Ceria-supported Ni/MCM-22 catalysts with weight ratio of Ni:CeO2 (9:0, 9:4, 9:8, 9:12) were prepared by a sol–gel method. The effect of CeO2 on activity and stability of catalysts was evaluated at 700–750 °C with gas hour space velocity of 2.4× 104 mL g–1 h–1. The presence of CeO2 in Ni/MCM-22 suppressed effectively the accumulation of coke on active Ni0 sites via the oxygen storage capacity on the interface between elemental nickel and CeO-Si groups of MCM-22. H2 temperature-programmed reduction results illustrated that CeO2 reduced the interaction between Ni and MCM-22 and increased the high dispersion of Ni nanoparticles, which is easily reducible. The 8CeO2 9Ni/MCM-22 catalyst performed the best at 750 °C with the lowest carbon deposition during time on stream of 60 h, plausibly due to the presence CeO2, which promotes C–H activation. Moreover, the surface oxygen species on the catalyst can interact with the coke generated during reaction to suppress the formation of coke.

•CaO supported Ni/MCF catalysts were prepared by a sol-gel & wetness impregnation method.•The production of hydrogen is influenced by using CaO as promoter in MDR reaction.•The presence CaO accelerates the removal of carbon and responsible for high durability of catalysts.•Catalyst 9CaO 9Ni/MCF prepared by sol-gel method remained the best.•Sol–gel method showed better catalytic activity than wetness impregnation method.CaO doped Ni/MCF catalysts were prepared by conventional incipient wetness impregnation and sol-gel methods for the study of methane dry reforming reaction. The fresh and used catalysts were characterized using H2 temperature programmed reduction (H2-TPR), X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC) and O2 temperature-programmed oxidation (O2-TPO). XRD exhibited that CaO and Ni particles are dispersed on the surface of catalyst. The Ni:CaO ratio was adjusted for the improvement of pore textural properties on behalf of enhancement of metal particle dispersion for increased catalytic performance and anti-coking. The catalytic performance and stability of the catalysts for methane dry reforming reaction were studied at 700–750 °C at atmospheric pressure with GHSV of 24000 mL g−1h−1 having same feed ratio of CH4:CO2 = 1. Experimental results exhibited that catalyst prepared by a sol-gel method showed superior catalytic activity, stability and resisted carbon deposition than catalyst prepared incipient wetness impregnation method. Among all tested catalysts 9CaO 9Ni/MCF catalyst remained the best for catalytic performance and anti-coking activity due to higher metal dispersion with small metal particles, as well as the synergetic effect between CaO and Ni. During 75 h stability test over the catalyst 9CaO 9Ni/MCF the CH4 and CO2 conversion remained 91% and 99% respectively.

•Hydrogen and syngas production is interesting from corncob/CO2 reforming reaction.•Segregation action of CeO2 promoted high dispersion of nickel particles.•4CeO2 9Ni/MCM-22 presented the best catalytic activity and stability.A series of xCeO2.9Ni/MCM-22 catalysts (Ni: CeO2 weight ratio 9:0, 9:1, 9:2, 9:4, 9:8, 9:12) was prepared by a sol-gel method. The production of hydrogen from corncob (biomass) was performed using CO2 dry reforming reaction. The performance of the catalysts was evaluated in the presence of CO2 and/or air at atmospheric pressure for H2 and CO product distribution from corncob at different temperatures. The presence of CeO2 in Ni/MCM-22 results in the enhancement of initial catalytic activity, while 4%CeO2 9Ni/MCM-22 catalyst performed the best, exhibiting excellent catalytic activity at different reaction conditions. The fresh and used catalysts in corncob/CO2 reforming reaction were characterized by N2-physisorption, XRD, FT-IR, H2-TPR, O2-TPD, CO2-TPD, UV–Vis, TG/DSC and Raman spectroscopy.

