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Acetic acid (AA), a vital compound in chemical production and materials manufacturing, is conventionally synthesized by starting with coal or methane through multiple steps including high‐temperature transformations. Here we present a new synthesis of AA from ethane through photocatalytic selective oxidation of ethane by H2O2 at 0–25 °C. The catalyst designed for this process comprises g‐C3N4 with anchored Pd1 single‐atom sites. In situ studies and computational simulation suggest the immobilized Pd1 atom becomes positively charged under photocatalytic condition. Under photoirradiation, the holes on the Pd1 single‐atom of OH−Pd1⊕ ${{}^{\oplus }}$ /g‐C3N4 serves as a catalytic site for activating a C−H instead of C−C of C2H6 with a low activation barrier of 0.14 eV, through a concerted mechanism. Remarkably, the selectivity for synthesizing AA reaches 98.7 %, achieved under atmospheric pressure of ethane at 0 °C. By integrating photocatalysis with thermal catalysis, we introduce a highly selective, environmentally friendly, energy‐efficient synthetic route for AA, starting from ethane, presenting a promising alternative for AA synthesis. This integration of photocatalysis in low‐temperature oxidation demonstrates a new route of selective oxidation of light alkanes. [ABSTRACT FROM AUTHOR]

The shale gas revolution bolsters ethane supply, thereby enhancing the economic viability of ethylene production from ethane. Presently, catalytic ethane dehydrogenation technology exhibits immense potential in the realm of ethylene production. This study achieves the electrochemical oxidative dehydrogenation conversion of ethane to ethylene via a solid oxide electrolysis cell (SOEC), effectively circumventing the issue of excessive oxidation during the ethane oxidative dehydrogenation process. An active electrode with an in situ grown metal-oxide interface significantly promotes the activation of the ethane C–H bond, leading to efficient ethylene production. Under the co-electrolysis mode of ethane with CO 2 , the Co@CeO 2 electrode demonstrates exceptional performance, achieving an ethane conversion rate of 33.1% and an ethylene selectivity of 88.9% at an applied voltage of 1.0 V. Moreover, the metal-oxide interface constructed via an in situ exsolved method effectively prevents the agglomeration of nanoparticles at high temperatures, thus enhancing the catalyst's resistance to coking and stability. Notably, the electrode's performance does not exhibit significant degradation even after 100 h of electrochemical reaction. • The electrochemical oxidative dehydrogenation of ethane effectively inhibited excessive oxidation. • The in situ grown metal-oxide interface has stability and promotes the activation of the ethane C–H bond. [ABSTRACT FROM AUTHOR]

The urgency to mitigate environmental impacts from anthropogenic CO2 emissions has propelled extensive research efforts on CO2 reduction. The current work reports a novel approach involving transforming CO2 and ethane into carbon nanotubes (CNTs) using earth‐abundant metals (Fe, Co, Ni) at 750 °C. This route facilitates long‐term carbon storage via generating high‐value CNTs and produces valuable syngas with adjustable H2/CO ratios as byproducts. Without CO2, direct pyrolysis of ethane undergoes rapid deactivation. The participation of CO2 not only enhances the durability of the catalyst, but also contributes about 30 % of the CNTs production, presenting a viable solution to CO2 challenges. The CNT morphology depends on the catalyst used. Co‐ and Ni‐based catalysts produce CNT with a 20 nm diameter and micrometer length, whereas Fe‐based catalysts yield bamboo‐like structures. This work represents a pioneering effort in utilizing CO2 and ethane for CNT production with potential environmental and economic benefits. [ABSTRACT FROM AUTHOR]

Chromium and molybdenum incorporated MgO and MgO–C catalysts were synthesized for hydrogen production from a non-oxidative ethane dehydration reaction. Hydrogen production studies were carried out using a microwave-heated reactor system. The study investigated the effects of reaction temperature, type of active metal, and catalyst preparation method (physical mixture or core–shell structure) on hydrogen selectivity and ethane conversion during dehydrogenation reactions. The results showed that the optimal reaction temperature for the non-oxidative ethane dehydration reaction was 450 °C. Above this temperature, the selectivity of undesired byproducts increased. Catalysts containing molybdenum exhibited higher ethane conversion. Moreover, a comparison of MgO–C-supported catalysts with MgO-supported catalysts revealed that the core–shell catalysts exhibited superior ethane conversion. Notably, the 5Mo@MgO–C catalyst demonstrated exceptional catalytic activity, achieving a high ethane conversion rate of 72% along with excellent stability. [ABSTRACT FROM AUTHOR]

Biodegradation of 1,4-Dioxane at environmentally relevant concentrations usually requires the addition of a primary electron-donor substrate to sustain biomass growth. Ethane is a promising substrate, since it is available as a degradation product of 1,4-Dioxane's common co-contaminants. This study reports kinetic parameters for ethane biodegradation and co-oxidations of ethane and 1,4-Dioxane. Based on experiments combined with mathematical modeling, we found that ethane promoted 1,4-Dioxane biodegradation when the initial mass ratio of ethane:1,4-Dioxane was < 9:1 mg COD/mg COD, while it inhibited 1,4-Dioxane degradation when the ratio was > 9:1. A model-independent estimator was used for kinetic-parameter estimation, and all parameter values for 1,4-Dioxane were consistent with literature-reported ranges. Estimated parameters support competitive inhibition between ethane as the primary substrate and 1,4-Dioxane as the secondary substrate. The results also support that bacteria that co-oxidize ethane and 1,4-Dioxane had a competitive advantage over bacteria that can use only one of the two substrates. The minimum concentration of ethane to sustain ethane-oxidizing bacteria and ethane and 1,4-Dioxane-co-oxidizing bacteria was 0.09 mg COD/L, which is approximately 20-fold lower than the minimum concentration reported for propane, another common substrate used to promote 1,4-Dioxane biodegradation. The minimum 1,4-Dioxane concentration required to sustain steady-state biomass with 1,4-Dioxane as the sole primary substrate was 1.3 mg COD/L. As 1,4-Dioxane concentrations at most groundwater sites are less than 0.18 mg COD/L, providing ethane as a primary substrate is vital to support biomass growth and consequently enable 1,4-Dioxane bioremediation. [ABSTRACT FROM AUTHOR]

The efficient conversion of ethane has attracted more and more attention because of the shale gas revolution. The coupling of ethane dehydrogenation (EDH) and benzene alkylation over the 1.5Pt/HZSM-5 realize high activity close to the thermodynamic equilibrium of EDH at 500 ℃ and 0.9 bar ethane partial pressure. Meanwhile, the coupled reaction shows long-term stability during 22 h with a slightly decreased ethane conversion of 0.03% per hour and as high as 42% selectivity of ethylbenzene. Based on various characterization, including XRD, HR-TEM, NH3-TPD, Py-IR, TGA, it is confirmed that the coupling reaction could convert ethylene, formed by EDH over Pt sites, to ethylbenzene via benzene alkylation over Brönsted acidic sites (BAS) subsequently, and suppressing the sintering of Pt species and coke deposition induced by aromatization and deep dehydrogenation, resulting in high activity and long-time steady state. [ABSTRACT FROM AUTHOR]

