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The chemical looping oxidative dehydrogenation (CL‐ODH) of ethane represents a highly effective approach for converting ethane into the value‐added product ethylene. This investigation focused on the synthesis of SrMnO3 and its halide ions doped derivatives (SrMnO3Cl and SrMnO3Br) through the sol‐gel method. The performance of these perovskites, employed as oxygen carriers in CL‐ODH of ethane, was explored. The results unveiled several advantageous outcomes arising from the incorporation of halide ions (Cl− and Br−) with larger radius into the oxygen sites of the SrMnO3 perovskite. Halide ions doping notably induced cell volume expansion and enhanced lattice fringe spacing. Furthermore, it contributed to elevated oxygen vacancy concentration, increased Mn4+/Mn3+ molar ratio, and improved oxygen ions mobility within the bulk lattice. Fixed‐bed experiments demonstrated that these redox catalysts, doped with halide ions, exhibited outstanding activity and stability during cycling tests, exhibiting enhanced both ethylene selectivity and yield in CL‐ODH of ethane. In summary, the introduction of halide ions into SrMnO3 emerges as a promising strategy for enhancing the performance of CL‐ODH in ethane conversion for SrMnO3 based oxygen carriers. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The support properties can be tuned through changing the addition amount of Zr. As a result, the formation and stability of Co species can be regulated, then, the relationships between different Co species and reaction pathways have been revealed. [Display omitted] TiO 2 , ZrO 2 and a series of TiO 2 -ZrO 2 (TxZ1, x means the atomic ratio of Ti/Zr = 10, 5, 1, 0.2 and 0.1) composite oxide supports were prepared through co-precipitation, and then 3 wt% Co was loaded through wetness impregnation methods. The obtained 3 wt% Co/TiO 2 (3CT), 3 wt% Co/ZrO 2 (3CZ) and 3 wt% Co/TxZ1 (3CTxZ1) catalysts were evaluated for the oxidative ethane dehydrogenation reaction with CO 2 (CO 2 -ODHE) as a soft oxidant. 3CT1Z1 catalyst exhibits excellent catalytic properties, with C 2 H 4 yield, C 2 H 6 conversion and CO 2 conversion about 24.5 %, 33.8 % and 18.0 % at 650 °C, respectively. X-Ray Diffraction (XRD), in-situ Raman, UV–vis diffuse reflectance spectra (UV–vis DRS), H 2 temperature-programmed reduction (H 2 -TPR), Electron paramagnetic resonance (EPR) and quasi in-situ X-ray Photoelectron Spectroscopy (XPS) have been utilized to thoroughly characterize the investigated catalysts. The results revealed that 3CT1Z1 produced TiZrO 4 solid solution with more metal defect sites and oxygen vacancies (Ov), promoting the formation of Co2+-TiZrO 4 structure. Furthermore, the presence of Ov and Ti3+can facilitate the high dispersion and stabilization of Co2+, as well as suppressing the severe reduction of Co2+, leading to superior ethane oxidative dehydrogenation activity. Besides, less Co0 is beneficial to ODHE reaction, because of its promotion effects for reverse water gas shift reaction; however, more Co0 results in dry reforming reaction (DRE). This work will shed new lights for the design and preparation of highly efficient catalysts for ethylene production. [ABSTRACT FROM AUTHOR]

Ni‐M‐O catalysts have demonstrated superior performance in the oxidative dehydrogenation of ethane (ODHE), but precise control over the content of active oxygen species is necessary to achieve optimal C2H4 selectivity. In this work, highly efficient Ni‐Al‐O catalysts were prepared by a plasma‐assisted strategy, and their catalytic properties were evaluated for ODHE reaction. Characterization results revealed that the working atmospheres (O2, H2 and Ar) can not only change the crystallite size of NiO, but also modulate the reduction properties of Ni‐Al‐O catalysts and the distribution of active oxygen species. Consequently, Ar and O2 plasma pretreatment increased the ODHE performance by increasing active surface oxygen, while H2 plasma‐treated catalyst showed a decrease in the catalytic performance compared to the original Ni‐Al‐O catalyst. Among them, O2‐Ni‐Al‐O exhibited 50.8 % ethane conversion and 70.3 % ethylene selectivity at 500 °C. It was accepted that the change in the ratio of defective oxygen to lattice oxygen (OV/OL) was the internal reason to illustrate its excellent performance. For series Ni‐Al‐O catalysts, C2H6 conversion increased linearly while C2H4 selectivity decreased with an increase in OV/OL value. [ABSTRACT FROM AUTHOR]

