Search

The use of biomass-based glycerol to produce chemicals with high added value is of great significance for solving the problem of glycerol surplus and thus reducing the production cost of biodiesel. The production of 1,2-propanediol (abbreviated as 1,2-PDO) and 1,3-propanediol (abbreviated as 1,3-PDO) via the hydrogenolysis of glycerol is one of the most representative and highest-potential processes for the comprehensive utilization of biomass-based glycerol. Glycerol hydrogenolysis may include several parallel and serial reactions (involving broken C–O and C–C bonds), and therefore, the catalyst is a key factor in improving the rate of glycerol hydrogenolysis and the selectivities of the target products. Over the past 20 years, glycerol hydrogenolysis has been extensively investigated, and until now, the developments of catalysts for glycerol hydrogenolysis have been active research topics. Non-precious metals, including Cu, Ni, and Co, and some precious metals (Ru, Pd, etc.) have been used as the active components of the catalysts for the hydrogenolysis of glycerol to 1,2-PDO, while precious metals such as Pt, Rh, Ru, Pd, and Ir have been used for the catalytic conversion of glycerol to 1,3-PDO. In this article, we focus on reviewing the research progress of the catalyst systems, including Cu-based catalysts and Pt-, Ru-, and Pd-based catalysts for the hydrogenolysis of glycerol to 1,2-PDO, as well as Pt-WOx-based and Ir-ReOx-based catalysts for the hydrogenolysis of glycerol to 1,3-PDO. The influence of the properties of active components and supports, the effects of promoters and additives, and the interaction and synergic effects between active component metals and supports are also examined. [ABSTRACT FROM AUTHOR]

A poly( N -vinyl-2-pyrrolidone) (PVP)-assisted wet impregnation method has been developed for preparing highly-dispersed supported Ni/SBA15-PVP (1/X) catalysts, in which 1/X indicates the molar ratio of PVP polymer to Ni. XRD and TEM results of as-prepared samples showed that PVP addition could dramatically promote the dispersion of NiO on SBA-15, with the n PVP /n Ni ratios in the range of 1/5000–1/1000. Whereas, severe sintering of NiO could be observed on Ni/SBA15-PVP (1/X) catalysts prepared with no PVP (1/X = 0), insufficient PVP (1/X = 1/7500) or superabundant PVP (1/X = 1/100). These catalysts were employed to catalyze the carbon dioxide reforming of methane (CRM) reaction, and the optimized Ni/SBA15-PVP (1/X) catalysts (1/X = 1/5000–1/1000) exhibited much better stability than others during the 25 h test. Besides, the role of PVP addition during the preparation process was illustrated detailedly with Raman, 1 H NMR, UV–vis, FTIR, and TPO characterizations. PVP would interact with Ni(NO 3 ) 2 . 6H 2 O to form complexes through the coordination of the oxygen and nitrogen atoms in the ring of PVP, with Ni 2+ , NO 3 − and H 2 O from the precursor during the drying step. Moreover, this complex could improve the stabilization, inhibit the redistribution and affect the decomposition behavior of the precursor, which ultimately led to a significantly improvement of the NiO dispersion on SBA-15 support. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cu/La2O3 exhibited high catalytic activity for the formation of glycerol carbonate. [•] CH3CN worked as dehydrating reagent to break thermodynamic equilibrium. [•] The Cu metal sites and basic sites of affected the activity Cu/La2O3 significantly. [•] TOF decreased dramatically with the increase in Cu particle size. [ABSTRACT FROM AUTHOR]

The partial oxidation of methane (POM) to syngas has attracted the attentions of scientists in the recent 20-30 years due to the depletion of methane and its obvious advantages. Ni-based catalysts were most widely employed in the POM because of their comparable catalytic performance with noble metal-based catalysts as well as their cheap prices. However, Ni-based catalysts were suffered from carbon deposition and sintering which were the main reasons for catalyst deactivation. Therefore it's necessary to improve the abilities of Ni-based catalysts to resist carbon deposition and sintering. In this review, types of Ni-based catalysts that could be used in the POM to syngas are reviewed and at last, the future of Ni-based catalysts in the POM is discussed. [ABSTRACT FROM AUTHOR]

Abstract: Ni/Y2O3, with Y2O3 support prepared by the conventional precipitation method, was prepared by an impregnation method. The physicochemical properties of Y2O3 and Ni/Y2O3 were characterized by BET, CO2-TPD, NH3-TPD, TPR, XRF and TGA, and compared with those of γ-Al2O3 and Ni/γ-Al2O3, respectively. The catalytic performance of Ni/Y2O3 in the reaction of partial oxidation of methane (POM) to syngas was evaluated and compared with that of Ni/γ-Al2O3 catalyst, too. The results showed that, Y2O3 was a basic support with few acidic sites while γ-Al2O3 was an acidic support. NiO particles supported on Y2O3 were more easily to be reduced than those supported on γ-Al2O3. In the partial oxidation of methane, Ni/Y2O3 catalyst showed high catalytic activity and exhibited better catalytic stability than Ni/γ-Al2O3. After POM reaction at 700 °C for 550 h, methane conversion decreased little and only 2.2 wt% carbon was deposited on Ni/Y2O3 catalyst. Ni/Y2O3 was stable in POM even after a series of reaction temperature variations within the temperature range of 400 ∼ 800 °C. [Copyright &y& Elsevier]

Abstract: Bimetallic Ru–Re/SiO2 and monometallic Ru/SiO2 catalysts were prepared by impregnation method and their catalytic performances were evaluated in the hydrogenolysis of glycerol to propanediols (1,2-propanediol and 1,3-propanediol) with a batch type reactor (autoclave) under the reaction conditions of 160°C, 8.0MPa and 8h. Ru–Re/SiO2 showed much higher activity in the hydrogenolysis of glycerol than Ru/SiO2, and the pretreatment conditions of the catalyst precursors had great influence on the catalytic performance of both Ru–Re/SiO2 and Ru/SiO2 catalysts. The physicochemical properties of Ru–Re/SiO2 and Ru/SiO2, such as specific surface areas, crystal phases, morphologies/microstructures, surface element states, reduction behaviors and dispersion of Ru metal, were characterized by N2 adsorption/desorption, XRD, Raman, TEM–EDX, XPS, H2-TPR and CO chemisorption. The results of XRD, TEM–EDX and CO chemisorption characterizations showed that Re component had an effect on promoting the dispersion of Ru species on the surface of SiO2, and the measurements of H2-TPR revealed that the co-existence of Re and Ru components on SiO2 changed the respective reduction behavior of Re or Ru alone. High pre-reduction temperatures would decrease the activities of Ru–Re/SiO2 and Ru/SiO2 catalysts, compared with the corresponding calcined catalysts (without pre-reduction), which actually went through an in-situ reduction during the reaction. XPS analysis indicated that Ru species was in Ru0 metal state, while Re species was mostly in Re oxide state in the spent Ru–Re/SiO2 sample. Re component was probably in rhenium oxide state rather than Re0 metal state to take part in the reaction via interaction with Ru0 metal. [Copyright &y& Elsevier]