•xMg/La yCo zNi/MSU-S catalysts were prepared by a sol gel method.•La eliminates the deposited carbon and reduce the excessive aggregation of Ni particles.•3La 2Co 7Ni/MSU-S catalyst exhibited superior stability during CO2/CH4 reforming at 750 °C.•Carbon deposition was the main reason for the deactivation of catalyst.A series of xMg/La yCozNi/MSU-S catalysts were prepared by a sol–gel method and characterized by means of N2-physisorption, FT-IR, H2-TPR, CO2-TPD, H2-TPD, XRD, HRTEM, TG/DSC and O2-TPO techniques. The catalytic performance of the catalysts was evaluated for H2 and syn gas production at different temperatures at atmospheric pressure. The effect of reaction temperature, catalyst composition and performance of the catalyst were investigated during CO2 dry reforming reaction at 700–800 °C with GHSV of 2.4 × 104 mL/g−1 h−1. The results indicated that upon La, Mg and Co promotion, the Ni nanoparticles are highly dispersed on the mesoporous walls of MSU-S via strong interaction between metal ions and the HO–Si-groups of MSU-S. The presence of La2O3 in xLayCozNi/MSU-S results in enhancement of initial catalytic activity as compared to xMgyCozNi/MSU-S. It revealed that 3 La 2Co 7Ni/MSU-S performed the best with highest CH4 and CO2 conversion showing outstanding catalytic activity, greater stability and low coking for 50 h during 75 h time on stream at 750 °C.

Mesoporous aluminosilicate with ZSM-5 structure was synthesized from ZSM-5 nanoclusters and used as support, which possessed strong acidity, large surface areas, and high hydrothermal stability. A series of 0–12 wt % MgO–10 wt % Ni/MAS-24 were prepared via a sol–gel method and characterized by XRD, N2 adsorption, FT-IR, H2-TPR, CO2-TPD, UV–vis, TG/DSC, and HRTEM techniques. The effects of catalyst composition and reaction temperature on the catalytic performance in CO2/CH4 reforming were studied. The catalytic stability over 9 wt % MgO-10Ni/MAS-24 for 60 h indicated that the conversion of CH4 and CO2 maintained 93% and 99%, respectively, the selectivity of H2 and CO for 99% at 800 °C, although the conversion of CH4 decreased to 83% in the later 30 h due to high dispersion of Ni particles via synergistic action between MgO and NiO nanoparticles as well as basic effect on the surface, which prevented Ni0 active particles from aggregating and coke formation during the CH4/CO2 reforming reaction.

A simple and facile solvothermal method is developed for the preparation of a reduced graphene oxide/NH2-MIL-125(Ti) (rGO–NMTi) hybrid nanocomposite photocatalyst with large specific surface area and thermal stability. This rGO–NMTi-x hybrid nanocomposite exhibited a more efficient photocatalytic performance than NH2-MIL-125(Ti) for methyl blue (MB) degradation under visible-light irradiation due to the synergetic action between rGO and NH2-MIL-125(Ti). Therefore, rGO/MOFs photocatalysts have great potentiality in environmental remediation. The structure and physical properties of rGO, NH2-MIL-125(Ti) and rGO–NMTi-x hybrid nanocomposites were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), N2 adsorption/desorption, high resolution transmission electron microscopy (HRTEM), laser Raman, UV-visible absorption spectra (UV-DRS) and FT-IR techniques.