A pair of simulated left and right circularly polarized ultra‐fast laser pulses of duration 20 femtoseconds that induce a mixture of excited states are applied to ethane. The response of the electron dynamics is investigated within the next generation quantum theory of atoms in molecules (NG‐QTAIM) using third‐generation eigenvector‐trajectories which are introduced in this work. This enables an analysis of the mechanical and chiral properties of the electron dynamics of ethane without needing to subject the C‐C bond to external torsions as was the case for second‐generation eigenvector‐trajectories. The mechanical properties, in particular, the bond‐flexing and bond‐torsion were found to increase depending on the plane of the applied laser pulses. The bond‐flexing and bond‐torsion, depending on the plane of polarization, increases or decreases after the laser pulses are switched off. This is explainable in terms of directionally‐dependent effects of the long‐lasting superpositions of excited states. The chiral properties correspond to the ethane molecule being classified as formally achiral consistent with previous NG‐QTAIM investigations. Future planned investigations using ultra‐fast circularly polarized lasers are briefly discussed. [ABSTRACT FROM AUTHOR]

New polymeric pipes have been used to overcome difficulties created by metal pipes in gas transmission lines such as corrosion and leakage. In this work, diffusion and solubility cells are designed to determine the diffusivity and possible leakage of methane and ethane gases in the glass-reinforced epoxy (GRE) composite. A composite sample with a diameter of 5.95 mm and thickness of 1.40 mm to determine the diffusivity and a composite powder to estimate the gas solubility are used. The experiments are done under temperatures varied from 25 to 40 ℃ and a pressure of 20 bar. The results show that the diffusivity of both gases increases with increasing temperature; while gas solubility decreases. The highest diffusion coefficient of methane and ethane are observed at 8.23 × 10−11 and 7.94 × 10−11 m2/s at 40 ℃, respectively. Moreover, novel correlations for estimating gas diffusion coefficient and mass flow rate in terms of temperature are developed based on the experimental data with the correlation coefficients (R2) of 0.98 and 1 and the average relative error percent (AREP) less than 4.5% and 0.5%, respectively. Interestingly, CFD (Computational fluid dynamics) results show a good consistency with experimental data for gas concentration profiles through the composite with AREP ranges of 1.95–15.78%. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Composite materials HKUST-1@MCM-41 and HKUST-1@ BPS based on metal–organic framework HKUST-1 [Cu 3 (btc) 2 , btc = benzene-1,3,5-tricarboxylate] and silicas, i.e. , mesoporous MCM-41 and biporous BPS with a bimodal mesopore size distribution, were prepared by one-step direct growth technique. Methane and ethane adsorption isotherms were measured for the HKUST-1@MCM-41 and HKUST-1@BPS composites in a wide pressure range for the first time. The silica porous structure significantly affects the content and location of HKUST-1 crystallites in these host matrices, and thereby the adsorption selectivities of the composites. [ABSTRACT FROM AUTHOR]

Ethylene production has a negative environmental impact, with its separation step being one of the major contributors of pollution. This has encouraged the search for energy-efficient alternatives, among which the adsorptive separation of ethane and ethylene stands out. ZIF-8 is a molecular sieve that is potentially useful for this purpose. It is selective to ethane, an exceptional property that remains unexplained. Furthermore, the adsorption of ethane and ethylene above room temperature, such as at steam cracking process outlet temperatures, has not been addressed either. This work aims to fill this knowledge gap by combining experiments at very low volumetric fillings with density–functional theory modelling methods. Adsorption isotherms of ethane and ethylene on ZIF-8 at pressures below 0.3 bar and 311 K, 333 K, and 363 K were measured using zero-length column chromatography. The low-pressure domain of the isotherms contains information on the interactions between the adsorbate molecules and the adsorbent. This favors the understanding of their macroscopic behavior from simulations at the atomic level. The isosteric enthalpy of adsorption of ethane remained constant at approximately −10 kJ/mol. In contrast, the isosteric enthalpy of adsorption of ethylene decreased from −4 kJ/mol to values akin to those of ethane as temperature increased. ZIF-8 selectivity to ethane, estimated from ideal adsorbed solution theory, decreased from 2.8 to 2.0 with increasing pressure up to 0.19 bar. Quantum mechanical modelling suggested that ethylene had minimal interactions with ZIF-8, while ethane formed hydrogen bonds with nitrogen atoms within its structure. The findings of this research are a platform for designing new systems for the adsorptive separation of ethane and ethylene and thus, reducing the environmental impact of ethylene production. [ABSTRACT FROM AUTHOR]

Grand Canonical Monte Carlo (GCMC) simulation and Molecular Dynamics (MD) simulations were used to study the effects of temperature (310 K to 400 K), pressure (≤30 MPa) and water content (0 molecule/nm3 to 9 molecule/nm3) on the adsorption and diffusion behavior of CH4 and C2H6 in 3 nm kaolinite slit under supercritical conditions. The obtained adsorption capacity, isosteric adsorption heat, concentration distribution and diffusion coefficient were analyzed and compared. The simulation results show that the adsorption capacity of C2H6 is higher under low pressure conditions, and the adsorption capacity of CH4 is higher under high pressure conditions due to the small molecular radius and increased adsorption space. The addition of water molecules and the increase in temperature will reduce the adsorption capacity and isosteric adsorption heat of the two gases. We analyzed the changes in Langmuir volume and Langmuir pressure of the two gases under different temperature and water content conditions. The addition of water molecules and the increase in temperature will reduce the saturation adsorption capacity (which has a greater effect on C2H6) and the adsorption rate of the two gases in the kaolinite slit. The water molecules occupy the adsorption site of the gas molecules (limiting the diffusion of the gas molecules), which reduces the interaction between gas molecules and the wall surface, thus altering the distribution of the two gases in the slit. The increase in temperature will accelerate the oscillation of the gas molecules, increasing diffusion, and also leads to a reduction in the peak value of the adsorption peaks of the two gases. [ABSTRACT FROM AUTHOR]