Abstract: ZrO2 supports were prepared by different methods (conventional precipitation method, shortened as “CP”, and alcogel/thermal treated with nitrogen method, shortened as “AN”), and Cu/ZrO2 catalysts were prepared by impregnation method. The supports and catalysts were characterized by BET, XRD, TEM and TPR. The effects of the preparation methods of ZrO2 supports and the treatment conditions (calcination and reduction temperatures) of the catalyst precursors on the texture structures of the supports and catalysts as well as on the catalytic performances of Cu/ZrO2 in CO hydrogenation were investigated. The results showed that the support ZrO2-AN had larger BET specific surface area, cumulative pore volume and average pore size than the support ZrO2-CP. Cu/ZrO2-AN catalysts showed higher CO hydrogenation activity and selectivity of oxygenates (C1–C4 alcohols and dimethyl ether) than Cu/ZrO2-CP catalysts. Calcination and reduction temperatures of supports and catalyst precursors affected the catalytic performance of Cu/ZrO2. The conversion of CO and the STY of oxygenates were 12.7% and 229g/kgh, respectively, over Cu/ZrO2-AN-550 at the conditions of 300°C, 6MPa. [Copyright &y& Elsevier]

Several supported Ru–Re bimetallic catalysts (Ru–Re/SiO2, Ru–Re/ZrO2, Ru–Re/TiO2, Ru–Re/H-β, Ru–Re/H–ZSM5) and Ru monometallic catalysts (Ru/SiO2, Ru/ZrO2, Ru/TiO2, Ru/H-β, Ru/H–ZSM5) were prepared and their catalytic performances were evaluated in the hydrogenolysis of glycerol to propanediols (1,2-propanediol and 1,3-propanediol) with a batch type reactor (autoclave) under the reaction conditions of 160 °C, 8.0 MPa and 8 h. Compared with Ru monometallic catalysts, the Ru–Re bimetallic catalysts showed much higher activity in the hydrogenolysis of glycerol, and Re exhibited obvious promoting effect on the performance of the catalysts. The supported Ru monometallic catalysts and Ru–Re bimetallic catalysts were characterized by N2 adsorption/desorption, XRD, TEM-EDX, H2-TPR and CO chemisorption for obtaining some physicochemical properties of the catalysts, such as specific surface areas, crystal phases, morphologies/microstructure, reduction behaviors and dispersion of Ru metal. The results of XRD and CO chemisorption indicate that the addition of Re component could improve the dispersion of Ru species on supports. The measurements of H2-TPR revealed that the coexistence of Re and Ru components on supports changed the respective reduction behavior of Re or Ru alone on the supports, indicating the existence of synergistic effect between Ru and Re species on the bimetallic catalysts. The hydrogenolysis of some products (such as 1,2-propanediol, 1,3-propanediol, 1-propanol and 2-propanol) were also examined over Ru and Ru–Re catalysts for evaluating influence of Re–Re on the reaction routes during glycerol hydrogenolysis. The results showed that over Ru–Re catalysts, glycerol was favorable to be converted to 1,2-propanediol, but not favorable to ethylene glycol, while 1,2-propanediol and 1,3-propanediol were favorable to be converted to 1-propanol. The influence of glycerol concentration in its aqueous solution on the catalytic performance was also evaluated over Ru and Ru–Re catalysts. [ABSTRACT FROM AUTHOR]

RhCl(CO)(PPh3)2 was anchored to diphenylphosphinopropyl-modified (– PrPPh2) mesoporous silicate MCM-41. Infrared spectroscopy was applied to monitor the multi-step assemble of the complex by assigning critical absorptions. The prepared catalyst was employed in 1-octene hydroformylation and showed high conversion of substrate as well as high selectivity of nonyl aldeydes (>97%) along with several stable catalyst cycles. Rhodium leaching in the reaction liquids was determined by mass spectroscopy, which was found extremely low. The catalyst showed higher activity and lower metal loss than the analogue by nano SiO2 as support, probably as a result of the confining of molecular sieves with ordered pores. [ABSTRACT FROM AUTHOR]

Mesoporous Ce0.5Zr0.5O2 solid solution catalyst was synthesized by a sol-gel process using block copolymer Pluronic P123 as the template. The as-prepared catalyst was characterized by X-ray diffraction, H2-Temperature-programed reduction, BET, and X-ray photoelectron spectra techniques. The catalytic properties of the catalyst were evaluated by the synthesis of iso-C4 hydrocarbons via CO hydrogenation. The mesoporous catalyst showed much better catalytic selectivity and yield of isobutene and isobutane (i-C4) from CO hydrogenation at 673–723 K, 5.0 MPa, and 720 h−1, than the solid Ce0.5Zr0.5O2 catalyst prepared by coprecipitation. This was due to the higher BET surface area, pore volume and the reducibility of the mesoporous Ce0.5Zr0.5O2 catalyst. [ABSTRACT FROM AUTHOR]

Abstract: Ru/Al2O3, Ru/C and Ru/ZrO2 catalysts were applied to the hydrogenolysis of glycerol to propanediol, and the effect of Re as an additive on the catalytic performance of Ru catalysts was examined. The catalyst systems were characterized by N2 adsorption/desorption, XRD, TEM-EDX and XPS. The hydrogenolysis of glycerol was carried out under the conditions of 120–180°C, 4–10MPa hydrogen pressure and 4–8h, and the conversion of glycerol varied from 18.7% to 29.7% over Ru/Al2O3, Ru/C and Ru/ZrO2 catalysts. The reaction results indicate that Re possesses high promoting effect on the catalytic performance of Ru catalysts in glycerol hydrogenolysis. [Copyright &y& Elsevier]

Abstract: CeO2–TiO2 (Ce:Ti=0.25–9, molar ratio) catalysts were synthesized by a sol–gel method and the catalytic performances were evaluated in the selective synthesis of isobutene and isobutane from CO hydrogenation under the reaction conditions of 673–748K, 1–5MPa and 720–3000h−1. The physical properties, such as specific surface area, cumulative pore volume, average pore diameter, crystal phase and size, of the catalysts were characterized by N2 adsorption/desorption and XRD. All the CeO2–TiO2 composite oxides showed higher surface areas than pure TiO2 and CeO2. No TiO2 phase was detected on the samples of CeO2–TiO2 in which TiO2 contents were in the range of 10–50mol%. Crystalline Ce2O3 was detected in CeO2–TiO2 (8:2). The reaction conditions, temperature, pressure and space velocity, had obvious influences on the CO conversion and distribution of the products over CeO2–TiO2 (8:2) catalyst. [Copyright &y& Elsevier]