•Pore structure and thermal stability of support played important roles during desulfurization.•Doping rare earth oxides promoted high dispersion of active particles.•Induced effect of rare earth oxides are CeO2 > La2O3 > Sm2O3.•Steam in hot coal gas suppressed the desulfurization efficiency and precision.•Mn/MCF sorbent was stable with complete regenerated ability.A Mn-based sorbent with high desulfurization efficiency were fabricated using various mesoporous silica as support and doping rare earth oxides, and their physical properties were characterized by means of XRD, BET, H2-TPR, CO2-TPD, O2-TPD and UV–Vis techniques. The results indicated that Mn/MCF exhibited the highest desulfurization performance among Mn/MCM-41, Mn/SBA-15, Mn/MCM-48 and Mn/MCF due to the 3-D ultra-large mesopores and excellent thermal stability of MCF at 700 °C. Doping rare earth oxides into Mn/MCF can make the high dispersion of active particles. But the breakthrough sulfur capacities (BSCs) over 95Mn5Ce/MCF, 95Mn5La/MCF and 95Mn5Sm/MCF sorbents are lower than Mn/MCF sorbent due to the lower BSCs of CeO2, Sm2O3 and La2O3 themselves and the lower SBET and VT. The desulfurization efficiency and precision further declined with increasing steam content for Mn/MCF sorbent. The high sulfur capacity over the Mn/MCF sorbent was maintained during the five consecutive desulfurization/regeneration cycles.

To enhance the stability of sorbents during continuous desulphurization–regeneration cycles, KIT-6 with 3D pore channels was used as a support for the sorbents. A series of mesoporous xLayMn/KIT-6 sorbents with different La/Mn atomic ratios were fabricated using a sol–gel method and their desulphurization properties of hot coal gas were investigated at 700–850 °C. 3La97Mn/KIT-6 performed the best at 800 °C with a breakthrough sulphur capacity of 11.56 g sulphur per 100 g sorbent. The eight successive desulphurization (800 °C)–regeneration (600 °C) cycles revealed that 3La97Mn/KIT-6 with endurable regeneration abilities could retain 80% of the initial sulphur capacity. It indicated a better desulphurization performance compared to pure 3La97Mn and 3La97Mn/MCM-41. The fresh and used xLayMn/KIT-6 sorbents were characterized by means of BET, XRD, HRTEM, XPS and H2-TPR techniques. The XRD patterns and HRTEM images of fresh and used 3La97Mn/KIT-6 verified that the utilization of KIT-6 effectively suppressed the aggregation of Mn2O3 particles and improved the stability of the sorbent.

Hexagonally ordered mesoporous MSU-S was assembled from nanoclustered zeolite seeds. The XRD and BET results verified that after treated in 10%H2O/N2 atmosphere at 800 °C for 2 h, MSU-S still remained a well-ordered hexagonal structure due to rich acidic sites and excellent hydrothermal stability. A series of SmxMnyOz/MSU-S sorbents were prepared by a sol–gel method. The desulfurization performances of the 55%Sm5Mn95/MSU-S sorbent were improved significantly due to high hydrothermal stability of MSU-S with high surface area as well as the synergistic effect between Mn and Sm2O3. The result of eight successive sulfurization/regeneration cycles of sorbent illustrated that high breakthrough sulfur capacity and endurable stability of 55%Sm5Mn95/MSU-S correlated closely with the existence of the framework 4-coordination aluminum (NH3-TPD, 27Al MAS NMR) and high dispersion of Sm/Mn species on MSU-S (XRD, TPR) for H2S removal. HRTEM images and SAED patterns confirmed that fresh 55%Sm5Mn95/MSU-S existed in high ordered mesoporous structure and the nanosized Sm2O3 and Mn3O4 particles occurred in highly dispersive polycrystallites. The valence state of Mn species and the regeneration process of used sorbent were characterized by X-ray photoelectron spectroscopy (XPS) and TG/DSC. In addition, the effects of reaction temperature, feed composition and Sm/Mn atomic ratio in sorbents on desulfurization performance were investigated.

In order to improve the desulfurization efficiency of 50% MnxOy/MCM-48 sorbent, the preparation parameters including synthesis method (excessive impregnation, precipitation, and sol–gel), precursor selection (Mn(Ac)2 and Mn(NO3)2), heating rate during calcination (2°/min, 4°/min, 6°/min, and 8°/min), and calcination temperature (450 °C, 550 °C, 650 °C, and 750 °C) of sorbents were investigated systematically. The structure and composition of different sorbents were characterized by XRD, BET, TG/DSC, H2-TPR, UV–vis, TPSR, and FT-IR techniques. The results indicated that synthesis methods and precursors influenced remarkably the dispersion of active particles while the stable structure of MCM-48 and the dispersion of active particles correlated closely with the heating rate during calcination and calcination temperature of sorbents, which will influence the desulfurization efficiency of sorbents. Therefore, the better dispersion of active particles and integrity of MCM-48 structure will result in better desulfurization performance of sorbents. Thus, the best condition was the calcination temperature of 550 °C with a heating rate of 2°/min using Mn(Ac)2 as precursor by a sol–gel method.