Co/TiO2 catalysts with different cobalt loadings (3.8, 7.5 and 15 wt%) were prepared by impregnation method of Co(NO3)2 6H2O over titania. Samples containing Co(NO3)2·6H2O and TiO2 in stoichiometric proportions in order to obtain CoTiO3 and Co2 TiO4 phases were also synthesized. The effect of the calcination treatment at two different temperatures, 550 and 1150 °C, was investigated. Characterizations by several techniques, such as XRD, UV–vis–NIR, DRS, Raman and XPS, were carried out. XRD showed the coexistence of three phases: CoTiO3; Co2TiO4 and Co3O4 after calcination at 550 °C, while calcination at high temperature (1150 °C) led to single-phase systems (CoTiO3 or Co2TiO4). Diffuse reflection and XPS spectroscopy showed that divalent cobalt occupies octahedral sites in the ilmenite phase, and both tetrahedral and octahedral sites in the spinel phase. The catalytic performances of the prepared catalysts were evaluated in the oxidative dehydrogenation reaction (ODH) of ethane to ethylene, as a function of the Co content for Co/TiO2 catalysts and as a function of the calcination temperatures for the CoTiO3 and Co2TiO4 phases. Co(7.5)/TiO2 was the most active, although the conversion of ethane decreased in the first 150 min of the reaction, reaching values comparable to those of Co2TiO4 and CoTiO3; however, Co(7.5)/TiO2 was confirmed as having the best selectivity to ethylene in comparison with the bulk phases, CoTiO3 and Co2TiO4. The influence of the reaction mixture composition, specifically the presence of water, at different percentages, was investigated. There is a decrease in the overall ethane conversion and an increase in the ethylene selectivity when the percentage of water increases. This behavior can likely be attributed to an increase in the surface concentration of hydroxyl species (OH), resulting in heightened surface acidity. [ABSTRACT FROM AUTHOR]

Equilibrium molecular dynamics (EMD) simulations are used to model density ρL, dynamic viscosity ηL, and self-diffusivity Dself of liquid ethane at pressures close to saturation conditions and temperatures T between (184–298) K, close to the critical temperature Tc. To correct for a T-dependent drift of the simulated results from experimental data, a T-dependent force field modification from our previous studies is extended to a wider T-range. The modification is validated within this work by comparing predicted ρL, ηL, and Dself to experimental reference data. With the modification applied, EMD simulations are able to predict ρL, ηL, and Dself of liquid ethane at T = 298 K with relative deviations of 6.3%, 13%, and 28% from literature references, respectively. Simulations of binary mixtures of liquid ethane with different dissolved gases were performed to predict the Fick diffusivity D11. At a mole fraction of dissolved nitrogen xN2 = 0.03, a deviation of more than a factor of three is found between simulation results and experimental results determined using the dynamic light scattering method. This shows that EMD simulations are not able to predict the critical slowing down of D11 approaching Tc, despite excellent agreement between simulations and reference data for neat ethane. [ABSTRACT FROM AUTHOR]

Photo‐driven CH4 conversion to multi‐carbon products and H2 is attractive but challenging, and the development of efficient catalytic systems is critical. Herein, we construct a solar‐energy‐driven redox cycle for combining CH4 conversion and H2 production using iron ions. A photo‐driven iron‐induced reaction system was developed, which is efficient at selective coupling of CH4 as well as conversion of benzene and cyclohexane under mild conditions. For CH4 conversion, 94 % C2 selectivity and a C2H6 formation rate of 8.4 μmol h−1 is achieved. Mechanistic studies reveal that CH4 coupling is induced by hydroxyl radical, which is generated by photo‐driven intermolecular charge migration of an Fe3+ complex. The delicate coordination structure of the [Fe(H2O)5OH]2+ complex ensures selective C−H bond activation and C−C coupling of CH4. The produced Fe2+ can be used to reduce the potential for electrolytic H2 production, and then turns back into Fe3+, forming an energy‐saving and sustainable recyclable system. [ABSTRACT FROM AUTHOR]

It is predictable that hydrogen gas will be used as the common main energy supply instead of fossil fuels in the near future. Studying hydrogen-production by using hydrogen-rich materials as a source of hydrogen on metal-free catalysts may be worthwhile. We studied the adsorption of ethane, as a hydrogen-rich molecule, on the one, two and three aluminum-doped boron nitride nanotubes using density functional theory. The interactions between any possible sides of ethane and any possible sites on Al B -doped BNNT were studied. The only adsorption has occurred from the carbon atom side of the ethane molecule on the doped aluminum atom site of the BNNT. After the adsorption process, the possible configurations of the intermediates and transition states to receive the decomposition reaction pathway of the ethane molecule were surveyed. The results showed that the ethane molecule was decomposed only on the two aluminum-doped BNNT to four hydrogen atoms. Ethane molecule could be adsorbed from its carbon atom on aluminum-doped BNNT and the adsorption process is exothermic. Also, the structure where two boron atoms in one honeycomb of boron nitride nanotube were replaced with two aluminum atoms has suitable activity and could decompose the ethane molecule into four adsorbed hydrogen atoms and acetylene molecule. Thus, the aluminum atoms could improve the performance of the boron nitride nanotube as a catalyst. [ABSTRACT FROM AUTHOR]

Ethylene (C2H4) is a major chemical for the modern society, and new technologies for its production are of strategic importance globally. Recently, oxidative dehydrogenation of ethane (C2H6) using CO2 as a milder oxidant (CO2‐ODH) is proposed as a potential way for C2H4 production, and development of effective catalysts for the process is drawing wide attention. Here, we report on a facilely prepared ZSM‐5 supported Zn system, i. e., ZnZSM‐5, which showed great promise in CO2‐ODH. Samples with different Zn loadings were prepared and evaluated, and the highest performance was obtained over 0.05ZnZSM‐5 at 700 °C and a CO2:C2H6 feeding ratio of 5 : 1. During 340 min TOS, the C2H6 conversion decreased moderately from 36.2 % to 23.1 %, and the C2H4 yield stabilized at 21.9 % to 27.9 %. Based on systematic characterization and investigation of reaction conditions, the structure‐performance relationship and reaction network were discussed in detail. [ABSTRACT FROM AUTHOR]

Ethylene (C2H4) is a major chemical for the modern society, and new technologies for its production are of strategic importance globally. Recently, oxidative dehydrogenation of ethane (C2H6) using CO2 as a milder oxidant (CO2‐ODH) is proposed as a potential way for C2H4 production, and development of effective catalysts for the process is drawing wide attention. Here, we report on a facilely prepared ZSM‐5 supported Zn system, i. e., ZnZSM‐5, which showed great promise in CO2‐ODH. Samples with different Zn loadings were prepared and evaluated, and the highest performance was obtained over 0.05ZnZSM‐5 at 700 °C and a CO2:C2H6 feeding ratio of 5 : 1. During 340 min TOS, the C2H6 conversion decreased moderately from 36.2 % to 23.1 %, and the C2H4 yield stabilized at 21.9 % to 27.9 %. Based on systematic characterization and investigation of reaction conditions, the structure‐performance relationship and reaction network were discussed in detail. [ABSTRACT FROM AUTHOR]

Methane is the fundamental raw material of the C1 chemical industry, with abundant reserves. Its direct conversion into high-value-added chemicals has great scientific significance and broad commercial potential for the efficient use of methane resources. However, it is difficult to convert methane into more useful hydrocarbons and hydrogen, as the reaction usually requires external energy to overcome thermodynamic limitations. Non-oxidative coupling of methane to produce ethane and hydrogen is a promising supply technology. Catalysts which can be adapted to various energy sources are key to this technology. In recent years, considerable progress has been made in the design and application of these thermal and photocatalysts. This review outlines some typical catalysts, and reviews the progress in the understanding of reaction mechanisms. Finally, suggestions for the development of high-selectivity and high-stability catalysts for the future are presented. [ABSTRACT FROM AUTHOR]