[Display omitted] • Relationship between ODH of ethane and electrochemical properties. • Optimal catalyst with Nb in the lattice and on the surface is n -type semiconductor. • Relationship between density of non-stoichiometric oxygen and selectivity to C 2 =. • Relationship between electrochemical properties and selectivity to C 2 =. In the present article, a relationship between the catalytic performance in the oxidative dehydrogenation of ethane (ODHE) for Nb-doped NiO catalysts and their electrochemical properties has been proposed. To do so, highly stable and selective Nb-doped NiO catalysts for the ODHE to ethylene have been synthesized by optimizing synthesis parameters such as the amount of oxalic acid in the synthesis gel and the calcination temperature. These catalysts have been characterized by means of XRD, HRTEM, Raman and UV–vis diffuse reflectance spectroscopies, TPR and XPS. Moreover, Electrochemical Impedance Spectroscopy (EIS), capacitance measurements (Mott-Schottky analysis) and cyclic voltammetries studies were also carried out. Electrochemical characterization indicates changes in the type of semiconductivity: p -type for samples calcined at 350 °C and the sample prepared in the absence of oxalic acid and calcined at 500 °C, to n -type for samples prepared in the presence of oxalic acid in the synthesis gel and calcined at 500 °C. According to the obtained results, the most selective catalysts present a low Nb-incorporation on the NiO lattice with a large amount of tiny Nb 2 O 5 nanoparticles covering NiO crystallites. This work presents, for the first time, a complete electrochemical characterization of Nb-doped NiO catalysts showing a correlation between electrochemical properties and catalytic performance. [ABSTRACT FROM AUTHOR]

Ethylene is mainly produced by steam cracking of naphtha or light alkanes in the current petrochemical industry. However, the high-temperature operation results in high energy demands, high cost of gas separation, and huge CO2 emissions. With the growth of the verified shale gas reserves, oxidative dehydrogenation of ethane (ODHE) becomes a promising process to convert ethane from underutilized shale gas reserves to ethylene at a moderate reaction temperature. Among the catalysts for ODHE, MoVNbTeOx mixed oxide has exhibited superior catalytic performance in terms of ethane conversion, ethylene selectivity, and/or yield. Accordingly, the process design is compact, and the economic evaluation is more favorable in comparison to the mature steam cracking processes. This paper aims to provide a state-of-the-art review on the application of MoVNbTeOx catalysts in the ODHE process, involving the origin of MoVNbTeOx, (post-) treatment of the catalyst, material characterization, reaction mechanism, and evaluation as well as the reactor design, providing a comprehensive overview of M1 MoVNbTeOx catalysts for the oxidative dehydrogenation of ethane, thus contributing to the understanding and development of the ODHE process based on MoVNbTeOx catalysts. [ABSTRACT FROM AUTHOR]