Abstract: The effects of CO2 on the selective formation of i-C4 hydrocarbons (isobutene and isobutane) from CO2/CO/H2 reactant mixtures were studied. Three ZrO2-based catalysts including unmodified ZrO2, 8.6%Y2O3-ZrO2, and 15.3%Al2O3-0.5%K2O-ZrO2, were used in this study. The catalysts were characterized by N2 adsorption, X-ray diffraction (XRD), Raman, spectra, temperature-programmed desorption (TPD) of ammonia and carbon dioxide, and temperature-programmed reduction (TPR). The influences of CO2 on the catalytic performances of the catalysts were investigated by varying the content of CO2 in the feed up to 20%. It was found that the addition of CO2 in the synthesis gas (CO/H2) significantly reduced the net formation of CO2, but did not affect the formation of hydrocarbons. For the distribution of hydrocarbons, the selectivity to i-C4 in total hydrocarbons decreased with increasing the content of CO2 in the feed, while the selectivities to C1–C3 hydrocarbons increased. However, the i-C4 selectivities in all products were enhanced significantly because of the inhibition of CO2 formation with CO2 adding in the feed. The predominant products in CO2 hydrogenation on the ZrO2-based catalysts were CO and H2O at 648–723K, indicating that the ZrO2-based catalysts were not active in the reactions towards hydrocarbons from CO2/H2. A 5–6% yield of i-C4 hydrocarbons with ∼62% selectivity in the products was achieved on 15.3%Al2O3-0.5%K2O-ZrO2 catalyst at 8–9% CO conversion with 20% CO2 adding in the feed at 698K. The yield of CO2 was only 0.5% (∼5% CO2 selectivity in the products). Our results would suggest one potential way of using the recycle of CO2 formed to selectively synthesize i-C4 hydrocarbons from coal or natural gas-derived syngas (CO+H2) with high carbon efficiency (with free or very low CO2 emission). [Copyright &y& Elsevier]

Abstract: Sm2O3 doped ZrO2-based catalysts (Sm2O3–ZrO2 composite oxide) were prepared by co-precipitation and their physical properties (texture and structure) and chemical properties (acid–base and redox) were characterized with the methods of N2 adsorption–desorption isotherm, powder X-ray diffraction, Raman spectroscopy, NH3 and CO2 temperature programmed desorption and H2 temperature programmed reduction. The catalytic performances of the catalysts (activity and selectivities) were evaluated in the CO hydrogenation to isobutene and isobutane (isosynthesis) under the reaction conditions of 673K, 5.0MPa, and 650h−1. The relationship between the catalytic performance and the physical/chemical properties of Sm2O3–ZrO2 catalysts were also examined. The catalytic activity and selectivity of the Sm2O3–ZrO2 catalysts varied with Sm2O3 doping. The physical properties of the catalysts, such as cumulative pore volumes, average pore diameters and crystal sizes had some influences on the activity and selectivity in the isosynthesis. CO conversion increased with an increase in the amount of the acidic sites on the surface of Sm2O3–ZrO2 catalysts, while iso-C4 percentage in total hydrocarbons increased with an increase in the amount of the basic sites. The addition of Sm2O3 into ZrO2 enhanced the reducibility of Sm2O3–ZrO2 catalysts. The highest CO conversion (21.6%) and C4 selectivity (41.8%) were obtained over the catalyst that had a maximum amount of H2 consumptions (57.7μmolg−1) in the TPR measurement for Sm2O3–ZrO2 catalysts. A coordination of the acid–base properties and the redox property may play important role for the improvement of the catalytic performances of the isosynthesis. [Copyright &y& Elsevier]

The effect of reactor materials on the catalytic performance of the isosynthesis was investigated. Al2O3 and several calcium salts promoted zirconium dioxide-based catalysts were prepared by mechanical mixing method and evaluated in the isosynthesis reaction in a quartz-lined stainless-steel tubular reactor and a stainless-steel tubular reactor, respectively. It was found that stainless-steel tubular reactor seriously affected the selectivity of isosynthesis, while quartz-lined stainless-steel tubular reactor was favorable for the formation of i-C4 hydrocarbons and suppressing the formation of CO2. The addition of Al2O3 into ZrO2 could largely enhance the activity while maintain the i-C4 selectivity of pure ZrO2. CaF2 or CaSO4, as an additive promoted the formation of i-C4, in the meantime maintains the activity of pure ZrO2. The influence of reaction temperatures on the catalytic performance of the catalysts in the quartz-lined stainless-steel tubular reactor was also investigated. [Copyright &y& Elsevier]

ZrO2-based catalysts doped with CeO2 or Y2O3 were prepared by coprecipitation and the catalytic performance of each was evaluated in the selective synthesis of isobutene and isobutane (i-C4) from CO hydrogenation at 673 K, 5.0 MPa, and 650 h−1. The physical properties and chemical properties (acid–base and redox) of the catalysts were systematically characterized and related to the catalytic performance. The catalytic activities and selectivities of the ZrO2-based catalysts varied with the quantity of CeO2 and Y2O3 doped. The physical properties, such as surface areas, cumulative pore volumes, average pore diameters, crystal phases, and crystal sizes had no appreciable effects on the catalytic performance of the catalysts. Temperature-programmed reduction (TPR) of H2 measurements showed that the addition of CeO2 or Y2O3 into ZrO2 enhanced the reduction properties of the catalysts. The highest activities and C4 selectivities in total hydrocarbons were obtained over the catalysts which have a maximum amount of H2 consumption measured by TPR technology for both CeO2- and Y2O3-doped ZrO2-based catalysts. The selectivity to i-C4 in total hydrocarbons also achieved a maximum over the catalyst (50% CeO2-doped ZrO2) which has a maximum amount of H2 consumption in the TPR for the CeO2–ZrO2 mixed oxide catalysts. For the Y2O3–ZrO2 mixed oxide catalysts, high selectivities to i-C4 in total hydrocarbons were obtained over the catalysts with the contents of doped Y2O3 ranging from 4.5 to 8.6%; whereas the maximum H2 consumption was attained at 8.6% Y2O3 doped. The acid–base properties also played a significant role in determining the activity and selectivity of the ZrO2-based catalysts in the CO hydrogenation. A coordination of redox and acid–base properties accounts for the remarkable improvement of reaction activities and selectivities over the CeO2- or Y2O3-doped ZrO2-based catalysts in this investigation. [Copyright &y& Elsevier]

