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A feasible approach was developed for the synthesis of ordered mesoporous SBA-15-type materials using coal fly ash (CFA) as raw material. In the proposed approach, CFA was, firstly, activated by subcritical water with the addition of NaOH, which allowed an efficient extraction of silicon species from CFA under strong acidic conditions at near room temperature. Subsequently, in the synthesis system, using silicon extraction solution as the silicon precursor, the introduction of anhydrous ethanol as a co-solvent effectively inhibited the polymerization of silanol species and promoted their collaborative self-assembly with surfactant molecules by enhancing the hydrogen bond interactions. The resultant SBA-15 material had a high purity, high specific surface area (1014 m2/g) and pore volume (1.08 cm3/g), and a highly ordered mesostructure, and, therefore, exhibited an excellent removal efficiency (90.5%) and adsorption capacity (160.8 mg/g) for methylene blue (MB) from simulated wastewater. Additionally, the generation of surface acid sites from the homogenous incorporation of Al atoms onto the mesoporous walls of SBA-15 combined with the perfect retention of the ordered mesostructure endowed the obtained Al-SBA-15 material with a further boost in the removal performance of MB. The MB removal efficiency can reach ~100%, along with a maximum adsorption capacity of 190.1 mg/g. [ABSTRACT FROM AUTHOR]

Catalytic performance of Al‐MCM‐41‐supported vanadia catalysts (V/Al‐MCM‐41) with different V loading was investigated for oxidative dehydrogenation of ethylbenzene to styrene (ST) with CO2 (CO2‐ODEB). For comparison, pure silica MCM‐41 was also used as support for vanadia catalyst. The catalysts were characterized by N2 adsorption, X‐ray diffraction (XRD) pyridine‐Fourier‐transform infrared spectroscopy, H2‐temperature‐programmed reduction, thermogravimetric analysis (TGA), UV‐Raman, and diffuse reflectance (DR) UV–vis spectroscopy. The results indicate that the catalytic behavior and the nature of V species depend strongly on the V loading and the support properties. Compared with the MCM‐41‐supported catalyst, the Al‐MCM‐41‐supported vanadia catalyst exhibits much higher catalytic activity and stability along with a high ST selectivity (>98%). The superior catalytic performance of the present V/Al‐MCM‐41 catalyst can be attributed to the Al‐MCM‐41 support being more favorable for the high dispersion of V species and the stabilization of active V5+ species. Together with the characterization results of XRD, TGA, and DR UV–Vis spectroscopy, the deep reduction of V5+ into V3+ during CO2‐ODEB is the main reason for the deactivation of the supported vanadia catalyst, while the coke deposition has a less important impact on the catalyst stability. [ABSTRACT FROM AUTHOR]

A double-chain quaternary ammonium salt of dioctyl dimethyl ammonium chloride (DDAC8) was first used as a low-cost template to prepare the mesostructured zirconia nanomaterials in an alcohol-thermal system. The material was calcinated to obtain pure tetragonal crystalline zirconia ( t -zirconia) and thus has significantly improved original structure properties, including a narrow pore size distribution of 4–7 nm and a high surface area of 195 m 2 /g. The t -zirconia hierarchical nanoparticle aggregate material is different from the smooth microsphere material obtained using the single chain quaternary ammonium salt template. The characteristic rough surface morphology results from the grid distribution form of the DDAC8 micelles in the ethanol solution and caused the formation of more defect sites, which demonstrate the potential for possible catalytic applications. A formation mechanism of the mesoporous zirconia nanomaterial in the alcohol-thermal system of the surfactants is reasonably explained. The synthesis system may provide a new approach to the preparation of mesoporous nanomaterials. [ABSTRACT FROM AUTHOR]

The super-microporous microcrystalline MgO-ZrO 2 nanomaterials (pore size 1–2 nm) was prepared successfully via a facile one-pot evaporation-induced self-assembly (EISA) method and employed in the transesterification of soybean oil and methanol. X-ray diffraction, transmission electron microscope, temperature programmed desorption of CO 2 , and N 2 adsorption porosimetry were employed to characterize the nanocomposites. Nitrogen sorption isotherms revealed that these materials had large surface areas of more than 200 m 2 /g. Moreover, the sample with a Mg/Zr molar ratio of 0.5 and calcined at 400 °C showed high biodiesel yield (around 99% at 150 °C). [ABSTRACT FROM AUTHOR]

Abstract: The activity and stability of the Co-Beta catalyst were investigated for the selective catalytic reduction (SCR) of NO by CH4 with and without the presence of SO2. The Co-Beta catalyst exhibited good stability during a long-term test of 30h for the SCR reaction in the absence of SO2. The addition of 78ppm SO2 caused a decrease in NO conversion, but the loss of catalytic activity was completely reversible after removal of SO2 from the feed. The characterization of fresh and used Co-Beta catalyst samples by XRD, UV–vis spectroscopy, H2-TPR, NO-TPD and FTIR spectroscopy was carried out to study the effect of SO2 on Co sites. UV–vis spectroscopy and H2-TPR analyses showed that the main Co species present in the catalyst were negligibly reducible Co2+ ions located at ion exchange sites and easily reducible polynuclear and/or nanosized Co oxide phases. The poisoning effects of SO2 on the different Co species were different. The poisoning of SO2 was irreversible for the Co2+ ions at the exchange sites but was completely reversible for the polynuclear and/or nanosized Co oxide species. The reversible deactivation was strongly related to the redox properties of the surface Co species. The polynuclear and/or nanosized Co oxide species were found to be active sites in the SCR reaction. [Copyright &y& Elsevier]

In this work, a highly crystallized SSZ-13 (STM-24) was successfully synthesized with sodium silicate as silica source in the co-existence of seeds and a small amount of N,N,N- trimethyl-1-adamantanamine hydroxide (TMAdaOH, TMAdaOH/SiO 2 = 0.02). The TMAdaOH amount is about one-seventh of that used in the conventional synthesis method. The SSZ-13 samples synthesized by this method were characterized by XRD, SEM, N 2 adsorption/desorption, ICP, FT-IR, UV-Raman, NH 3 -TPD, 27Al and 29Si NMR, and compared with SSZ-13 synthesized by conventional method at TMAdaOH/SiO 2 = 0.14 (TMA-0.14-48). The results show that STM-24 and TMA-0.14-48 have comparable textural properties and acidity, except STM-24 shows a smaller particle size than TMA-0.14-48. Moreover, the SiO 2 /Al 2 O 3 ratios of SSZ-13 synthesized by this method are controllable in a wide range of 7.3–21.5. The synergistic effect between seeds and a small amount TMAdaOH is the key to successful synthesis of SSZ-13. Additionally, Cu-STM-24 and Cu-TMA-0.14-48 catalysts show similar catalytic performances in SCR reaction. The synthesis method reported in this work provides a new and alternative way for a low-cost and efficient synthesis of SSZ-13. [Display omitted] • SSZ-13 was synthesized in the presence of seeds and a small amount of TMAdaOH. • TMAdaOH amount in this method is just 1/7 of that used in the conventional method. • There is a synergistic effect between the seeds and a small amount TMAdaOH. • The synergistic effect is the key to successful synthesis of SSZ-13. [ABSTRACT FROM AUTHOR]