The effect of gadolinium additives on the morphology, phase composition, and catalytic properties of MoVSbNbGdOx/SiO2 catalysts in the oxidative dehydrogenation of ethane to ethylene (ODE) is studied. It is shown that gadolinium concentration has a significant effect on the catalytic properties. At an optimum gadolinium content (Gd/Mo = 0.01–0.015), an increase in catalytic activity and ethylene selectivity is observed: at a temperature of 400°C, the ethylene yield achieves 72%, the ethane conversion is higher than 91%, and the ethylene selectivity is higher than 79%. According to X-ray diffraction analysis and scanning and transmission electron microscopy, the main component of the catalyst is the M1 phase stabilized both in the bulk and on the surface of SiO2 particles. The modification of the catalyst with gadolinium significantly affects the morphology of the M1 phase particles. At an optimum gadolinium content, heat treatment leads to the formation mostly of M1 phase particles with a needle-like morphology and the most developed [001] plane emerging on the surface, which exhibit the maximally high activity in ODE. The M1 phase particles with this morphology are mostly stabilized in the bulk of porous spherical SiO2 particles; therefore, they do not undergo strong agglomeration and sintering. A smaller portion of the M1 phase particles with a plate-like morphology, which exhibit a lower catalytic activity, as well as the M2 phase particles, are stabilized on the outer surface of the SiO2 particles. In the catalyst containing no Gd additives, M1 phase particles with a plate-like morphology are mostly formed; this factor leads to a decrease in the catalyst activity. The synthesized catalyst exhibits a long-term stable on-stream behavior in the reaction medium without a deterioration of the properties. [ABSTRACT FROM AUTHOR]

Boron and nitrogen co-doped carbon nanospheres (B X CN) were fabricated using graphitic carbon nitride (g-C 3 N 4) as the precursor and the nitrogen source, and boric acid as the boron source. They featured high specific surface area and porous structure. Besides, the doping of B brought improved chemical and thermal stability of the material. They were further used as catalysts for the oxidative dehydrogenation of ethane (ODHE) for the first time. The B X CN demonstrated higher conversion of ethane and higher selectivity towards ethylene, compared with other carbon catalysts such as carbon nanotubes reported in literature. An ethane conversion of 15.8% with a selectivity of 56.0% towards ethylene were achieved on B 0 · 1 CN at a reaction temperature of 525 °C. The B 0 · 1 CN showed an excellent stability within 7 h ODHE test at 450 °C. This work offers a new strategy of using heteroatoms co-doped carbon-based catalysts with improved activity for ODHE under lower temperatures. [Display omitted] [ABSTRACT FROM AUTHOR]

The oxidative dehydrogenation of ethane (ODHE) to ethylene is a process with many advantages (such as energy conservation and coke resistance). Herein, flower‐like Ni−Al−O catalysts with hierarchical structure and high surface areas were fabricated through a hydrothermal route and were applied to ODHE using O2 as oxidant. Compared with NiO alone, the Al3+ insertion into NiO matrix not only increases the C2H4 selectivity by 3–4 times, but also prevents the generation of CO2 and CH4 above 500 °C. At 550 °C, all Ni−Al−O catalysts maintain approximately 50 % ethylene selectivity regardless of Al content. The ethylene yield of 29.5 % with C2H4 selectivity 55.7 % over Ni−Al0.8‐O sample can be reached at 500 °C. Moreover, the Ni−Al0.8‐O catalyst presents a good stability and has no loss of activity after 100 h continuous evaluation. The various characterizations were carried out for investigating the nature of as‐prepared Ni−Al−O catalysts with different Al loadings. Experimental results demonstrate that the addition of Al not only affects the structure and texture properties of NiO, but also impacts the reducibility of Ni species and the amount of active oxygen species. It is found that the Al3+ substitution results in: (1) smaller NiO size; (2) larger specific surface area; (3) weaker reducibility and (4) fewer non‐stoichiometric oxygen species. Therefore, the significant improvement of ethylene selectivity is observed in Ni−Alx‐O catalysts. [ABSTRACT FROM AUTHOR]

The oxidative dehydrogenation of ethane in the presence of CO2 was studied on SiO2-supported chromium oxide catalytic systems with different texture characteristics. The highest activity was displayed by the samples deposited on SiO2 with a high specific surface area. On the 5%CrОх/SiO2 catalyst, the ethylene selectivity was ~80% at ~50% conversion of ethane. The results of our physicochemical analysis showed that the catalyst activity depended on the content of Cr(VI) particles, whose formation depended on the nature of support. [ABSTRACT FROM AUTHOR]

