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Regeneration has been considered as an ideal way for the post-treatment of waste FCC catalyst (ECat). In this work, the degeneration mechanism of ECat was firstly researched and attributed to the increasing of strong acid sites accessibility of ECat in contrast with fresh FCC catalyst by adsorption FTIR. Based on the proposed degeneration mechanism, ECat was successfully regenerated through suitable weakening for strong acid sites by boron modification. Characterization and evaluation results suggested that, the strong acid sites of regenerated ECat (R-ECat) were apparently decreased by boron modification which had significantly improve the heavy oil catalytic cracking performance of R-ECat. Because of the excellent performance, R-ECat in this work could successfully substitute for partial fresh FCC catalyst in FCC unit, which would provide a practicable way for the reutilization of ECat. [ABSTRACT FROM AUTHOR]

Fluid catalytic cracking (FCC) is still a key process in the modern refining area, in which nickel-contamination for an FCC catalyst could obviously increase the dry gas and coke yields and thus seriously affect the stability of the FCC unit. From the points of surface acidity modification and Ni-passivation, in this paper, a boron-modified FCC catalyst (BM-Cat) was prepared using the in situ addition method with B2O3 as a boron source and emphatically investigated its mechanism and performance of anti-nickel contamination. The mechanism research results suggested that, in calcination, boron could destroy the structure of the Y zeolite and thus decrease the total acid sites and strong acid sites of the Y zeolite from 291.5 and 44.6 μmol·g−1 to 244.2 and 32.1 μmol·g−1, respectively, which could obviously improve the dry gas and coke selectivity of the catalyst and thus enhance the nickel capacity for BM-Cat; on the other hand, under hydrothermal conditions, boron could react with NiO and form into NiB2O4, which could obviously raise the range of the reduction temperature for NiO from 350–600 °C to 650–800 °C and thus promote the nickel-passivation ability for BM-Cat. Therefore, evaluation results of heavy oil catalytic cracking indicated that, under the same nickel-contamination condition, in contrast to the compared catalyst (C-Cat), the dry gas yield, coke yield, and H2/CH4 of BM-Cat obviously decreased by 0.77 percentage points, 2.09 percentage points, and 13.53%, respectively, with light yield and total liquid yield increasing by 3.25 and 2.08 percentage points, respectively, which fully demonstrates the excellent anti-nickel contamination performance of BM-Cat. [ABSTRACT FROM AUTHOR]

Molybdovanadophosphoric anion (H 2 PMo 11 VO 40 2 − ) room temperature ionic liquid was prepared and characterized by the methods of FT-IR and TG. Then, this ionic liquid was employed as catalyst for the oxidation of benzene to phenol by H 2 O 2 without using solvent. The homogeneous emulsion formed by the catalyst and substrates during the reaction facilitated the catalytic process. After reaction, the catalyst could self-precipitate from the reaction media and proved to be recyclable. [ABSTRACT FROM AUTHOR]

High catalytic activity of tungstate intercalated in hydrotalcite-encapsulated magnetic FeO nanoparticles have been prepared. High resolution transmission electron microscopy characterization demonstrated the formation of FeO nanoparticles within LDH matrix with a mean diameter of 1-3 nm. The catalyst of WO/LDH@FeO exhibited excellent catalytic activity for the oxidation of various sulfides. The magnetic properties of the WO/LDH@FeO provided a convenient route for separation of the catalyst from the reaction mixture by application of an external permanent magnet. The spent catalyst could be recycled without appreciable loss of catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Abstract: Basic ionic liquid functionalized mesoporous silica SBA-15 was prepared and characterized by XRD, N2 adsorption–desorption, FT-IR and TEM. The catalyst demonstrated to be an efficient heterogeneous catalyst for olefin epoxidation using H2O2 as oxidant. The catalyst could be recycled at least five times without appreciable loss of catalytic activity. [Copyright &y& Elsevier]

γ-FeO microparticles encapsulated with silica and an outer layer of ordered mesoporous titanium-silica (γ-FeO@nSiO@mTi-Si) were synthesized and used for the epoxidation of olefins. Characterization results showed that this material exhibits a typical core-shell structure with high surface area, narrow pore size distribution and high magnetization. Catalytic activity tests showed that this material presents high activity for the epoxidation of olefins, and the catalyst could be easily recycled and reused for several times. Graphical Abstract: Silica-coated magnetic hematite (γ-FeO) core has been coated with mesoporous titanium-silica shell and used as a magnetically separable heterogeneous catalyst for epoxidation of olefin. This catalyst can be recycled and reused at least five times in the epoxidation of cyclohexene with no major loss of activity. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous, tungsten-containing molecular sieve (W-SBA-15) composites were successfully synthesized via one-step hydrothermal processing using tetraethyl orthosilicate (TEOS) as the silica precursor, sodium tungstate as the tungsten precursor, and pluronic P123 triblock polymer (EO20PO70EO20, Mav =5800) as a structure-directing reagent. The influence of various synthesis factors, such as TEOS/sodium tungstate (Si/W) molar ratios, stirring solution temperatures, TEOS pre-hydrolysis time, and crystallization temperatures, on the structure of the W-SBA-15 composite were investigated. The prepared materials were characterized by using X-ray diffraction (XRD), infrared spectroscopy (IR), diffuse reflectance ultraviolet–visible spectroscopy (DR UV–vis), scanning electron microscopy (SEM), and nitrogen adsorption–desorption measurements. The results showed that all the W-SBA-15 composite materials retained the mesopore structure of SBA-15 and the tungsten oxide species successfully substituted silica in the framework. [Copyright &y& Elsevier]