The effect of reactor materials on the catalytic performance of the isosynthesis was investigated. Al2O3 and several calcium salts promoted zirconium dioxide based catalysts were prepared by mechanical mixing method and evaluated in the isosynthesis reaction in a quartz lined stainless steel tubular reactor and a stainless steel tubular reactor, respectively. It was found that stainless steel tubular reactor seriously affected the selectivity of isosynthesis, while quartz lined stainless steel tubular reactor was favorable for the formation of i-C4 hydrocarbons and suppressing the formation of CO2. The addition of Al2O3 into ZrO2 could largely enhance the activity while maintain the i-C4 selectivity of pure ZrO2. CaF2 or CaSO4 as an additive promoted the formation of i-C4 in the meantime maintain the activity of pure ZrO2. The influence of reaction temperatures on the catalytic performance of the catalysts in the quartz lined stainless steel tubular reactor was also investigated. [Copyright &y& Elsevier]

The effect of inorganic ammonium salts which contain group VIB metals of the periodic table (ammonium chromate, ammonium dichromate, ammonium molybdate and ammonium tungstate) as additives on the catalytic performance of Rh catalysts for the hydroformylation of C8-olefins and 1-dodecylene has been investigated. Modification of rhodium with ammonium salts could increase the yield of aldehydes in the hydroformylation of the olefins without phosphine oxide or phosphine ligands and also decrease Rh loss in the distillation process for the separation of the products from the catalyst. [Copyright &y& Elsevier]

Zirconium dioxide based catalysts were synthesized by mechanical mixing method and evaluated for the direct synthesis of isobutene and isobutane (i-C4) from CO hydrogenation. The experiments of temperature-programmed desorption of ammonia and carbon dioxide indicated that both the amount of acid–base sites and the strength of acid and base of the catalysts varied with the incorporation of promoters including various calcium salts, Al2O3 and KOH in ZrO2. The test results indicated that the activity and selectivity of the zirconia based catalysts depended on the acid–base properties of the catalysts. An appropriate amount of moderately strong acid–base sites and ratio of basic to acidic sites on the catalysts are significant for an active catalyst to selectively produce isobutene and isobutane from CO hydrogenation. [Copyright &y& Elsevier]

The non-catalytic and catalytic oxidations of CH4 over Mo–V–Cr–Bi–Si oxide catalysts were investigated in a tubular reactor and the catalysts were characterized by XRD, XPS and TPR. Contents of Bi in the catalysts influenced the combination of Mo–V–Bi–O species and, consequently, influenced the TPR reduction temperature of the catalysts. The catalysts exhibited more selective production of methanol when the TPR reduction peaks shifted to lower temperature. [Copyright &y& Elsevier]

Cu-ZnO/Al2O3 catalyst was examined for the enhancement of methanol selectivity in the products of the direct selective oxidation of methane with O2 and NO in the gas-phase. The precise study of effects of reaction pressures and CH4/O2 ratio on the yield of CH3OH was performed with the Cu-ZnO/Al2O3 catalyst. The yield of CH3OH had a maximum value at 0.4 MPa and CH4/O2=8.0. The yield of CH3OH was enhanced with the Cu-ZnO/Al2O3 catalyst in all of the examined regions. [Copyright &y& Elsevier]

Enhancement of methanol selectivity in the products of the direct selective oxidation of methane with CH4-O2-NO in a gas-phase reaction was examined using a Cu-ZnO/SiO2 catalyst. Two types of Cu-ZnO/SiO2 catalysts were prepared with different compositions: 3:7:90 (denoted as CZS-1) and 5:5:90 (CZS-2) as the weight percent ratios of CuO:ZnO:SiO2. Both CH3OH and CH2O were observed as C1-oxygenates at 550 °C in the gas-phase selective oxidation of CH4 in CH4-O2-NO without a catalyst, but then only CH3OH was observed in the presence of the CZS-1, in addition to the direct gas-phase selective oxidation of methane. The catalyst temperature was 250 °C and the reaction pressure was 0.4 MPa. CH3OH, CO and CO2 selectivities increased and CH2O selectivity decreased in the presence of the Cu-ZnO/SiO2, in comparison to the values in the absence of the catalyst. We, therefore, suggested that three reactions: i.e. the hydrogenation reaction of CH2O, the dissociation reaction of CH2O, and the WGSR, progressed simultaneously on the Cu-ZnO/SiO2 catalyst in CH4-O2-NO.Since the selectivity of CH3OH did not vary during the variation of reaction temperatures from 150 °C up to 350 °C over the Cu-ZnO/SiO2 catalyst, we assumed that SiO2 was a favorable support to enhance the selectivity of CH3OH in a wider catalyst temperature region. [Copyright &y& Elsevier]

Gas phase partial oxidation of methane to methanol has been carried out in a specially designed reactor. A comparatively high yield of methanol (ca. 7–8%, methanol selectivity of 60% at methane conversion 13%) was obtained over a quite wide temperature range of more than 40 °C at 5.0 MPa and CH4/O2/N2=100/10/10 (ml/min). The effects of the total flow rate, CH4/O2 ratio and pressure were examined and the superiority of the new reactor is discussed. [Copyright &y& Elsevier]

Background. Hair follicles are important accessory organs of the skin, and it is important for skin renewal and performs variety of important functions. Diabetes can cause several dermatoses; however, its effect on hair follicles is unclear. The purpose of this study was to investigate the effect of type II diabetes (T2DM) on the hair follicles of mice. Methods. Seven-week-old male C57BL/6 littermate mice were divided into two groups. The treatment group was injected with streptozotocin (STZ) to induce T2DM, and the control group was parallelly injected with the same dose of buffer. Seven days after injection, the back is depilated to observe the hair follicle regeneration. Hair follicle regeneration was observed by naked eyes and HE staining. The proliferation of the skin cells was observed by PCNA and K14 staining. The altered genes were screened by RNA sequencing and verified by qRT-PCR. In addition, Lgr5 + GFP/mTmG transgenic mice were used to observe the effect of T2DM on Lgr5 hair follicle stem cells (HFSC). And the expression of WNT4 and WNT8A were measured by Western Blot. Results. T2DM inhibited hair follicle regeneration. Compared to control mice, T2DM mice had smaller hair follicles, reduced skin thickness, and less expression of PCNA and K14. RNA sequencing showed that the two groups had significant differences in cell cycle and proliferation-related pathways. Compared with the control mice, the mRNA expression of Lgr4, Lgr5, Wnt4, and Wnt8a was decreased in the T2DM group. Moreover, T2DM inhibited the activation of Lgr5 HFSC and the expression of WNT4 and WNT8A. Conclusions. T2DM inhibited hair follicle regeneration and skin cells proliferation by inhibiting WNT-dependent Lgr5 HFSC activation. This may be an important reason for the reduction of skin renewal ability and the formation of chronic wounds caused by diabetes. It is important for the treatment of chronic diabetic wounds and the development of tissue engineering. [ABSTRACT FROM AUTHOR]