Hydrate–liquid–vapour (HLV) equilibrium of aqueous clathrates formed from gas mixtures can be complex compared to hydrates formed with single guests. Typically, pressure and temperature are controlled to obtain these data, but for multicomponent systems, it is necessary to control/report more intensive variables, namely, composition. Metastability, manifested as impractically long experimental times, has been reported to be a challenge with some multicomponent systems. We present HLV equilibrium conditions of two ternary gas mixtures: methane + ethane + propane (90:7:3 molar ratio) and methane + propane + carbon dioxide (55:5:40 molar ratio). Conditions varied in the temperature range of 275–285 K and the pressure range of 1.24–4.75 MPa. Experimental standard uncertainties were on average 0.10 K and 0.005 MPa for methane + ethane + propane and 0.19 K and 0.005 MPa for methane + propane + carbon dioxide. Our technique allowed us to bypass the limitations reported in the literature and provided fast, reproducible HLV equilibria for gas‐dominated systems. [ABSTRACT FROM AUTHOR]

As a novel reaction mode of oxidative dehydrogenation of ethane to ethylene, the chemical looping oxidative dehydrogenation (CL-ODH) of ethane to ethylene has attracted much attention. Instead of using gaseous oxygen, CL-ODH uses lattice oxygen in an oxygen carrier or redox catalyst to facilitate the ODH reaction. In this paper, a perovskite type redox catalyst LaMnO3+δ was used as a substrate, Ce3+ with different proportions was introduced into its A site, and its CL-ODH reaction performance for ethane was studied. The results showed that the ratio of Mn4+/Mn3+ on the surface of Ce-modified samples decreased significantly, and the lattice oxygen species in the bulk phase increased; these were the main reasons for improving ethylene selectivity. La0.7Ce0.3MnO3 showed the best performance during the ODH reaction and showed good stability in twenty redox cycle tests. [ABSTRACT FROM AUTHOR]

In search of a more effective process of ethane oxidative hydrogenation, different operation modes (thermal and microwave heating) are compared. The catalyst Mo1-V0.3-Te0.13-Nb0.11-Ox was prepared by hydrothermal synthesis and characterized by a set of physicochemical methods (XRD, N2 adsorption, SEM, EDX). The direct microwave heating of the catalyst layer is proposed as an alternative way of energy-saving ethane-to-ethylene oxidation by a Mo-V-Te-Nb-Ox system. A substantial decrease in the reactor temperature upon the microwave-assisted process is accompanied by extremely high catalyst selectivity, which remains at a very high level of 98+%. [ABSTRACT FROM AUTHOR]

Clarifying alkane gas condensation characteristics is crucial to designing and optimizing liquefaction heat exchangers, which imposes higher demands on the microscopic understanding of alkane heterogeneous condensation. Thus, in this study, the condensation process of methane nucleation under different driving forces is investigated by molecular dynamics (MD) simulations. The dynamics characteristics of nucleation in methane heterogeneous condensation are analyzed by varying initial gas-phase pressure, cold wall temperature, and ethane content. The results showed that increasing the initial gas-phase pressure enhances intermolecular interactions, which alter the cluster formation path and significantly increase the methane gas nucleation rate from 1.997 × 1033/(m3·s) to 1.068 × 1034/(m3·s). While lowering the cold wall temperature promotes condensation by weakening the thermal motion of the gas molecules. Once condensation nuclei form in the system, the lower temperature conditions from lowering the cold wall temperature result in a higher growth rate of the clusters. Additionally, the addition of easily condensable component ethane can improve the condensation nucleation characteristics of low-saturated methane gas, facilitating the liquefaction of methane. This study aims to provide a microscopic understanding of the advancement of gas liquefaction technology by investigating the heterogeneous nucleation of alkane under different conditions from a microscopic perspective. • Effects of pressure and temperature on methane condensation are analyzed. • Mechanism of ethane promoting low-saturation methane condensation is investigated. • Mechanisms of different driving forces on condensation nucleation are studied. [ABSTRACT FROM AUTHOR]

The effect of the CO 2 :C 2 H 6 feed ratio, the relative Lewis acidity of reducible and unreducible catalytically active metal oxide supports with and without Fe 3 Ni 1 alloy nanoparticles on the activity, selectivity and stability for the CO 2 -mediated oxidative dehydrogenation of ethane (CO 2 -ODHE) is investigated. To circumvent the influence of the typically dissimilar textural properties of the supports in bulk form, overlayer oxide supports of V, Cr, Ga, Ti or Sm coated on a common γ-Al 2 O 3 carrier were employed. Separately, (Ni 0.75 Fe 0.25)Fe 2 O 4 precursor nanoparticles were synthesized via a nonaqueous surfactant-free method, sonication-deposited onto supports and reduced in situ into an Fe 3 Ni 1 alloy microstructure of bcc and fcc mixed phases captured with in situ XRD. When exposed to carbon dioxide at 255 °C, a selective re-oxidation of the bcc phase via CO 2 dissociation is observed, while the fcc phase stays stable and only partially re-oxidizes above 525 °C. Upon exposure to CO 2 -ODHE conditions, the initial activity of the bare supports increases with increasing acid site strength, but this activity is rapidly lost in case of the strongly acidic supports. Comparison of the C 2 H 4 and CO selectivity indicate direct dehydrogenation is preferred over the oxidative dehydrogenation pathway and is initially occurring in combination with some CO-forming routes, possibly the dry reforming of C 2 H 6. This CO forming route is significant over the most acidic and reducible VO x @Al 2 O 3 support in the early stages of operation. The addition of the Fe 3 Ni alloy increases the conversions of both C 2 H 6 and CO 2 across all supports, with a notably stronger effect observed on CO 2 conversion especially over the highly acidic and reducible VO x @Al 2 O 3 and CrO x @Al 2 O 3. As a result, the CO selectivity is increased due to ethane dry reforming activity over the latter supports while CO 2 -ODHE activity is observed over the supports with intermediate and weak acid sites. [Display omitted] • The initial activity of bare supports increases with acid site strength but is lost rapidly for strongly acidic supports. • Direct dehydrogenation with dry reforming are dominant initially and increase with the bare support acidity. • Supported catalysts show improved activity with increasing support acidity especially in CO 2 conversion. • Improved activity, especially on strongly acidic supports, results in DRE activity and weakening acidity promotes CO 2 -ODHE. • CO 2 -rich feed improves the catalyst stability and yields owing to promotion of the reverse Boudouard reaction. [ABSTRACT FROM AUTHOR]

