 l/min, respectively. The regression model with 95% confidence level resulted in the high value of R2=98.42% with R2 adjusted=95.59% indicating excellent fit of the data to the model. A maximum yield of 20.1% (organic) + 20.62% (aqueous) by weight of bio–oil obtained at a pyrolysis temperature 575 °C, retention time 45 min and N2 flow rate 0.5 l/min. The Fourier transform infrared analysis study represents a reduction in the quantities of O–H (hydroxyl), CH (alkanes), CO (esters), CH (alkenes), and CO (primary alcohol) groups, under algal biomass at the expanding pyrolysis temperatures. The gas chromatography–mass spectroscopy investigation showed highest concentrations of 4–Methylpentanamide, n–Heptadecane, 2–Methyl naphthalene and n–Hexadecanoic acids in bio–oil.

Tomato waste biochar in the framework of circular economy

Tomato pomace was slowly pyrolyzed at 350 and 550 °C (under an N2 flow of 50 L/h) at a rate of 6 °C/min and a residence time of 1:30 h to produce two biochars named B350 and B550, respectively. In addition, the two biochars were chemically activated with ΚΟΗ (at a ratio of 1:10 w/v) at 800 °C to produce two new materials named BA350 and BA550. The four biochars produced were characterized physically and chemically (pH, yield, calorific value). They were also analyzed by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (B.E.T), elemental analysis (EA), and thermogravimetric analysis (TGA). The results showed that as the pyrolysis temperature increased (350 to 550 °C), the specific surface area (SSA) increased. The latter was also significantly increased by the activation process. EA showed a variation in the mineral content of the produced biochars, resulting in a different content of the biochars after activation. The parameters studied showed that biochars from tomato waste could be used as an organic amendment to improve soil fertility in agricultural. In addition, because of their ability to absorb water, they could be used as a water reservoir in soils in arid areas.

Low-Temperature Direct Synthesis of Multilayered h-BN without Catalysts by Inductively Coupled Plasma-Enhanced Chemical Vapor Deposition.

Low-temperature direct synthesis of thick multilayered hexagonal-boron nitride (h-BN) on semiconducting and insulating substrates is required to produce high-performance electronic devices based on two-dimensional (2D) materials. In this study, multilayered h-BN with a thickness exceeding 5 nm was directly synthesized on quartz and Si at low temperatures, between 400 and 500 °C, by inductively coupled plasma-enhanced chemical vapor deposition using borazine as the precursor material. The quality and thickness of the h-BN crystals were investigated with respect to synthesis parameters, namely, temperature, radio frequency power, N2 flow rate, and H2 flow rate. Introducing N2 and H2 carrier gases critically affected the deposition rate, and increasing the carrier gas flow rate enhanced the h-BN crystal quality. The typical optical band gap of synthesized h-BN was approximately 5.8 eV, consistent with that of previous studies. The full width at half-maximum of the h-BN Raman peak was 32-33 cm-1, comparable to that of commercially available multilayered h-BN on Cu foil. These results are expected to facilitate the development of 2D materials for electronics applications.

Study on the preparation mechanism of novel WC-Cr2(C, N)-Co nanocomposites

In this work, the WC-Cr2(C, N)-Co nanocomposites were synthesized by using the one-pot carbothermal reduction nitridation hydrothermal precursor method. The preparation mechanisms, including phase and morphology evolutions, were investigated by differential thermal analysis (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and thermodynamic analysis. The results showed that phase evolution, with temperature increasing, follows the sequences of (amorphous phase, WO2.72) → (CoWO4, WO2.72, WO2, CrWO3) → (WO2, CoWO4, Co6W6C, CrWO3) → (W2C, Co3W3C, WC) → (WC, W2C, Co3W3C) → (WC, Co, Co3W3C trace amount). Through comparing different heat treatment conditions, the powder particle size was more easily affected by temperature than holding time. The higher temperatures or longer time holding resulted in the aggregation of powder particles. Finally, WC-Cr2(C, N)-Co nanopowders with about 60 nm were obtained at 1050 °C for 1 h under the N2 flow of 1 L/min with the oxygen content of 0.22 wt% and the free carbon content of 0.19 wt%. The TEM elements mapping revealed that Cr distributes uniformly with WC grains, Co and WC grains are combined well. The surface of WC-Cr2(C, N)-Co determined by XPS is mainly composed of W, Co, Cr, C, N, and O. The spark plasma sintering (SPS) sintered WC-Cr2(C, N)-Co composite shows a nanocrystalline microstructure with the average grain size ∼170 nm, and the excellent comprehensive mechanical properties with the Vickers hardness 1730 Kg·mm−2 and fracture toughness 11.5 MPa·m1/2, respectively.

Microstructure, mechanical properties, and corrosion resistance of TiSiN coating prepared by FCVA technique with different N2 flow rates

TiSiN coatings have attracted extensive attention due to excellent performance in cutting tools, Marine engineering equipment and ship critical components. However, due to the many microparticles and micropores on the coating surface prepared by traditional PVD techniques, the performance of the coatings, especially corrosion resistance, is seriously affected. Therefore, the preparation of high quality TiSiN coatings is very important for the industrial applications. In this study, high-quality TiSiN coatings were prepared by FCVA technique. The effect of N2 flow rate on microstructure, mechanical properties and corrosion resistance of TiSiN coating was investigated. The results showed that all TiSiN coatings presented smooth and compact microstructure without cracks. Meanwhile, TiSiN coatings had a nanocomposite structure of amorphous Si3N4 encapsulated TiN crystallites and possessed a preferred orientation of TiN (200) plane. With the increase of N2 flow rate, the grain size and hardness increased first and then decreased. When N2 flow rate is 20 sccm, the hardness of TiSiN coating reached the maximum owing to the fine grain strengthening effect. Moreover, TiSiN coating deposited N2 flow rate of 40 sccm had the best corrosion resistance, with the highest charge transfer resistance and pore resistance, which was primarily related to the best surface quality.

In search of the bottlenecks of ammonia synthesis over Ru/Vulcan under ambient conditions.

Hydrogenation of the N-N bond under ambient conditions over 1 wt% Ru/Vulcan was monitored through operando Diffuse Reflectance Infrared Spectroscopy (DRIFTS) and DFT. IR signals centered at 3017 cm-1 and 1302 cm-1 were visible with attributes similar to the asymmetric stretching and bending vibrations of gas phase ammonia at 3381 cm-1 and 1650 cm-1. The intensities of the signals increased with consecutive H2 : Ar and N2 flow cycles at room temperature and atmospheric pressure due to accumulation of the formed NHX on the catalyst surface. DFT estimations revealed that a compound with a molecular stoichiometry of N-NH3 can give rise to an IR signal centered at 3051.9 cm-1. The results of this study, combined with the known vapor liquid phase behavior of ammonia, suggest that under subcritical conditions, the bottlenecks of ammonia synthesis are both N-N bond dissociation and ammonia desorption from the pores of the catalyst.