Background: Observational studies have shown that matrix metalloproteinases (MMPs) are associated with sepsis. However, it is unknown whether this association represents a causal relationship. Methods: Mendelian randomization (MR) analysis was conducted to assess the potential causal role of circulating MMPs in sepsis. Single nucleotide polymorphisms (SNPs) associated with circulating MMPs levels were used as instrumental variables (IVs). In a sepsis genome-wide association study comprising 1573 cases and 454,775 European ancestry controls, we examined these IVs' effects using a two-sample MR study. Causal estimates were calculated using inverse variance weighting (IVW), the weighted median method, and MR-Egger analysis. Results: Genetically predict that MMP-1 (OR = 1.011, 95% CI 0.772–1.325, p = 0.936), MMP-3 (OR = 1.036, 95% CI 0.862–1.244, p = 0.707), MMP-7 (OR = 1.206, 95% CI 0.960–1.515, p = 0.108), MMP-8 (OR = 1.041, 95% CI 0.949–1.144, p = 0.395), MMP-9 (OR = 1.101, 95% CI 0.831–1.458, p = 0.503), MMP-10 (OR = 1.028, 95% CI 0.840–1.260, p = 0.789) was not associated with the risk of sepsis. Conclusions: The MR study does not provide evidence that circulating levels of MMPs (1, 3, 7, 8, 9, 10) were the causes of sepsis. [ABSTRACT FROM AUTHOR]

The trans-esterification of glycerol and dimethyl carbonate (DMC) for the synthesis of glycerol carbonate was investigated over a series of Li-La 2 O 3 catalysts with different Li contents under mild reaction conditions. Li-La 2 O 3 catalysts were prepared by simple precipitation and impregnation methods, and characterized using ICP, XRD, BET, XPS, CO 2 -TPD and TEM techniques. It was found that the basicity of La 2 O 3 was obviously changed and the interaction between Li and La 2 O 3 occurred after doping Li component, and the catalytic activity of Li-La 2 O 3 was highly relevant to the strength and content of basic sites on the catalysts. Li doping influenced the crystal phase growth of La 2 O 3 , and also changed the exposed crystal planes of the Li-La 2 O 3 catalysts. The highest catalytic performance was obtained over 3.50Li-La 2 O 3 catalyst calcined at 600 °C for 5 h. The glycerol conversion of 94.4% and glycerol carbonate selectivity of 92.1% were obtained over this catalyst under the proper reaction conditions of 85 °C, 3 h, and the molar ratio of glycerol and DMC being 1/3 with using 0.1 g 3.50Li-La 2 O 3 catalyst. [ABSTRACT FROM AUTHOR]

Ni/Y2O3 catalysts, with Y2O3 prepared by the conventional precipitation method and calcined at different temperatures, were characterized by BET, TPR, XRD, NH3-TPD, CO2-TPD and TGA, and evaluated in the reaction of partial oxidation of methane. The results showed that, cubic phase Y2O3 could be obtained by calcinating the precursor at temperatures higher than 500°C, and the specific surface area of Y2O3 was the largest when the calcination temperature was 500°C. NH3-TPD and CO2-TPD profiles showed that, calcination temperature of Y2O3 influenced the amount of acidic and basic sites over Y2O3 support. After the loading of Ni, the strength and the amount of basic sites were almost the same over all the Ni/Y2O3 catalysts, which might be due to the hydrolysis of Y2O3 in the aqueous solution during the impregnation process. TPR results showed that, Y2O3 could be partially reduced, and the interactions between Ni and Y2O3 increased with the increase of Y2O3 calcination temperatures. In the reaction of partial oxidation of methane, all the Ni/Y2O3 catalysts were stable and exhibited high anti-carbon deposition ability. [ABSTRACT FROM AUTHOR]

Background: Only limited data are available on the real-life clinical utilization of aerosolized medications in intensive care unit (ICU) patients. Exploring the utilization of aerosolized medications in the ICU may contribute to develop appropriate education and improve the quality of aerosol therapy. Methods: A 2-week, prospective, multicenter, observational, cohort study was conducted to record how the aerosolized medications were utilized in the Chinese ICUs, including indications, medications used in solo or combination, dosage, and side-effects in adult patients. Results: A total of 1006 patients from 28 ICUs were enrolled, of which 389 (38.7%) received aerosol therapy. The most common indications for aerosol therapy were difficulty in secretion management (23.1%) and chronic obstructive pulmonary disease exacerbation (18.5%). The combination of inhaled corticosteroids and short-acting muscarinic antagonist was the most commonly used medication (19.5%, 76/389). Ninety-two percent (358/389) of the patients did not have any side effects during aerosol therapy. More patients in the group with mechanical ventilation received bronchodilators than spontaneous breathing patients (81.3% vs. 55.5%, p < 0.001), and more patients who breathed spontaneously through a tracheostomy received mucus-regulating agents than other patients (70% vs. 37.9%, p = 0.004). Conclusion: In mainland China, more than one-third of adult ICU patients received aerosol therapy. Medications utilized during aerosol therapy were variable in patients with different respiratory support. To promote appropriate use of aerosolized medications, high-quality randomized, controlled trials and clinical guidance on aerosolized medication indications and dosing are needed to improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Abstract: RhCl3 was immobilized to diphenylphosphinopropyl (–PrPPh2)-modified mesoporous silica SBA-15 through a multi-step-assembly process. The prepared catalyst was characterized with reference to bulky and surface properties by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), isothermal nitrogen sorption analysis and X-ray photoelectron spectroscopy (XPS). The metal content was determined by inductive coupling plasma-atomic emission spectroscopy (ICP-AES). The prepared rhodium-immobilized catalyst was employed in hydroformylation of several higher olefins of different lengths (C6, C8, and C10), different Csitions (terminal or internal) or different structures (linear or branched). The substrate influences on the activity and recycling stability of the immobilized catalyst were investigated and are discussed. Shorter linear olefin substrates were more easily activated with higher catalyst specific activity, while the catalyst showed recycling stability in hydroformylation of longer and branched olefin substrates. For comparison, PPh3 was externally added to immobilize RhCl3 to –PrPPh2-modified SBA-15. The immobilized catalyst so prepared showed a more flexible immobilizing structure and revealed a promoted turnover number of substrates. [Copyright &y& Elsevier]