Ethylene is mainly produced by steam cracking of naphtha or light alkanes in the current petrochemical industry. However, the high-temperature operation results in high energy demands, high cost of gas separation, and huge CO2 emissions. With the growth of the verified shale gas reserves, oxidative dehydrogenation of ethane (ODHE) becomes a promising process to convert ethane from underutilized shale gas reserves to ethylene at a moderate reaction temperature. Among the catalysts for ODHE, MoVNbTeOx mixed oxide has exhibited superior catalytic performance in terms of ethane conversion, ethylene selectivity, and/or yield. Accordingly, the process design is compact, and the economic evaluation is more favorable in comparison to the mature steam cracking processes. This paper aims to provide a state-of-the-art review on the application of MoVNbTeOx catalysts in the ODHE process, involving the origin of MoVNbTeOx, (post-) treatment of the catalyst, material characterization, reaction mechanism, and evaluation as well as the reactor design, providing a comprehensive overview of M1 MoVNbTeOx catalysts for the oxidative dehydrogenation of ethane, thus contributing to the understanding and development of the ODHE process based on MoVNbTeOx catalysts.

• Sorbents exhibit better cyclic performance of ∼ 0.6 g/g in CO 2 in-situ capture and conversion condition. • Sorbent prepared by sol–gel method has the excellent performance with 0.41 g/g and 0.58 g/g. • The spinel catalyst was first reported in the in-situ CO 2 capture and conversion. • The CO 2 uptake capacity and ethylene yield can increase with the decrease of content of sorbent in DFM. • The critical mechanism of in-situ CO 2 capture and conversion was summarized. The coupling technology (CaLODHE) of calcium looping (CaL) and oxidative dehydrogenation of ethane (ODHE) has recently attracted numerous attentions. However, the optimization of the CaO-based sorbent in CaLODHE has not been extensively reported to date. In this work, a comparative study of the CO 2 capture performances of the CaO-based sorbents by different synthesis methods (i.e., dry-mixing, wet-mixing, sol–gel, and coprecipitation) tested in CaL and CaLODHE conditions was conducted. The results show that the sorbent by the sol–gel method in CaLODHE condition has the highest cyclic capture performances of around 0.6 g/g during 20 cycles, attributed to the porous structure and homogeneously dispersed CeO 2. In addition, the dual functional material (DFM) with CaO-based sorbent and MgGaAlO 4 catalyst was first synthesized and the performances of DFM with different mixing ratios of sorbent and catalyst were investigated. The results show that the DFM with the sorbent and catalyst of the same quality has a balanced performance, and the CO 2 uptake capacity and conversion are 0.27 g/g and 57%, and the ethane conversion and ethylene selectivity are 56.9% and 74.2%, respectively. In addition, the reaction mechanism of CaLODHE was also proposed in depth. [ABSTRACT FROM AUTHOR]