Adsorbed natural gas (ANG) is a promising solution for improving the safety and storage capacity of low-pressure gas storage systems. The structural–energetic and adsorption properties of active carbon ACPK, synthesized from cheap peat raw materials, are presented. Calculations of the methane–ethane mixture adsorption on ACPK were performed using the experimental adsorption isotherms of pure components. It is shown that the accumulation of ethane can significantly increase the energy capacity of the ANG storage. Numerical molecular modeling of the methane–ethane mixture adsorption in slit-like model micropores has been carried out. The molecular effects associated with the displacement of ethane by methane molecules and the formation of a molecule layered structure are shown. The integral molecular adsorption isotherm of the mixture according to the molecular modeling adequately corresponds to the ideal adsorbed solution theory (IAST). The cyclic processes of gas charging and discharging from the ANG storage based on the ACPK are simulated in three modes: adiabatic, isothermal, and thermocontrolled. The adiabatic mode leads to a loss of 27–33% of energy capacity at 3.5 MPa compared to the isothermal mode, which has a 9.4–19.5% lower energy capacity compared to the thermocontrolled mode, with more efficient desorption of both methane and ethane. [ABSTRACT FROM AUTHOR]

Objective The co-cracking technology of ethane and propane is optimized. Methods The BSPA ethylene cracking evaluation test equipment of KBR company is used to optimize the separate cracking of ethane and propane and the blending cracking technology according to different ratios in the laboratory. Results When the blend proportion of ethane is 20 %- 90 %, t he yields of ethylene, diene and triene are increased. When the blend proportion of ethane is 80%-90%, the highest yields of ethylene, diene and triene are 55. 28 %, 56. 05 % and 58. 01 %, respectively. Conclusion T he optimized result is applied in industrial ethylene cracking plant, the total ethylene yield and the diene yield don't decrease when the proportion of light cracking feedst0ck in t he whole cracking feedstock reduced more than 10%, and the remarkable industrial application effect has been obtained. [ABSTRACT FROM AUTHOR]

Co/Al2O3 catalysts with different Co loadings and different calcination temperatures exhibit totally various catalytic performances for ethane dehydrogenation. At lower loadings, isolated Co2+ species in the framework of CoAl2O4 formed via strong interaction between Co and alumina leads to selective activation of C–H bond and the resulting high selectivity to ethylene. While a higher Co loading with the formation of aggregated metallic Co species through the in-situ reduction of Co3O4 on the catalyst surface results in C–C bond cracking to methane. Moreover, given the results of structural characterization and activity test, the increased calcination temperature enhances the interaction between Co species and alumina and facilitates the formation of CoAl2O4 even at a relatively high Co loading of 5%, contributing to the significant improvement of the catalytic behavior from undesired C–C bond breakage to C–H bond rupture. [ABSTRACT FROM AUTHOR]

Source attribution of natural gas emissions from fossil fuels in New Mexico's San Juan Basin (SJB) is challenging due to source heterogeneity and emissions transience. We demonstrate that ethane (C2H6) to methane (CH4) mixing ratios can identify and separate sources over different scales using various measurement techniques. We report simultaneous CH4 and C2H6 observations near a coal mine vent and oil and gas (O&G) emission sources using ground‐based in situ measurements in 2020/2021. During these campaigns, we observed a stable coal vent C2H6:CH4 ratio of 1.28% ± 0.11%, discernibly different than nearby O&G source ratios ranging from 0.9% to 16.8%. We analyze airborne observations of the SJB taken in 2014/2015 that exhibit similar coal vent ratios and further show the region's heterogeneity. We identify episodic O&G sources, including a gas plant source detected in 2014/2015 that is absent in our 2020/2021 data. We examine total column observations of C2H6 and CH4 made in 2013 with a solar spectrometer and find a C2H6:CH4 ratio of 1.3% ± 0.4% for the coal vent. The stable and unique coal vent ratio relative to other O&G sources in the region is used to demonstrate that consistent attribution is possible using various measurement methods at multiple scales across many years. Finally, we demonstrate that using C2H6 as a proxy for fossil CH4 inversions can inform detailed basin‐scale inversions, provided we understand source specific changes in the C2H6:CH4 ratio like we report in the SJB. Plain Language Summary: Oil, gas, and coal production processes are known to emit methane, a potent greenhouse gas, and other hydrocarbon air pollutants. Attributing these emissions to specific anthropogenic fossil sources is challenging in the vast and variable infrastructure. Ethane is often co‐emitted with methane and the ratio of ethane to methane in emission sources varies significantly with source types. By measuring this ratio with high sensitivity and accuracy, we can "fingerprint" gas sources by their unique ratio. We report simultaneous measurements of ethane and methane, and an empirical analysis of the ratio to demonstrate source specific attribution. Our varied measurement techniques spanning spatial scales (near‐source ground, airborne, and remote sensing) were used to sample sources in New Mexico's San Juan basin over 8 years. Despite a diverse and changing emissions environment, ethane to methane ratios were successfully used to identify and apportion several sources across scales in space and time. Specifically, our measurements show consistent and stable ethane to methane ratios from a large coal vent source in the study region. Our findings inform efforts seeking to characterize and quantify gas emissions in fossil extraction regions using multi‐scale data from diverse instruments. Key Points: Multiple measurement techniques across spatiotemporal scales show consistent and stable ethane:methane ratios from a coal vent shaftEthane:methane ratios are a valuable tool for source apportionment, plume separation, and oil and gas basin emissions characterizationA large gas plant source was identified in 2015 but abated in 2021 showing change with time and monitoring [ABSTRACT FROM AUTHOR]

NiO-based catalysts are among the most active and selective catalytic systems for lowtemperature oxidative dehydrogenation (ODH) of ethane into ethylene and, therefore, they have been extensively studied in the last twenty-five years. This paper reviews the most relevant works focusing on NiO-based catalysts for ethane ODH, including promoted and unpromoted, bulk and supported NiO. The effects of the nature of the promoter and of the support together with the influence of the method of preparation used on their activity in ethane ODH are discussed in detail as they were shown to be key factors controlling the catalytic performance, including the catalyst stability. The reaction mechanism involved in ethane ODH reaction over NiO-based catalysts is also presented and discussed. [ABSTRACT FROM AUTHOR]

In this work, a series of cobalt doped hexagonal mesoporous silica (Co‐HMS) with the different Co content were prepared by direct hydrothermal method and applied to oxidative dehydrogenation (ODH) reaction of ethane with carbon dioxide. Structural and chemical properties of the catalysts were characterized by nitrogen adsorption, X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), electron dispersive spectroscopy (EDS), X‐ray photoelectron spectroscopy (XPS), and Raman and ultraviolet–visible (UV‐vis) spectroscopy. These characterizations showed that cobalt not only entered the framework of Co‐HMS catalysts but also was evenly dispersed in the bulk. The valence state and coordination mode of cobalt played an important role in the whole ODH reaction system of ethane with carbon dioxide. 2% Co‐HMS with dominant Co2+ had the highest conversion of ethane (26.0%). With the different cobalt content in the catalyst, the proportion of Co2+(Td) and Co2+(Oh) is also different. 1% Co‐HMS with more Co2+(Td) performed the highest ethylene selectivity of 86.7%, which was stable during the 10 h reaction time. [ABSTRACT FROM AUTHOR]