The improved deactivation kinetic model over mesoporous LaFeO3/MCM-41 sorbents for hot coal gas desulfurization was established with mass-transfer correlation based on elementary stoichiometric equation, which consisted of both the spatial and the time partial differential equations. MATLAB software was used to solve partial differential equations by means of forward finite differential method and to estimate kinetic parameters via nonlinear least-squares fitting. The rate constants ka and kd were obtained via aforementioned kinetic model over different LaFeO3/MCM-41 sorbents. The calculated results were in accordance with experimental data under various operating conditions. The kinetic model can be used successfully to predict the distributions of H2S concentration at different times and spatial positions within fixed-bed layers, compared to unreacted shrinking core model, random pore model, or grain model. It is of very great significance to obtain basical chemical engineering data for the design of new reactor. For 50%LF2/MCM-41 sorbent, the calculated apparent activation energy (Ea) and deactivation energy (Ed) for chemical reaction of LaFeO3 active sites are 32.1 and 15.1 kJ·mol–1, respectively, based on the experimental data of desulfurization process.

Mesoporous aluminosilicate (designated as MAS-9) was synthesized through assembling ZSM-5 nanocrystallites as precursors with P123 as surfactant, which exhibited excellent properties, such as large specific surface area, big pore volume, uniform pore distribution, and high hydrothermal stability. A series of LaxNiyOz/MAS-9 catalysts for CH4/CO2 reforming were prepared by the sol–gel method. Support and catalysts were characterized using N2-adsorption, X-ray diffraction, Fourier transform IR, inductively coupled plasma–mass spectrometry, H2 temperature-programmed reduction, thermogravimetric/differential scanning calorimetry, and high-resolution transmission electron microscopy techniques. The adjustment of the La/Ni molar ratio will be beneficial to the enhancement of Ni0 particle dispersion and decrease of particle size, which increased the catalytic activity and the resistance to carbon deposition. Under the condition of an atmospheric pressure at 850 °C and a gas hour space velocity of 3.2 × 104 mL·g–1·h–1, the conversion of CH4 and CO2 over LaNi2Ox/MAS-9 catalyst was 100%, and the selectivities of H2 and CO were 95% and 99%, respectively. In addition, the stability test of LaNi2Ox/MAS-9 catalyst for 145 h revealed that the conversion of CO2 (100%), the selectivity of H2 (95%) and CO (99%), with a H2/CO ratio of 0.96 as well as carbon yield (ca. 1%) almost kept constant although conversion of CH4 slightly decreased to 94%. The mesoporous structure of MAS-9 kept intact after 145 h CH4/CO2 reforming. Therefore, LaNi2Ox/MAS-9 was a promising catalyst for CH4/CO2 reforming.

•The addition of Y2O3 improved significantly the dispersion of Ni0 particles.•The synergistic mechanism of Y2O3 for carbon formation and removal was proposed.•9%Y–NiO/SBA-15 catalyst exhibited superior stability during CO2/CH4 reforming.A series of Y2O3-promoted NiO/SBA-15 (9 wt% Ni) catalysts (Ni:Y weight ratio = 9:0, 3:1, 3:2, 1:1) were prepared using a sol–gel method. The fresh as well as the catalysts used in CO2 reforming of methane were characterized using N2-physisorption, XRD, FT-IR, XPS, UV, HRTEM, H2-TPR, O2-TPD and TG techniques. The results indicate that upon Y2O3 promotion, the Ni nanoparticles are highly dispersed on the mesoporous walls of SBA-15 via strong interaction between metal ions and the HO–Si-groups of SBA-15. The catalytic performance of the catalysts were evaluated at 700 °C during CH4/CO2 reforming at a gas hourly space velocity of 24 L gcat−1 h−1(at 25 °C and 1 atm) and CH4/CO2molar ratio of 1. The presence of Y2O3 in NiO/SBA-15 results in enhancement of initial catalytic activity. It was observed that the 9 wt% Y–NiO/SBA-15 catalyst performs the best, exhibiting excellent catalytic activity, superior stability and low carbon deposition in a time on stream of 50 h.