An amorphous Co-B catalyst was prepared by chemical reduction method and characterized by isothermal N2 adsorption/desorption, XRD, ICP-AES and HR-TEM. The catalytic activity of the Co-B catalyst in the hydroformylation of 1-octene was evaluated in a 100 mL stainless autoclave. Fresh amorphous Co-B catalyst showed a relatively high activity in the hydroformylation of 1-octene. The thermal stability of fresh Co-B catalyst was also examined. When fresh Co-B catalyst was thermally treated in N2 or H2 atmosphere at 200–500 °C for 2 h, the specific surface area and the catalytic activity of the Co-B catalyst decreased. When Co-B was supported on SiO2, the activity of the catalyst increased obviously. Compared with conventional supported Co/SiO2 catalyst, Co-B/SiO2 showed much higher activity than Co/SiO2. The influences of solvents and reaction conditions on the catalytic activity of the amorphous Co-B catalyst were also studied. The recycle test of the amorphous Co-B catalyst was done. [ABSTRACT FROM AUTHOR]

Abstract: Isosynthesis is referred to the reaction that selectively converts syn-gas (CO+H2) to i-C4 hydrocarbons. Sm2O3 catalysts were prepared using a sol–gel technique with changing preparing parameters and the structure and textural properties of the catalysts were characterized by N2 adsorption–desorption isotherm, XRD and TEM. The influences of preparation parameters on the physical properties and the catalytic performance of Sm2O3 in isosynthesis were studied. The results showed that the Sm2O3 catalysts had lower activity but higher iso-C4 selectivity in the CO hydrogenation, compared with ZrO2 catalysts. Different preparation parameters had effects on the catalytic performance of Sm2O3 in isosynthesis. The Sm2O3 catalysts prepared by alco-method with highest surface area had the highest activity for iso-C4 formation. [Copyright &y& Elsevier]

Graphical abstract Highlights • Photo-thermal catalytic approach is promising for improving catalyst performance. • ZnWO 4 -ZnO is effective in thermal-driven glycerol carbonylation. • Au loading further enhanced the catalytic performances especially with visible light irradiation. • A strong photo-thermal synergistic effect was observed over x%Au/ZnWO 4 -ZnO for the highly promoted catalytic performance. Abstract Converting glycerol and CO 2 into glycerol carbonate offers a green pathway for utilizing biodiesel by-product glycerol and greenhouse gas CO 2 as well as synthesizing the important chemical compound glycerol carbonate. In this study, for the first time, the abundant visible light was introduced into thermal-driven glycerol carbonylation system, aiming to improve catalyst performance via breaking the thermodynamic equilibrium limitations. Here x%Au/ZnWO 4 -ZnO catalysts were designed for the photo-thermal catalytic system. It was found that, ZnWO 4 -ZnO itself was effective in glycerol carbonylation even under thermal-driven condition, and the loading of plasmonic Au further enhanced the catalytic performances especially with visible light irradiation. The visible light responsivity of the catalysts and reaction temperatures played important roles for the photo-thermal performance of x%Au/ZnWO 4 -ZnO, indicating the strong photo-thermal synergistic effect for the highly promoted catalytic performance. This study suggests the photo-thermal synergistic catalysis is one of efficient approaches for further improving catalytic performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Addition of small amount Co to Ni/SBA15 reduced catalyst carbon deposition in DRM. • 4.5Ni0.5Co showed high performance in the long-term stability test at high pressures. • Co enriched on the surface of NiCo prevented from the sintering of metal particles. • Gradual pressurization to high pressure was better for the catalyst stability in DRM. Abstract The catalytic performance of Ni-Co bi-component catalysts in CO 2 reforming of methane (CRM) under high pressures was studied for obtaining highly stable Ni-based catalysts, which is important for the industrialization of high pressure CRM. A series of 5% (xNiyCo)/SBA-15 catalysts were prepared with a modified co-impregnation method by adding trace amount of β-cyclodextrin (CD) into Ni(NO 3) 2 impregnation solution. The effects of catalyst compositions (Ni/Co ratio) and the CRM reaction conditions (pressure, gas hourly space velocity, time on stream, etc) on the catalysts stabilities were investigated. The carbon deposition behaviors of the catalysts during the high pressure CRM reaction were disclosed through detailed characterizations of the spent catalysts. The type of coke, instead of the amount of deposited carbon, was proved to be responsible for the deactivation of 5% (xNiyCo)/SBA-15 catalysts during the high pressure reaction. The amount of carbon deposition depended strongly on the Co loading in the bimetallic catalysts. Long-term stability with 100 h TOS at 2.0 MPa and 800 °C was achieved for the optimized 5% (4.5Ni0.5Co)/SBA-15 catalyst and a slow deactivation (decrease in CH 4 conversion) was observed. The reaction results with different reaction time over 5% (4.5Ni0.5Co)/SBA-15 at high pressures suggested that the accumulation of carbon deposition took place mainly at the initial stage of the CRM reaction. Moreover, the disorder degree of deposited carbon species and the sintering of metal particles were identified as the primary reasons for the deactivation of the catalysts. Trace Co enriched on Ni-Co surface of 5% (4.5Ni0.5Co)/SBA-15 suppressed Ni aggregation and facilitated the adsorption of co-reactant. [ABSTRACT FROM AUTHOR]

Abstract Ce 1-x Zr x O 2 (0 ≤ x ≤ 0.2) solid solutions were prepared by hydrothermal method and applied for the synthesis of glycerol carbonate from glycerol and CO 2 in the presence of 2-cyanopyridine (dehydrant) with dimethyl formamide (DMF) as a solvent. The physicochemical properties of the catalysts were characterized by ICP, XRD, BET, H 2 -TPR, CO 2 /NH 3 -TPD, TEM and XPS. The activation route of CO 2 and glycerol were measured by DRIFTS and FT-IR. Compared to pure CeO 2 , Ce 1-x Zr x O 2 solid solutions exhibited enhanced activity in the present reaction system, and the improved catalytic activity was associated with the BET surface area and the acid-base properties. DRIFTS results showed that the chelating bidentate carbonate species was the main adsorption pattern for CeO 2 and no striking differences between Ce 0·98 Zr 0·02 O 2 and CeO 2. FT-IR spectra of the spent catalysts revealed that glycerol and 2-cyanopyridine could be activated on CeO 2 -based catalysts, and an ester intermediate was formed for the production of glycerol carbonate. Thus, a plausible mechanism is proposed for the synthesis of glycerol carbonate from glycerol and CO 2 in the presence of 2-cyanopyridine in DMF solvent over CeO 2 -based catalysts. Moreover, the recyclability of Ce 0·98 Zr 0·02 O 2 was measured and the catalysts could be regenerated through a simple calcination process at 400 °C for 5 h in air. Graphical abstract Image 1 Highlights • Doping of Zr improved the activity of CeO 2 in carbonylation of glycerol with CO 2 to GLC. • 2-cyanopyridine is an excellent dehydrant for shifting the reaction equilibrium to GLC side. • Activity of Ce 1-x Zr x O 2 was influenced by BET surface area and acid-base properties. • Glycerol and CO 2 could both be activated on CeO 2 -based catalysts in a certain way. [ABSTRACT FROM AUTHOR]

