Fumin Wang

Hydrochlorination of acetylene using supported phosphorus-doped Cu-based catalysts

Phosphorus-doped copper catalysts supported on spherical activated carbon (SAC) were prepared using an incipient wetness impregnation technique. The catalysts were characterized by low-temperature N2 adsorption/desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP), N2O pulse titration method and thermogravimetric (TG) technologies. The results indicate that the phosphorus-doped Cu-based catalysts exhibit both high activity and good stability. The amount of phosphorus dopant has a significant effect on the catalytic activity of acetylene hydrochlorination and the optimal molar ratio of Cu/P is 2.5. The phosphorus doping facilitates the dispersion of copper species, enhances the interaction between metal and support, and restrains the growth of copper species during acetylene hydrochlorination. These results suggest that this high-activity, good-stability and low-cost catalyst has great potential in industrial applications.

Preparation of rGO–mesoporous silica nanosheets as Pickering interfacial catalysts

A series of reduced graphene oxide–mesoporous silica nanoflakes (rGO–MSN) with adjustable surface wettability were developed. Detailed SEM, TEM, XRD, BET, and TGA analyses demonstrated that morphologies, structures, porosities of the obtained composite materials were greatly influenced by rGO content. Moreover, micrographs and conductivity measurements were conducted to investigate the performance of rGO–MSN as emulsifier in stabilizing paraffin/water two-phase system. Furthermore, anchored with –SO3H, the modified hybrid nanoflakes SO3H–rGO–MSN-x% were employed as solid emulsifier and catalyst (Pickering interfacial catalyst) at solvent free oil–oil interface for acetal reaction and showed excellent dodecyl aldehyde conversion more than 90%.

Surface-modified TS-1 with enhanced activity for cyclohexanone ammoximation in a Pickering emulsion and increased stability in hot aqueous ammonia

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.

Synthesis and Characterisation of Hierarchically Porous HZSM-5 as Catalysts for the Synthesis of 2,3,5-Trimethyl-1,4-benzoquinone

Hierarchical HZSM-5 were synthesised by controlled desilication in alkaline medium and characterised by field-emission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, inductively coupled plasma–atomic emission spectrometry, N2 adsorption–desorption, and Fourier transform infrared spectroscopy. The catalytic performance of HZSM-5 towards the selective oxidation of 2,3,6-trimethylphenol by H2O2 was evaluated. Recyclability tests were also carried out. The results showed that 2,3,5-trimethyl-1,4-benzoquinone was produced in high yields (i.e. 90 %), corresponding to a 2,3,6-trimethylphenol percentage of 98 %. The N2 adsorption–desorption and XRD studies suggested that mesopores with an average size of 5 nm were produced and that the structural character of HZSM-5 was preserved after desilication. Transmission electron microscopy analysis of the spent catalyst indicated good stability of the hierarchical structure. The Fourier transform infrared spectroscopy studies revealed the development of acid sites. The combined results suggested that the nature of the solvent, intrinsic acidity, and shape selectivity of the hierarchical structure of the catalyst ensured high catalytic properties.