A series of xMnyCe/hexagonal mesoporous silica (HMS) sorbents with wormhole-like structure was prepared by a sol–gel method, and their performance for hot coal gas desulfurization was investigated at 600 °C. All xMnyCe/HMS sorbents exhibited high breakthrough sulfur capacity, and the utilization of these sorbents was much higher than that of 10Mn/HMS. The breakthrough sulfur capacity over 4Mn1Ce/HMS sorbents was 121.7 mg of S/g of sorbent with the utilization of 82.4%. Such a behavior was maintained in eight consecutive desulfurization–regeneration cycles. The effects of the desulfurization temperature, H2 concentration, and 7% steam on the performance of 4Mn1Ce/HMS were examined. The fresh, used, and regenerated samples were characterized by means of X-ray diffraction, N2 adsorption, Fourier transform infrared absorption spectroscopy, and high-resolution transmission electron microscopy techniques. The results confirmed that the manganese oxide was dispersed highly on the HMS support because of the synergetic effects of manganese oxide and ceria oxide, and the wormhole-like structure in sorbents promoted the diffusion of H2S molecules. The Brunauer–Emmett–Teller results revealed that the wormhole-like mesoporous structure in sorbents remained intact even after the eighth successive desulfurization/regeneration cycle.

Mesoporous La/MCM-41 and La/AlMCM-41(SiO2/Al2O3 = 30, 50) sorbents were prepared by an incipient wetness impregnation or ion-exchange (IE) process, and desulfurization performances were investigated for commercial diesel containing total sulfur of 560 ppmw at ambient temperature and pressure. The high surface area, a big pore volume and diameter of sorbents played important role for sulfur removal efficiency. The sorbents were characterized by means of BET, XRD, HRTEM, ICP-MS, NH3-TPD and Py FT-IR techniques. The results of N2-adsoption isotherms, XRD, HRTEM and FT-IR for the sorbents revealed that no structure collapse occurred during the wet impregnation. The interaction between sulfur in thiophene and HO-La(OSiAl) was crucial for the removal of sulfur compounds.Highlights► High surface area of sorbents played important role in sulfur removal. ► Interaction between S–La species was crucial for removal of sulfur. ► BET, XRD, HRTEM and FT-IR characterization indicates that structure of MCM-41 remains intact.

Nanoporous carbon (NPC)/Ni–P composite membranes were prepared on electroless Ni-plating-modified porous stainless steel tubes (PSSTs) by carbonizing polyimide or cellulose acetate precursors at 700 °C in a nitrogen atmosphere. The performance of the membranes was evaluated by single-gas permeation and binary-gas mixture separation. The effects of the substrate with or without modification on gas permeation were studied, and the diffusion mechanism of the gases through the membranes was analyzed. The real separation factors of gas mixtures through the NPC/Ni–P composite membranes were much higher than those through the nanoporous carbon membranes (NPCMs) prepared on the unmodified substrate, especially those for H2/CH4 and H2/CO2. The weight loss rate of polymer precursors was investigated by TG/DTG. The specific surface areas of the membranes and the crystallization of the Ni–P alloy layer were characterized by means of the BET and DSC techniques, respectively, indicating that localized electroless Ni plating can reduce the pore diameter of PSST effectively and regulate the pore size distribution.