Redox conversion of ethane at 600 °C on Mo-containing oxide systems differing in the composition and preparation method was studied. The ethane conversion and the selectivity of the ethylene formation increase in the series of MoO3 samples supported on SiO2 (silica gel), TiO2 (anatase), and alumina. The efficiency of the MoO3/Al2O3 systems increased when HNO3 was added to a (NH4)6Mo7O24 solution used to impregnate the support, and also when γ-Al2O3 was replaced with Al(OH)3. Gallium oxide additives improve the properties of the MoO3/Al2O3 system, increasing the ethane conversion to 44% at ethylene formation selectivity of more than 96%. The systems under consideration are characterized by high stability and retain their activity after five reaction—regeneration cycles. Based on the data obtained during the reaction of ethane with the Mo systems and in the course of regeneration of the reduced samples with oxygen, the content of active oxygen corresponding to the MoO3 ↔ MoO2 transformation was assessed. [ABSTRACT FROM AUTHOR]

The potential of on‐purpose ethylene production, in parallel with CO2 conversion to CO, is of great interest. Iron oxide‐based catalysts supported on mixed oxides zNiO−MgO−ZrO2, z=0–10 wt%, are active for the CO2‐assisted oxidative dehydrogenation of ethane at 873 K and 101.3 kPa. Enhanced control of their selectivity towards C−H bond cleavage and not towards C−C bond cleavage can be achieved by adjusting the Ni/Fe ratio. Fine tuning Ni/Fe molar ratio results in stable catalytic performance, with selectivity towards C2H4 >65 % and C2H6 conversion >20 %. Density functional theory (DFT) calculations show a significant enhancement in activity due to decrease in the oxygen‐vacancy formation energy and the increase in hydrogen adsorption energy at the Ni oxide‐Fe oxide interface. The latter interface is the potential active site responsible for the enhanced performance that was experimentally exemplified for the Fe oxide/zNiO−MgO−ZrO2 catalysts vs Fe oxide/MgO−ZrO2. [ABSTRACT FROM AUTHOR]

[Display omitted] The photocatalytic reduction of carbon dioxide (CO 2) to fossil fuels has attracted widespread attention. However, obtaining the high value-added hydrocarbons, especially C 2+ products, remains a considerable challenge. Herein, gold (Au) nanoparticle-modified bismuth-rich bismuth oxybromide Bi 12 O 17 Br 2 nanotube composites were designed and tested. Au nanoparticles act as electron traps and thermal electron donors that promote the efficient separation and migration of carriers to form the C 2+ product. As a result, compared with the pure Bi 12 O 17 Br 2 nanotubes, Au@Bi 12 O 17 Br 2 composites can not only produce the carbon monoxide (CO) and methane (CH 4), but also covert CO 2 into ethane (C 2 H 6). In this study, Au@Bi 12 O 17 Br 2 -700 was used to obtain a C 2 H 6 production rate of 29.26 μmol h−1 g−1. The selectivities during a 5-hour test reached 94.86% for hydrocarbons and 90.81% for C 2 H 6. The proposed approach could be used to design high-performance photocatalysts to convert CO 2 into high value-added hydrocarbon products. [ABSTRACT FROM AUTHOR]

Summary: Ethane recovery is an important way to increase the economic benefits of unconventional natural gas, such as shale gas. However, current researches did not focus on obtaining high purity and high recovery rate of ethane. In this study, two pure refrigerant cascade natural gas liquefaction processes without (Process 1) or with (Process 2) flash gas recovery are proposed to coproduce high‐purity liquefied ethane gas (LEG) and liquefied natural gas (LNG). The proposed processes are combined with advanced distillation methods to reduce the energy consumption through process and energy integration. Aspen HYSYS V11 and genetic algorithm (GA) are used to simulate proposed processes and optimize the refrigeration cycles, respectively. To search the optimal conditions of distillation column, power consumption under different distillation pressure is comparatively analyzed, and the optimal distillation pressure is about 2.7 MPa. According to the optimization results, the specific power consumption of Process 1 is 0.4384 ~ 0.4584 kWh/Nm3(NG), and that of Process 2 is 0.4336 ~ 0.4503 kWh/Nm3(NG) when ethane content is 10% ~ 40%. Process 2 is preferred for lower power consumption and no material waste. Further study is conducted to research the effect of throttling temperature and ethane content on the system performance of Process 2. In addition, the feasibility exploration of cryogenic compression shows that re‐compression of natural gas after distillation is not energy saving for the proposed process. [ABSTRACT FROM AUTHOR]

The thermal pyrolysis of ethane and propane at a pressure of 1–3 atm was experimentally studied in a through-flow reactor. Kinetic modeling of the process under these conditions showed good agreement with experimental data in terms of both the conversion of alkanes and the yield of pyrolysis products, which allowed us to expand the modeling range of pressure. The results obtained show that the pressure change in the range of 1–15 atm has no noticeable effect on the pyrolysis of light alkanes. On this basis, we concluded that the previously established effect of pressure on the oxidative cracking of ethane was associated with its effect on the oxidative stages of the process. [ABSTRACT FROM AUTHOR]

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Cobalt-exchanged ZSM-5 catalyzes the ammoxidation of ethane (2 C 2 H 6 + 3 O 2 + 2 NH 3 → 2 CH 3 CN + 6 H 2 O), yet the active form of cobalt, the role of the Brønsted acidic zeolite, and the reaction pathways remain elusive. Comparisons of rates and selectivities of reactions at distinctive cobalt sites (Co2+ at Al pair sites (CoZ 2), Co 3 O 4 , cobalt phyllosilicate, and cobalt aluminate) suggest sites that form from CoZ 2 provide the greatest rates and selectivities for CH 3 CN and C 2 H 4 formation. Significantly, we revealed a large fraction of CH 3 CN appears to form directly through a trimolecular reaction at cobalt ions without desorption of intermediates. In parallel, a more conventional sequential pathway dehydrogenates C 2 H 6 , aminates C 2 H 4 , and oxidatively dehydrogenates C 2 H 5 NH 2 to produce CH 3 CN. Combined rate measurements with temperature programmed reactions and in situ infrared spectra demonstrate that O 2 -derived intermediates at cobalt ions initiate both reaction sequences by abstracting H-atom from C 2 H 6. [Display omitted] • Standard synthesis creates different distributions of cobalt species within H-ZSM-5. • ZSM-5 with cobalt ions only at Al pair sites gives greatest rates and selectivities. • O 2 -derived intermediates abstract H-atoms from C 2 H 6 to initiate the reaction. • CH 3 CN forms by a trimolecular primary reaction among C 2 H 6 , NH 3 , and O 2 at cobalt. • A parallel pathway forms CH 3 CN by C 2 H 4 amination and dehydrogenation. [ABSTRACT FROM AUTHOR]