Pd-Re/SBA-15 catalysts with different Pd precursors were prepared by the impregnation method. N 2 adsorption-desorption, XRD, H 2 -TPR, TEM and NH 3 -TPD were used to characterize the physical and chemical properties of the catalysts. Pd-Re catalysts with different precursors showed different activities in the reaction of glycerol hydrogenolysis. 5Pd-5Re/SBA-15 with PdCl 2 as Pd precursor had higher activity than those with Pd(NO 3 ) 2 and Pd(OAc) 2 as precursors. The existence of Cl could affect the particle sizes, reduction behaviors and the acid properties of Pd-Re catalysts. [ABSTRACT FROM AUTHOR]

P123 (PEG-PPG-PEG triblock copolymer) was employed as a modifying agent to prepare highly-dispersed Ni/SBA-15 via a simple wetness impregnation method. A detailed molecular-level pathway had been illuminated to interpret the role of P123 during the catalyst preparation process with Raman, 1 H-NMR, UV–Vis, DLS, FTIR, and TPO measurements. There existed no interaction between Ni(NO 3 ) 2 ·6H 2 O and P123 during impregnation and evaporation steps with the existence of H 2 O in the media. The oxygen atoms of PEO blocks would coordinate with Ni 2+ , NO 3 − and H 2 O to form crown-ether-type complexes when the water was evaporated out from the solution during the drying step, which improved the dispersion and stabilization of the precursor. And the complexes ultimately inhibited the redistribution and affected the decomposition of Ni(NO 3 ) 2 ·6H 2 O precursor during calcination. All in all, the above specific interaction between Ni(NO 3 ) 2 ·6H 2 O and P123 would lead to a critical influence of P123 addition on the NiO dispersion on the support. [ABSTRACT FROM AUTHOR]

The synthesis of glycerol carbonylation with CO 2 to glycerol carbonate over CeO 2 catalyst was investigated. CeO 2 with different morphologies was prepared by traditional precipitation (TP), hydrothermal (TH) and citrate sol-gel (SG) methods, and the reaction of glycerol with CO 2 was carried out in the presence of a dehydrating agent and solvent. The effect of preparation methods of CeO 2 and reaction parameters on the activity and selectivity of the catalysts were examined. The structures, morphologies and surface properties of the catalysts were characterized by XRD, TEM, BET, CO 2 -TPD, H 2 -TPR, Raman and XPS. CeO 2 exhibited high catalytic activity for the formation of glycerol carbonate under mild reaction conditions. The carbonylation of glycerol was influenced by the redox property of CeO 2 . The effects of different types of dehydrating agent and solvent were also studied. The dehydrating agent (2-cyanopyridine) and solvent (Dimethyl Formamide(DMF)) contributed to the increase of glycerol conversion and the yield of glycerol carbonate. The yield of glycerol carbonate could reach as high as 78.9%, and the catalysts could be easily regenerated by calcination at 400 °C for 5 h without loss of activity after 5 recycling times. The proper reaction conditions were 150 °C, 4 MPa and 5 h. [ABSTRACT FROM AUTHOR]

Ni/SBA15-P123 (1/X) catalysts were prepared via a simple and novel P123 (PEG-PPG-PEG triblock copolymer)-assisted wet impregnation method, in which 1/X indicates the molar ratio of P123 to Ni. Various techniques including N 2 physisorption, ICP, XRD, TEM, XPS, TGA-DSC and Raman were employed to characterize the physicochemical properties of the catalysts. The catalytic performances of Ni/SBA15-P123 (1/X) catalysts in carbon dioxide reforming of methane to syngas were evaluated with a vertical fixed-bed quartz tube reactor. XRD and TEM characterization results of as-prepared samples revealed that the Ni dispersions of Ni/SBA15-P123 (1/X) catalysts were dramatically improved with n P123 /n Ni ratios in the range of 1/500- 1/50. Significant improvement of the catalytic performances for the above optimum catalysts can be clearly explicated by comparing with those catalysts prepared with no P123, insufficient P123 (1/X = 1/750) or superabundant P123 (1/X = 1/5). That is, Ni/SBA15-P123 (1/500), Ni/SBA15-P123 (1/100) and Ni/SBA15-P123 (1/50) catalysts exhibited better stability, higher activity and less carbon deposition during the 50 h CRM reaction. [ABSTRACT FROM AUTHOR]

Ni@SiO 2 -yolk–shell catalyst was prepared by the method of etching Ni@SiO 2 -core–shell with hydrochloric acid, while the core–shell catalyst was prepared by the stöber method. In comparison, Ni–SiO 2 –AE (without yolk–shell structure) was used to denote the catalyst prepared by the similar method as Ni@SiO 2 -yolk–shell but without fully encapsulation of Ni particles by SiO 2 . The catalytic performances of these three catalysts were investigated in carbon dioxide reforming of methane to syngas (CRM). The reaction was conducted under different conditions by varying GHSVs of reactants and reaction temperatures to further test the stability of the catalysts. The properties of the as-prepared and spent Ni@SiO 2 -yolk–shell, Ni@SiO 2 -core–shell and Ni–SiO 2 –AE catalysts were characterized by TEM/HRTEM, XRD, TG-DSC to measure the morphology, crystallinity and carbon deposition, etc. It was found that compared to Ni@SiO 2 -core–shell and Ni–SiO 2 –AE catalysts, Ni@SiO 2 -yolk–shell catalyst behaved remarkably stable performance at the temperature up to 1073 K, and the specific structure and carbon deposition-resisted behavior of the Ni@SiO 2 -yolk–shell catalyst may help to maintain the stability during the reaction. [ABSTRACT FROM AUTHOR]