We prepared LaMeOx/MCM-41 (Me = Co, Zn, Fe) sorbents of high specific surface area by means of sol–gel method. For comparison purposes, the unsupported composite metal oxides were also synthesized. Breakthrough and total sulfur capacity over LaFeO3/M41 were 3.24 and 3.70 g, respectively, significantly higher than the former (0.35 g) over unsupported LaFeO3. The materials were characterized using Brunauer, Emmett and Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (H2-TPR), temperature-programmed reduction and sulfidation (TPRS), and high-resolution transmission electron spectroscopy (HRTEM) techniques. Their ability for H2S removal was evaluated over a fixed-bed reactor, and the effects of reaction temperature, feed composition, and support on desulfurization were studied. The results of successive sulfidation/regeneration cycles (×10) revealed that the LaFeO3/M41 sorbent was stable enough for desulfurization of hot coal gas in chemical industry.Graphical abstractHighlights► LaMeOx/M41 (Me = Fe, Zn, Co) sorbents of high specific surface area was prepared by means of sol–gel method. ► Channel structure of MCM-41 promotes the diffusion of H2S molecules and enhances sulfidation rate of LaFeO3/M41. ► Structure of LaMeOx/M41 remains intact after sulfidation. ► MCM-41 as a support promotes attrition resistance and enhances the mechanical strength of sorbents.

The catalytic performance of Zn-based/HZSM-5 catalysts prepared by wet impregnation method was investigated for the methane dehydroaromatization (MDA) reaction under the conditions of atmospheric pressure and supersonic jet expansion (SJE). The physical properties of the catalysts were characterized by Brunauer–Emmett–Teller (BET), Fourier transform infrared (FT-IR), temperature-programmed reduction of H2 (H2-TPR), temperature-programmed desorption of NH3 (NH3-TPD), X-ray photoelectron spectroscopy (XPS), thermogravimetric and differential thermogravimetric (TG/DTG), and high-resolution transmission electron microscopy (HRTEM) techniques. The results revealed that under SJE condition the Zn/HZSM-5 catalyst exhibited high catalytic activity. It was found that because of the rapid migration of H+ ions on the catalyst, the activation of CH4 at active sites of nano-ZnO is facile. A new reaction mechanism that involves an active “ZnO–CH3+...–HZnO” intermediate formed as a result of synergetic action between ZnO and HZSM-5 has been proposed for CH4 dissociation and dehydrogenation. Under atmospheric pressure, however, the catalytic activity of Zn/HZSM-5 is low.

Ohmic contact electrodes with high performance were formed on the surface of BaTiO3-based thermisitors by localized electroless Cu-plating and the physical properties of the coated thermistors were investigated. The adhesive force between the electroless plated layer and the substrate, the voltage-resistance, the resistance, the ageing-resistance properties, and the solderability, all met the industrial production requirements for thermistors. The structure and morphologies of these NiP–Cu composite electrodes as well as the ceramic substrates were characterized by X-ray diffraction and atomic force microscopy, verifying that the film contains a typical Cu crystal structure with preferred orientation of the copper grains.

Corncob, a widespread and inexpensive natural resource in China, was used to prepare activated carbon (AC) by chemical activation with potassium hydroxide (KOH). The adsorption equilibrium and kinetics of H2, CH4, and CO2 on AC were investigated at different temperatures. Adsorption isotherms of H2, CH4, and CO2 were correlated with the Langmuir and Freundich equations, and the heat of adsorption was determined. It was revealed that the Freundich adsorption equation was more apt to describe the adsorption procedure of H2, CH4, and CO2 compared to the Langmuir equation. Two simplified kinetic models including pseudo-first-order and -second-order equations were used to evaluate the adsorption processes. The results indicated that the adsorption of H2, CH4, and CO2 could be described properly by a pseudo-second-order equation. The kinetic parameters of this model were calculated and discussed.