Recent studies have discovered that laminar lifted flames (LLFs) can be stabilized within a triangular stabilization regime (TSR), defined by the parameters of normalized lift-off height and Reynolds number. The stabilization mechanism of an LLF could be explained by using an effective Schmidt number over an extended pressure range. In this study, the existence of LLFs of pure ethane was confirmed for the first time, and their characteristics were investigated. However, the corresponding TSR was significantly shrunk compared to propane and butane. The reasons were discussed in relation to the effective Schmidt number. The variation in effective Schmidt number depending on lift-off height and fuel type was theoretically predicted by considering the relative influence of the volume expansion on flow velocity and fuel concentration. Two additional stabilization modes near the turbulent transition were examined. One is the pathway from LLFs within the TSR to turbulent lifted flames at higher Reynolds numbers, and the criteria for this transition were explained. The other is an additional stabilization mode having much larger lift-off heights near the blowout conditions, and its stabilization mechanism was discussed. [ABSTRACT FROM AUTHOR]

• Bubble departure diameter of methane/ethane mixtures was experimentally studied • Twelve well-known correlations were compared with the experimental data • An improved model was developed considering mass transfer and Marangoni flow • The new model can predict well for experimental data with the deviation of 18.78% Methane and ethane are the main components of liquefied natural gas (LNG) and mixed-refrigerant liquefaction cycles. The pool boiling characteristics and bubble dynamic parameters of methane/ethane mixtures are important for the design and optimization of LNG systems. In this study, visual experiments were carried out to investigate the pool boiling of methane, ethane and their mixtures on a horizontal flat surface. Heat transfer characteristics and bubble departure diameters were acquired at 0.3 MPa for different concentrations of the mixtures. The bubble departure diameter increases with the increase in superheat temperature and dimensionless Jacob number for all concentrations of the mixture. The non-linear variation with concentrations of the bubble departure diameter can be observed due to the effects of mixtures. The bubble departure diameters for mixtures were predicted by twelve existing correlations, with Cole's correlation having the lowest mean absolute relative deviation (MARD) of 46.28%, with only 38.78% points within ±30% deviation. Therefore, a new model for mixtures was developed based on force equilibrium analysis in this study. Marangoni force is taken into account in the proposed model, as well as the effects of mass transfer on the bubble growth rate in mixtures. The MARD of the new model is 18.78%, which is better than all the twelve existing correlations. [ABSTRACT FROM AUTHOR]

Protonic ceramic ethane fuel cells fed by hydrocarbon fuels are demonstrated to be effective energy conversion devices. However, their practical application is impeded by a lack of anode materials combining excellent catalytic activity with good chemical stability and anti‐carbon deposition properties. In this work, in which Sr2Fe1.5Mo0.5O6‐δ (SFM) double perovskite oxide is used as the matrix framework, catalytic activity toward H2 and C2H6 oxidation is systematically investigated using Ba‐doping. It is found that the concentration of the oxygen vacancy is gradually improved with increased Ba content to significantly enhance catalytic activity toward H2 and C2H6 oxidation. From the series studied, Ba0.6Sr1.4Fe1.5Mo0.5O6‐δ exhibits the highest catalytic activity, while the power densities of the electrolyte‐supported Ba0.6SFM/BaCe0.7Zr0.1Y0.2O3‐δ (BCZY)/La0.58Sr0.4Co0.2Fe0.8O3‐δ (LSCF)‐Sm0.2Ce0.8O2‐δ (SDC) single cell reach 205 and 138 mW cm–2 at 750°C in H2 and C2H6, respectively. The ethane conversion rate of the experimental cell is shown to reach 38.4%, while simultaneously maintaining ethylene selectivity at 95%. Furthermore, the single cell exhibits no significant attenuation during stable operation for 20 h, as well as demonstrating excellent anti‐coking performance. The proposed results suggest that Ba0.6Sr1.4Fe1.5Mo0.5O6‐δ represents a promising anode material for efficient hydrocarbon‐related electrochemical conversion to realize the coproduction of ethylene and power in protonic ceramic ethane fuel cells. [ABSTRACT FROM AUTHOR]

A series of the layered double oxides supported molybdenum oxide catalysts were synthesized and evaluated in the oxidative dehydrogenation of ethane with CO2 (CO2-ODHE). The 22.3 wt% Mo/LDO catalyst delivered a 92.3%selectivity to ethylene and a 7.9% ethane conversion at relatively low temperatures. The molybdenum oxide catalysts were fully characterized by XRD, BET, SEM, TEM, UV–vis, Raman TG, and XPS. Isolated [MoO4]2− dominated on the surface of the fresh 12.5 wt% Mo/LDO catalyst. With the increase of the Mo content, the Mo species transformed from [MoO4]2− to [Mo7O24]6− and [Mo8O26]4− on the 22.3 wt% and 30.1 wt% Mo/LDO catalysts, respectively. The redox mechanism was proposed and three Mo species including [MoO4]2−, [Mo7O24]6−, and [Mo8O26]4− showed quite different functions in the CO2-ODHE reaction: [MoO4]2−, with tetrahedral structure, preferred the non-selective pathway; [Mo7O24]6−, with an octahedral construction, promoted the selective pathway; and the existence of [Mo8O26]4− reduced the ability to activate ethane. This work provides detailed insights to further understand the relationship between structure–activity and the role of surface Mo species as well as their aggregation state in CO2-ODHE. [ABSTRACT FROM AUTHOR]

The rapid deactivation caused by coke deposits is the major obstacle to the ethane aromatization of Zn-based catalysts. We have successfully synthesized a Zn-embedded inside HZSM-5 crystal catalyst (Zn@HZSM-5) by hydrothermal synthesis using preformed Zn/SiO2 as the only silicone source. Based on various characterization results, including in situ etching XPS, operando DRIFTS, as well as NMR, it is found that Zn(OH)+ and [Zn–O–Zn]2+ species are active sites for ethane aromatization for zinc-based catalysts, and their dynamic transformation significantly changes reaction performance of ethane dehydrogenation. For the Zn/HZSM-5 catalyst, the existence of a large number of [Zn–O–Zn]2+ species causes higher initial ethane conversion and higher selectivity of aromatics, resulting in a large amount of coke deposits. Moreover, [Zn–O–Zn]2+ species on the Zn/HZSM-5 catalyst fast transit to Zn(OH)+ species and subsequently form the sintered ZnO species, leading to rapid deactivation. For the Zn@HZSM-5 catalyst, the embedded structure contributes to forming more Zn(OH)+ species and delays the transformation of the Zn(OH)+ species to [Zn–O–Zn]2+ species, resulting in slowly increased selectivity of aromatics during the reaction. Therefore, the Zn@HZSM-5 catalyst realizes stable ethane conversion with dynamic selectivity. [ABSTRACT FROM AUTHOR]