Superhydrophobic surfaces have shown great potential in various areas such as self-cleaning, anti-icing, drag reduction and biomedical applications. However, it is still challenging to prepare robust superhydrophobic surfaces for real applications. Here, a facile, low-cost dual-sized particle strategy is proposed to fabricate the robust superhydrophobic composite with an "armoured" micro-/nanostructure. As a proof-of-concept, the intrinsically hard quartz sand microparticles (QS MPs) and the epoxy (EP) adhesive are adopted to construct a firm surface frame (EP@QS) as an "armour" to provide mechanical durability while modified superhydrophobic SiO 2 nanoparticles (msSiO 2 NPs) are confined within the cavities among the QS MPs, forming a nanostructure to impart liquid repellency. Benefitting from the strong "armour", the EP@QS@msSiO 2 composite can reserve excellent water repellency after different kinds of environmental test such as cycled mechanical abrasion, ultraviolet radiation treatment, outdoor exposure damage, tape-stripping test, acid-base treatment and NaCl salt solution immersion, temperature treatment and knife scratching. Furthermore, the substrate versatility and nanoparticle versatility of our strategy are explored and verified. By virtue of the structural advantages, these EP@QS@msSiO 2 composite manifest superior self-cleaning property and efficiently directional oil adsorption ability even after mechanochemical damage. Together with robustness and universality, the design strategy of the robust superhydrophobic composite is expected to extend the application scope in harsh nautical applications. We have developed a dual-sized particles strategy for the construction of the robust superhydrophobic composite with an armoured micro-/nanostructure using a facile, low-cost dip coating method. In our design, the QS microstructure frame is firmly fixed by the EP layer as an "armour" to provide the protection for fragile nanostructures from mechanical wear while the SiO 2 nanoparticles modified with a low-surface-energy coating impart the superhydrophobicity. [Display omitted] [ABSTRACT FROM AUTHOR]

The synergistic effect of Zn and Mg can improve the dispersion of Ag on Al 2 O 3 support and increase the proportion of Ag+ and Ag δ n + , which is beneficial to the selective catalytic reduction of NO by propylene. [Display omitted] • Zn and Mg promote the formation of ZnAl 2 O 4 and MgAl 2 O 4 spinels on the surface of γ-Al 2 O 3 carriers. • Inhibits active ingredient agglomeration and improves dispersion. • Facilitates the transitions regulation of Ag+, Ag δ n + and Ag0. • Improved NO conversion, water and sulfur resistance of AgAl catalysts at low temperatures. The effects of Zn and Mg on selective catalytic reduction (SCR) of NO with C 3 H 6 were studied by introducing Zn and Mg into Ag/Al 2 O 3 catalysts with the rotary evaporation method. The effects of Zn and Mg on the microstructure and denitrification performance were characterized by N 2 adsorption–desorption, XRD, UV–vis spectroscopy, H 2 -TPR, NO + O 2 -TPD, XPS and HR-TEM. The results showed that bimetallic Zn and Mg modification increased the proportion of ZnAl 2 O 4 and MgAl 2 O 4 spinels in Ag/Al 2 O 3 catalysts, regulated the dispersion of Ag on the Al 2 O 3 support, and promoted the conversion of Ag0 to active Ag+ and Ag δ n + , which enhanced the NO adsorption capacity and optimized denitrification performance at low temperature. Furthermore, in-situ DRIFTS suggested that enol and acetate generated by C 3 H 6 in the presence of H 2 will react with NO + O 2 to form more –NCO and –CN intermediate species, which facilitated the formation of N 2 and improved N 2 selectivity. Specially, Ag2.5Zn2.5MgAl exhibited more than 95 % NO x conversion, excellent water resistance and sulfur resistance at 300 °C with GHSV = 100 000 h−1. This process promotes the development of efficient vehicle exhaust treatment technology and the application of related products. [ABSTRACT FROM AUTHOR]