An industrial cylinder Ni-based catalyst, LaNiOx/ZSM-5 (ϕ = 3 mm), was prepared by a sol−gel method, and its catalytic performance was investigated for CH4/CO2 reforming reaction not only in laboratory scale but also in pilot plant scale. The result revealed that the conversion of CH4 and CO2 was 97% and 94%, respectively, at 850 °C and gas hour space velocity = 1.3 × 103 h−1 and remained a constant in the 100 h range, whereas carbon yield was ca. 5%. The properties of the catalyst were characterized by means of techniques such as X-ray diffraction (XRD), Brunauer−Emmett−Teller (BET) surface area, high-resolution transmission electron microscopy (HRTEM), temperature-programmed reduction (TPR), and temperature-programmed oxidation (TPO) and compared to those of La2NiO4/MCM-41 and La2NiO4/γ-Al2O3 catalysts.

CO2 reforming of methane into syngas over Sm2O3−La2O3 (SL)-supported Ni catalyst was investigated in a fixed-bed quartz reactor and the best catalytic activity was observed over Ni/SL (sol−gel) due to the reduction of the perovskite LaNiO3 and spinel La2NiO4 to form small nickel particles. The conversion of CH4 and CO2 over Ni/SL(sol−gel) were 55% and 57%, respectively, the selectivity of H2 and CO were 96% and 98%, significantly higher than those over Ni/SL (imp) catalyst at 700 °C and a GHSV of 4.8 × 104 mL·h−1·g−1cat. In the meantime, the Sm2O3−La2O3-supported Ni catalysts were characterized by means of techniques, such as BET, XRD, H2-TPR, TG/DTA, HRTEM, XPS, and XAES.

A series of La2O3−V2O5/MCM-41 catalysts with high specific surface area were prepared by means of incipient wetness impregnation for the dehydrogenation of ethylbenzene to styrene using CO2 as oxidant. At 600 °C, the conversion of ethylbenzene and selectivity to styrene over 10La15V/MCM-41 after an on-stream time of 4 h was about 86.5 and 91.0%, respectively. The properties of the catalysts before and after the reaction were characterized using techniques such as X-ray diffraction, specific surface area, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, and oxidation. The high catalytic activity and stability of 10La15V/MCM-41 during dehydrogenation of ethylbenzene is attributed to an optimized La/V atomic ratio. The accumulation of amorphous carbon species on the external surface of La2O3−V2O5/MCM-41 is the cause for catalyst deactivation.

Methane dehydroaromatization over the Mo/HZSM-5 catalyst under supersonic jet expansion condition was investigated via direct monitoring of the reactant and products using time-of-flight mass spectrometry. Our results showed that methane conversion was efficient, and differing from the result observed over the same catalyst at atmospheric pressure, naphthalene was the major product. The jet expansion approach for direct methane dehydroaromatization is expected to be more favorable for the production of hydrogen, which is important for fuel cell application. In addition, the effects of reaction temperature, time on stream, and pulsed laser (Nd:YAG at 266 nm) energy on the distribution of products were investigated.TOF-MS signals of methane dehydroaromatization products with laser power at about 13.5 mJ. The insertion shows the enlarged details in the vicinity between C2+–C6+ ions.

Analcime (ANA) zeolite fibers with an average diameter of 300–600 nm were prepared for the first time by means of the in situ TPAOH template electrostatic self-assembly technique. In this paper, the conditions of its formation such as pH of synthesis sol and effect of α-Al2O3 plates have been described in detail. The structure and thermal stability of the fibers have been confirmed by means of XRD, FT-IR, and DTA analyses. The surface morphology, size distribution, and elemental composition of ANA nanoparticles have been characterized by HRTEM and SEM-EDX approaches.