• Impact of the axial effective thermal conductivity (k eff,z) on hot spots prediction. • Adequate characterization of k eff,z from adiabatic experimental conditions. • Considering k eff,z is crucial to avoid runaway mispredictions. • Evaluation of the Oxidative Dehydrogenation of Ethane industrial reactor model. The impact of axial conductive heat transfer on the simulation and prediction of hot spots and, more particularly, runaway, within an industrial-scale wall-cooled packed-bed reactor with low tube-to-particle diameter ratio (d t /d p ∼ 3) has been assessed in this work. To this purpose, the effective axial conductivity (k eff,z) was first determined from adiabatic experiments in a bench-scale packed bed in the absence of reaction. Next, non-adiabatic and non-isothermal bench-scale and industrial-scale packed bed experimental data were used in the assessment of the impact of axial heat conduction on the prediction of the temperature profile. The so-called Pseudo-local Internal Heat Transfer Approach (PL-IHTA) was used for the adequate description of the radial temperature gradients. Finally, an industrial-scale wall-cooled packed bed reactor for the highly exothermic catalytic oxidative dehydrogenation of ethane was modeled to assess the impact of the axial thermal conductivity on temperature profile simulations. When disregarding axial heat conduction or adopting literature-based values for k eff,z , determined from either experiments at low d t /d p ratios (<8) and Re p ≤ 1000 or high d t /d p ratios (>8) and Re p ≤ 700 at a wide panel of operating configurations, runaway is simulated at conditions where it has not been observed experimentally or a negligible hot-spot prediction is obtained. When considering the k eff,z determined for the specific reactor configuration in this work, hot spots are predicted at Re p of 700 and 1400, but no runaway. The discrepancies between experimental findings and temperature profiles simulated using literature-based values for k eff,z indicate the need for a specific determination of k eff,z in packed bed reactors with low d t /d p ratio to more accurately predict hot spots, resulting in more reliable reactor design and operation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanisms of C 2 H 6 oxidation and C 2 H 4 production on sIrO2(1 1 0) were revealed. • Diffusion kinetics is critical to properly understand the simulated TPRS spectra. • The results provide further insights into controlling the reactivity of metal oxides to increase the selectivity. The catalytic oxidative dehydrogenation of alkane can be an attractive way to produce olefines from light alkanes which are major components of natural gas. This study examined C 2 H 6 oxidation on a stochiometric IrO 2 (1 1 0) surface, which has a high potential to produce C 2 H 4 production at a low temperature of ∼ 400 K using density functional theory calculation and microkinetic simulation. The DFT simulation predicted two main complete oxidation mechanisms of dehydrogenation-based oxidation and C 2 H x O formation-based oxidation. With DFT-derived energetic data, microkinetic simulation for C 2 H 6 oxidation was performed on stochiometric IrO 2 (1 1 0) TPRS spectra. The simulation confirmed that C 2 H 6 oxidation during TPRS mainly follows the dehydrogenation-based complete oxidations (C 2 H 6 → C 2 H 5 → C 2 H 4 → C 2 H 3 → C 2 H 2 → C 2 H → C 2 → C 2 O → CO + C). In addition, the production of C 2 H 4 (g) stems from the cooperative steps of C H bond recombination from C 2 H 3 and subsequent desorption. The computational findings cannot be produced without the proposed concept of a surface diffusion-limited reaction, which can resolve the errors of overestimated rates by the mean field approach. This finding suggests that the diffusion kinetics can be critical for understanding the TPRS features when simulating TPRS spectra by mean field-based microkinetic simulation. Our results provide a solid understanding of C 2 H 6 oxidation and C 2 H 4 production mechanisms on sIrO 2 (1 1 0). [ABSTRACT FROM AUTHOR]

• Alkali and alkaline earth perovskites have similar active sites for OCM and ODHE. • Moderate and strong basic sites assist OCM and moderate basic sites expedite ODHE. • V f affects CH 4 , C 2 H 6 , and O 2 conversions, while χ A + χ B affects basicity. • Crystal phase transition and metal-oxygen energy alter moderate basic sites. • Moderate V f , low electronegativity, and variable crystal phase augment reactivity. In this study, alkali metal and alkaline earth metal perovskites have been synthesized using simple preparation methods for catalyzing the oxidative coupling of methane (OCM) and oxidative dehydrogenation of ethane (ODHE). The influence of their structural parameters (such as tolerance factor t, unit cell free volume (V f), electronegativity of A- and B-site elements, average metal-oxygen energy, and crystalline phase transition) on basic sites and reaction performance is also systematically investigated. The results show that these two perovskites have similar active sites for OCM and ODHE reactions, with the moderate and strong basic sites favoring the OCM reaction and the moderate basic site facilitating the ODHE reaction. The surface basicity of these perovskites reflects the electron-donating ability of lattice oxygen, which in turn affects the production of reactive oxygen species (O 2 −, O 2 2−, and O−). Moderate basic sites are abundant and closely related to oxygen vacancies, with high oxygen vacancy concentrations generating abundant reactive oxygen species. Meanwhile, V f values of perovskites govern the CH 4 , C 2 H 6 , and O 2 conversions, the electronegativity of elements affects the catalyst basicity, and the average metal-oxygen energy and crystalline phase transition alter the moderate basic sites. Overall, it concludes that perovskites should meet the following conditions to achieve excellent catalytic performance for OCM and ODHE: moderate V f , low electronegativity of A- and B-site elements, low average metal oxygen energy, and a crystalline structure that changes with temperature. [Display omitted] [ABSTRACT FROM AUTHOR]