• 20%Co 3 O 4 -ZnO recorded 5.3% glycerol carbonate yield at 150 °C and visible light irradiation. • Basic properties influenced on the performance of xCo 3 O 4 -ZnO under thermal-driven conditions. • Optical properties of xCo 3 O 4 -ZnO were crucial for the activity enhancements under light irradiation. Transforming CO 2 and biomass-based glycerol into glycerol carbonate is an economical and green process. However, this reaction is thermodynamically unfavorable. Breaking the thermodynamic limitation is the key to accelerate the reaction. In this study, a photo-thermal catalytic system was established and a series of low-cost xCo 3 O 4 -ZnO p-n heterojunction catalysts were prepared. It was discovered that 20%Co 3 O 4 -ZnO gave the best photo-thermal performance, recording a glycerol carbonate yield of 5.3% under the conditions of 0.50 g catalyst, 10 mmol glycerol, 5 MPa CO 2 , 20 mL DMF, reaction time 6 h, 150 °C and a 225 W visible light irradiation. Both light and heat were regarded to contribute to the photo-thermal catalytic system. Under thermal-driven conditions, the performance of xCo 3 O 4 -ZnO was influenced significantly by the strength and quantity of basic sites on catalyst surface, while the visible light harvesting capacity as well as the electron-hole separation and migration efficiency were crucial for their activity enhancements under light irradiation. This study is predicted to provide an avenue to construct photo-thermal catalysts for glycerol conversion reactions. [ABSTRACT FROM AUTHOR]

Ag/13X adsorbents were synthesized, characterized and tested for decontamination of gaseous effluents from I at high temperatures. X-ray diffraction patterns showed that the Ag/13X samples maintained a stable structure after calcined at 650 °C for 2 h. The decontamination factors achieved with 15 % Ag/13X and 20 % Ag/13X adsorbents for I were nearly close to 10 at 650 °C. In addition, 15 % Ag/13X had a stable performance for removal of I at 550 and 650 °C, even after calcined at 550 and 650 °C for over 10 h, which might be suitable for future potential use during nuclear reactor operation or in the case of nuclear accidents. [ABSTRACT FROM AUTHOR]

Mesoporous silica MCM-41 supported Ni-based catalysts were prepared by glucose (Glu) and β-cyclodextrin (βCD) modified impregnation method, respectively. The physicochemical properties of the catalysts (Ni/MCM-41-βCD and Ni/MCM-41-Glu) were characterized with BET, XRD, H 2 -TPR and TEM techniques, and their catalytic performance in CO 2 reforming of methane to syngas was evaluated. The results revealed that the prepared catalysts remained the ordered mesoporous structures of MCM-41, and no obvious NiO particles could be viewed on catalysts prepared with β-cyclodextrin or glucose modified method. In contrast, on the catalyst prepared with the conventional impregnation method (Ni/MCM-41), large NiO particles could be observed. In the reaction of CO 2 reforming of methane to syngas, compared with Ni/MCM-41, Ni/MCM-41-βCD and Ni/MCM-41-Glu exhibited higher catalytic activities and better catalytic stabilities. [ABSTRACT FROM AUTHOR]

A kind of typical metal-organic frameworks (MOFs) material, HKUST-1 was prepared by hydrothermal method and characterized by XRD and SEM. The results of characterizations manifested that HKUST-1 showed a regular octahedral crystal structure. The as-prepared HKUST-1 was modified by several kinds of organic base materials and the 2 adsorption behaviors of modified HKUST-1 materials were evaluated. The 2 adsorption capacities of different base modified HKUST-1 varied with the base intensity of modified organic base materials. [ABSTRACT FROM AUTHOR]

Highlights: [•] ·Ru catalysts with HZSM5(X) were used during glycerol hydrogenolysis. [•] ·As the acid amount increased, the glycerol conversion and CH4 selectivity increased. [•] ·The acid amount and acid strength of HZSM5(X) affected the C C bond cleavage. [•] ·Loading Ru on HZSM5(X) could modulate the acidity and decrease CH4 selectivity. [ABSTRACT FROM AUTHOR]

Abstract: Ni/SBA-15-CD(1/X) catalysts were prepared by the impregnation of a certain amount of Ni(NO3)2 and various contents of β-cyclodextrin (CD), in which 1/X indicates the molar ratio of CD to Ni. The physicochemical properties of the catalysts were characterized by BET, XRD, TEM, TPR and TGA, and their catalytic performance in the CO2 reforming of methane to syngas was evaluated using a fixed-bed quartz reactor. The characterization results revealed that Ni/SBA-15-CD(1/X) prepared with n(CD)/n(Ni) ratios in the range of 1/66–1/33 possessed smaller NiO particles and exhibited stronger interactions between NiO and SBA-15, whereas NiO particles were not well-dispersed on Ni/SBA-15-CD(1/X) catalysts prepared with further CD addition (1/X = 1/8 and 1/1). The reaction results indicated that the better-dispersed Ni/SBA-15-CD(1/X) catalysts, such as Ni/SBA-15-CD(1/66), Ni/SBA-15-CD(1/50) and Ni/SBA-15-CD(1/33), exhibited higher conversions and stronger abilities to resist carbon deposition. Regarding the role of CD in dispersing Ni particles, it could be speculated that complexes were formed between CD and Ni2+, as well as NO3 −, which would change the state of Ni species during the impregnation and heat treatment processes. [Copyright &y& Elsevier]

Abstract: Ni/SBA-15 catalysts were prepared by two different methods; conventional impregnation method (Ni/SBA-15) and β-cyclodextrin (CD) modified impregnation method (Ni/SBA-15-CD). The physicochemical properties and the catalytic performance of the catalysts in carbon dioxide reforming of methane (CRM) were compared. Results showed that Ni particles were smaller and better dispersed on Ni/SBA-15-CD, and the interactions between Ni and SBA-15 were stronger. Compared with Ni/SBA-15, Ni/SBA-15-CD exhibited higher catalytic activity and stability in CRM. Post-reaction analysis revealed that CD was effective indirectly in resisting carbon deposition and maintaining the ordered structure of Ni/SBA-15-CD. [Copyright &y& Elsevier]

Abstract: Co3O4 nanoparticles were prepared from cobalt nitrate that was accommodated in the pores of a metal-organic framework (MOF) ZIF-8 (Zn(MeIM)2, MeIM=2-methylimidazole) by using a simple liquid-phase method. The ZIF-8 host was removed by pyrolysis under air and subsequently washing with an NH4Cl–NH3·H2O aqueous solution. Transmission electron microscopy (TEM) analysis shows that the obtained Co3O4 is composed of separate nanoparticles with a mean size of 18nm. The Co3O4 nanoparticles exhibit excellent catalytic activity, cycling stability, and long-term stability in the low temperature CO oxidation. [Copyright &y& Elsevier]