Membrane technologies are widely used in various modern technological processes. In the chemical industry, membranes are used to solve several problems from increasing the efficiency of targeted processes to ensuring strict environmental legislation. A special synergistic effect is expected in the field of membrane catalysis when it becomes possible not only to accelerate the main reaction using a catalyst affecting the kinetics of the process but also shift the reaction equilibrium toward the products due to the membrane separation of one or more products from the main reaction volume. This advantage of membrane catalytic technologies is especially in demand for endothermic processes. This mini review is devoted to the dehydrogenation of hydrocarbons exemplified by the production of the high demand monomers ethylene, propylene, and styrene and the dehydrogenation of alcohols exemplified by methanol as a key compound of the C1 chemistry. [ABSTRACT FROM AUTHOR]

The results of an experimental study of the partial oxidation of ethane in the temperature range 773–1023 K and at pressures of 1 and 2 atm in a flow reactor with chromatographic analysis of the gas mixture were presented. Oxygen and nitrogen were used as an oxidizer and carrier gas, respectively. The excess fuel ratio was varied from 7.0 to 15.3. Numerical simulation with a detailed description of the complex kinetics of ethane oxidation was performed. The necessity of taking into account heterogeneous processes on the reactor surface under these conditions was shown and a method for this was proposed. When the detailed gas-phase mechanisms of ethane oxidation are complemented with stages describing heterogeneous processes on the surface of the quartz reactor, the results of numerical modeling are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Oxidative dehydrogenation of ethane to ethylene is an important process in light olefin industry; however, the over‐oxidation of ethane leads to low ethylene selectivity. Here, we report a novel approach to electrochemical oxidative dehydrogenation of ethane in anode in conjunction with CO2 reduction at cathode in a solid oxide electrolyser using a porous single‐crystalline CeO2 electrode at 600 °C. We identify and engineer the flux and chemical states of active oxygen species that evolve from the lattice at anode surface to activate and dehydrogenate ethane to ethylene via the reaction of epoxy species. Active oxygen species (O2−, O22− and O2−) at the anode surface effectively dehydrogenate ethane to ethylene, but O− species tend to induce deep oxidation. We demonstrate exceptionally high ethylene selectivity of 95 % and an ethane conversion of 10 % with a durable operation of 300 h. [ABSTRACT FROM AUTHOR]

Adsorption of fluids in nanoporous materials is important for several applications including gas storage and catalysis. The pore network in natural, as well as engineered, materials can exhibit different degrees of connectivity between pores. While this might have important implications for the sorption of fluids, the effects of pore connectivity are seldom addressed in the studies of fluid sorption. We have carried out Monte Carlo simulations of the sorption of ethane and CO2 in silicalite, a nanoporous material characterized by sub-nanometer pores of different geometries (straight and zigzag channel like pores), with varied degrees of pore connectivity. The variation in pore connectivity is achieved by selectively blocking some pores by loading them with methane molecules that are treated as a part of the rigid nanoporous matrix in the simulations. Normalized to the pore space available for adsorption, the magnitude of sorption increases with a decrease in pore connectivity. The increased adsorption in the systems where pore connections are removed by blocking them is because of additional, albeit weaker, adsorption sites provided by the blocker molecules. By selectively blocking all straight or zigzag channels, we find differences in the absorption behavior of guest molecules in these channels. [ABSTRACT FROM AUTHOR]

The oxidative dehydrogenation of ethane (ODH) assisted by CO2 to produce ethylene is inevitably accompanied by the side reaction of dry reforming (DRE) to produce carbon monoxide. However, the key factor determining the dehydrogenation selectivity is still ambiguous. In this paper, four different NiFe/CeO2 catalysts were synthesized via an impregnation method over four types of CeO2. The dehydrogenation selectivity of the four catalysts ranged from 40 % to 83 %. Temperature‐programmed surface reaction and transient response experiments reveal the existence of two types of oxygen species over NiFe/CeO2 catalysts. FeOx layers exist as an oxygen species supply buffer over CeO2 supports. Weakly electrophilic oxygen species supplied by FeOx overlayers could participate in producing C2H4 while strong electrophilic oxygen species supplied by CeO2 supports could participate in producing CO. The content of weakly electrophilic oxygen species is identified to be a rational descriptor of C2H4 selectivity. [ABSTRACT FROM AUTHOR]

The oxidative dehydrogenation of ethane (ODH) assisted by CO2 to produce ethylene is inevitably accompanied by the side reaction of dry reforming (DRE) to produce carbon monoxide. However, the key factor determining the dehydrogenation selectivity is still ambiguous. In this paper, four different NiFe/CeO2 catalysts were synthesized via an impregnation method over four types of CeO2. The dehydrogenation selectivity of the four catalysts ranged from 40 % to 83 %. Temperature‐programmed surface reaction and transient response experiments reveal the existence of two types of oxygen species over NiFe/CeO2 catalysts. FeOx layers exist as an oxygen species supply buffer over CeO2 supports. Weakly electrophilic oxygen species supplied by FeOx overlayers could participate in producing C2H4 while strong electrophilic oxygen species supplied by CeO2 supports could participate in producing CO. The content of weakly electrophilic oxygen species is identified to be a rational descriptor of C2H4 selectivity. [ABSTRACT FROM AUTHOR]

One of the most active and high-selective catalytic systems for oxidative dehydrogenation of ethane is the MoVNbTeOx catalyst. However, this catalytic system has the low thermal stability and is prone to deactivation at temperatures above 350 °C. At the first time it was proposed to use oxygen ((Tcr = –119 °C, Pcr = 48 atm) and ethane (Tcr = 32 °C, Pcr = 51 atm) in supercritical state in the oxidative dehydrogenation process. Carrying out the process at supercritical conditions (T = 240–300 °C, P = 60–100 atm) leads to high selectivity up to 90% for ethylene under growth conversion of ethane and oxygen. At the same time, it manages to keep M1 phase crystallinity unchanged throughout the experiment (more than 40 h). Dependences of ethylene productivity on pressure (Reaction conditions: T = 280 °C, C2H6:O2:N2 = 31:23:46, 2 g of catalyst, the density of the reagent mixture varies from 0.65 (at 1 atm) to 63.15 kg/m3 (at 100 atm) [ABSTRACT FROM AUTHOR]

An effect of hydrogen additions to the initial mixture on the parameters of the oxidative cracking of propane at atmospheric pressure, temperatures of 500–750°C, reaction time of 2 s, and С3H8/О2 initial ratio ~2 was experimentally investigated. It was shown that small amounts of hydrogen promote the process due to the formation of additional active radicals OH• and H•. Performance of the oxidative cracking of propane in a large excess of hydrogen results in an increase in the yield of methane and ethane, while the yield of ethylene, the target product of the process, decreases. [ABSTRACT FROM AUTHOR]