MoVO, MoVTeO and MoVTeNbO mixed oxides, prepared hydrothermally and heat-treated in N 2 at 400, 500 or 600 °C, are active and selective catalysts in the oxidative dehydrogenation (ODH) of ethane, although their catalytic behaviour strongly depends on the composition and the activation temperature of the material. Thus, the selectivity to ethylene over samples heat-treated at 400 or 600 °C, decreases according to the following trend: MoVTeNb-600 > MoV-400 > MoVTe-600 > MoVTe-400 > MoVTeNb-400 >> MoV-600 (with catalysts heat-treated at 500 °C presenting an intermediate performance). This catalytic performance can be explained to a high extent by the presence of the M1 phase in the best catalysts. Interestingly, the temperature of formation and decomposition of the M1 phase strongly depends on the chemical composition of the catalysts, leading to different trends depending on the heat-treatment temperature. Not only the presence of the M1 phase determines the catalytic performance but also the V4+/V5+ ratio in the surface of catalysts. Additionally, a comprehensive brand-new electrochemical characterization of the catalysts has been carried out for MoV-based samples with M1 phase. Accordingly, the best catalytic behaviour in terms of selectivity to ethylene in the ethane ODH was observed in those materials presenting higher charge-transfer resistances at the interfacial active parts and n -type semiconductivity with few O-vacancies. Besides, lower current densities obtained in cyclic voltammetries (related to low electrochemical activity) has been associated with higher selectivity in the ODH reaction. [Display omitted] • Comparison of different MoVO, MoVTeO and MoVTeNbO M1 phase catalysts in ethane ODH. • The M1 crystalline phase is key to obtain good selectivity to ethylene in ethane ODH. • Catalytic performance optimized by the higher presence of surface V4+ species. • Correlations between electrochemical and catalytic properties in M1-based materials. [ABSTRACT FROM AUTHOR]

The template-induced mesoporous Ni–Al oxide catalysts synthesized by a template-assisted self-assembly route show the good mobility of selective oxygen species and tuned physico-chemical properties, thus promoting their catalytic performance and stability for the oxidative dehydrogenation of ethane using O 2 as an oxidant. [Display omitted] • Template-induced mesoporous Ni–Al mixed oxides are successfully prepared. • Structural effect and strong interaction are crucial to enhance ODHE performance. • Template-induced mesoporous Ni–Al mixed oxides exhibit preferable ODHE performance. • Adding template significantly enhances coking resistance. • Ni–Al–F127 catalyst shows a C 2 H 4 yield of 37.3 % and prominent stability for 150 h. Oxidative dehydrogenation of ethane is a potential industrial process to produce ethylene. In this work, the template-induced mesoporous Ni–Al mixed oxide catalysts synthesized by the template-assisted self-assembly method were investigated for the oxidative dehydrogenation of ethane to ethylene using O 2 as an oxidant. The template-induced structure evolution is an effective means to modulate physico-chemical properties of the Ni–Al mixed oxide, thus, it further improves the catalytic performance. All the mesoporous Ni–Al–template catalysts present higher C 2 H 6 conversions and C 2 H 4 selectivities than bulk NiO and non-porous Ni–Al–O catalysts in the temperature range of 350–500 °C. Meanwhile, up to 49.6% C 2 H 6 conversion and 75.3% C 2 H 4 selectivity (37.3% of C 2 H 4 yield) can be obtained over Ni–Al–F127 catalyst at 500 °C. And the mesoporous Ni–Al–F127 catalyst exhibits a superior stability after a long run. The structure–performance correlation indicates that the remarkable catalytic performance is ascribed to the synthesis driven structural effect. The strong interaction between Ni and Al cations caused by the addition of template promotes the formation of small NiO particles and the better dispersion of NiO, which decreases the content of non-selective oxygen species and increases the availability of lattice oxygen. [ABSTRACT FROM AUTHOR]