•Silica-walled TS-1 colloidosomes were fabricated through an interfacial sol-gel process.•Micron-sized TS-1 colloidosome can be easily recycled by a filtration process.•The prepared TS-1 colloidosome dimension is tailorable according to water-to-oil volume ratio (Rw/o) and ratio of TS-1 wt to oil volume (Rs/o).•The prepared TS-1 colloidosome is catalytically active for liquid-phase alkene epoxidation.Ultrafine hierarchical TS-1 zeolite (<300 nm) generally expresses eminent catalytic activity for liquid-phase alkene epoxidation, but encounters serious separation difficulties. Micron-sized silica-walled TS-1 colloidosomes, which were synthesized via an interfacial sol-gel method, can effectively resolve fine TS-1 zeolite separation problems. The interfacial sol-gel process involves construction of a stable W/O Pickering emulsion stabilized by fine TS-1 particles and alkali-catalyzed hydrolysis of silica precursor methyl-trimethoxysilane at the oil-water interface. The successful preparation of TS-1 colloidosome was verified by Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). The prepared TS-1 colloidosome dimension is tailorable according to water-to-oil volume ratio (Rw/o) and ratio of TS-1 wt to oil volume (Rs/o). On the same time, X-ray diffraction patterns and UV–vis spectra disclosed that the interfacial sol-gel process had no effect on the MFI structure of hierarchical TS-1 particles. The catalytic results showed that the prepared TS-1 colloidosome was a very active and stable catalyst for liquid-phase alkene epoxidation reactions.Micron-sized silica-walled TS-1 colloidosomes were fabricated via an interfacial sol-gel process.Download high-res image (191KB)Download full-size image

•The HDO reaction pathways of guaiacol catalyzed by activated carbon supported molybdenum catalyst were proposed.•Phenolics were selectively converted in the HDO of guaiacol over Mo catalyst.•MoO2/AC and Mo2C/AC were prepared at different reductive temperatures in H2 flow and their catalytic activities were compared.•The effect of solvents on the HDO selectivity of guaiacol was investigated.Activated carbon-supported molybdenum dioxide catalyst and molybdenum carbide catalyst were prepared by reduction in hydrogen with different temperatures. Hydrodeoxygenation (HDO) of guaiacol was investigated in 3 MPa initial H2 pressure with these two catalysts. Phenolics were detected as the main products when catalyzed by molybdenum dioxide catalyst. Through analyzing the HDO selectivity of guaiacol and the intermediates including 1,2-dihydroxy-3-methylbenzene, catechol, phenol and anisole, the HDO reaction pathways of guaiacol over Mo-based catalysts were proposed. In the first stage, transalkylation and breaking of three CO bonds take place to produce 1,2-dihydroxy-3-methylbenzene, catechol, phenol and anisole, whereafter cresol, phenol, toluene and benzene are produced. Furthermore, the effects of reaction temperatures and solvents on HDO of guaiacol were investigated. Using tetralin as solvent, in 3 MPa initial H2 pressure and at 573 K, the conversion of guaiacol reached 98% with phenolics as the major product and the selectivity was greater than 91% after three hours of reaction time.Download full-size image

Effects of water-soluble co-solvents(WSCs)on the properties of water/oil Pickering emulsions were investigated. Pickering emulsions were prepared in the system of 1,2,4-trimethylbenzene(TMB)/ hydrophobic silica/ water with varied concentrations of WSCs(ethanol, acetic acid and glycerin). Mean droplet diameter distributions of the obtained emulsions were studied to investigate the effects of WSCs types and concentrations. The results demonstrated that mean droplet diameter distributions decreased at first and then increased with the increase of WSC concentration. Moreover, the effect of WSC concentration on the phase inversion locus was further investigated. At the same time, infrared radiation(IR)spectrometer was used to investigate the mechanism. The results showed that the WSC attaching on hydrophobic silica changed the wettability of the particles, which facilitated the formation and phase inversion of the emulsion. The hydrogen bonds between the co-solvent groups attaching on the solid particles made a great effect on the droplet size of the emulsion and strengthened the interaction among emulsifiers. Overall, proper WSC was in favor of the stability of Pickering emulsion.

Functional TS-1, partially hydrophobilized with organosilanes, was found to be more active and stable in a Pickering emulsion. In this work, TS-1 behaved simultaneously as a catalyst and solid emulsifier favoring the cyclohexanone ammoximation reaction in organic solvent-free conditions. The composition, structure, formed emulsion morphology, and surface morphology were characterized by Fourier-transform infrared (FT-IR) spectroscopy, conductometer, optical microscope with high speed CCD camera, Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It indicated that hydrophobilization provided TS-1 a moderate wettability, allowing the formation of a stable Pickering emulsion, thus promoting the performance in catalyzing the cyclohexanone/H2O2/NH3·H2O reaction in the absence of organic solvents. What is more, due to alkyl groups grafted to TS-1, the zeolites were comparatively exclusive to the aqueous phase and they are more capable of enduring severe environment, i.e., 200 °C, under autogenic pressure.

TiO2 nanocrystals with diameters 8–10 nm have been prepared through sol–gel method using a mixed template of polyethylene glycol (PEG) and cetytrimethylammonium bromide (CTAB) at low temperature. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution (HR) TEM and fourier transform infrared spectroscopy (FT-IR) etc. XRD analysis showed the TiO2 photocatalysts prepared with mixed template are pure anatase. FTIR spectrum revealed that the cationic surfactant provides CTA+ molecules and bonds to Ti–O to prevent the condensation reaction. PEG plays a dispersant role in controlling the structure of nano-TiO2 particles. CTAB and PEG incorporated with each other to restrain the growth of crystal nucleus and control the size of grain. The self-assembling process has been confirmed by HRTEM. PEG played different role in mixed template from the single template. The photocatalytic activity of samples was determined by using \( 3{\text{I}}^{ - } \to {\text{I}}_{3}^{ - } + 2{\text{e}}^{ - } \) as a model reaction. The results showed that TiO2 photocatalysts with mixed template have higher photocatalytic activity than P25.