Activated carbon (AC) was fabricated from corncob, which is cheap and abundant. Experimental parameters such as particle size of corncob, KOH/char weight ratio, and activation temperature and time were optimized to generate AC, which shows high methane sorption capacity. AC has high specific surface area (3227 m2/g), with pore volume and pore size distribution equal to 1.829 cm3/g and ca. 1.7–2.2 nm, respectively. Under the condition of 2 °C and less than 7.8 MPa, methane sorption in the presence of water (Rw = 1.4) was as high as 43.7 wt% methane per unit mass of dry AC. The result is significantly higher than those of coconut-derived AC (32 wt%) and ordered mesoporous carbon (41.2 wt%, Rw = 4.07) under the same condition. The physical properties and amorphous chaotic structure of AC were characterized by N2 adsorption isotherms, XRD, SEM and HRTEM. Hence, the corncob-derived AC can be considered as a competitive methane-storage material for vehicles, which are run by natural gas.An activated carbon with specific surface area of 3227 m2/g and pore volume of 1.829 cm3/g was fabricated from corncob. CH4 of 43.7 wt% was stored in the hydrate form at 275 K and 7.8 MPa.Download full-size image

CH4/CO2 reforming over La2NiO4 and 10%NiO/CeO2–La2O3 catalysts under the condition of supersonic jet expansion was studied via direct monitoring of the reactants and products using the sensitive technique of cavity ring-down spectroscopy. Vibration–rotational absorption lines of CH4, H2O, CO2 and CO molecules were recorded in the near infrared spectral region. Our results indicated that La2NiO4 is superior to 10%NiO/CeO2–La2O3 in performance. In addition, we observed enhanced reverse-water-gas-shift reaction at augmented reaction temperature. The formation of reaction intermediates was also investigated by means of time-of-flight mass spectrometry and there was the detection of CHx+, OH+ and H+ species.

•CaO-MnOx/MSU-H exhibited high capacity and endurable regeneration ability.•Utilization of MSU-H improved dispersion of particles and diffusion rate of gas.•Ca species played dual roles for high dispersion of Mn2O3 and effective sorption of H2S/H2O.•90Mn10Ca/MSU-H sorbent presented outstanding H2O-resistance ability.A series of xMnyCa/MSU-H sorbents with various Mn/Ca molar ratio were first designed and synthesized with a sol-gel method. The desulfurization performance of the new sorbent was investigated at 600–800 °C in hot coal gas. 90Mn10Ca/MSU-H exhibited better desulfurization performance at 750 °C with a breakthrough sulfur capacity (BSC) of 18.69 g S/100 g sorbent compared to other supported Mn-based sorbents (13.2 g S/100 g sorbent) in similar desulfurization condition, and strong durability in multiple sulfidation-regeneration cycles using oxidation/reduction regeneration method which resolved the scientific issue of that CaSO4 is hardly decomposed to CaO. The introduction of Ca species effectively promoted the dispersion of active constituents, which improved the desulfurization activity. More importantly, 90Mn10Ca/MSU-H showed excellent H2O-resistance ability due to the fact that CaO enhanced the sorption of H2O. Moreover, the utilization of MSU-H with large pore size and excellent thermal stability effectively assured fast mass-transfer and confined the migration of active particles, which led to long lifetime stability of sorbents.Download full-size image

To enhance the stability of sorbents during continuous desulphurization–regeneration cycles, KIT-6 with 3D pore channels was used as a support for the sorbents. A series of mesoporous xLayMn/KIT-6 sorbents with different La/Mn atomic ratios were fabricated using a sol–gel method and their desulphurization properties of hot coal gas were investigated at 700–850 °C. 3La97Mn/KIT-6 performed the best at 800 °C with a breakthrough sulphur capacity of 11.56 g sulphur per 100 g sorbent. The eight successive desulphurization (800 °C)–regeneration (600 °C) cycles revealed that 3La97Mn/KIT-6 with endurable regeneration abilities could retain 80% of the initial sulphur capacity. It indicated a better desulphurization performance compared to pure 3La97Mn and 3La97Mn/MCM-41. The fresh and used xLayMn/KIT-6 sorbents were characterized by means of BET, XRD, HRTEM, XPS and H2-TPR techniques. The XRD patterns and HRTEM images of fresh and used 3La97Mn/KIT-6 verified that the utilization of KIT-6 effectively suppressed the aggregation of Mn2O3 particles and improved the stability of the sorbent.