Supported H3PW12O40 (HPW) and supported Cesium-Substituted dodecatungsto-phosphate are eco-friendly solid acid catalysts. A series of different loading H3PW12O40/SiO2 and HPW/diatomite were prepared by a typical incipient wetness impregnation of methanol, meanwhile SiO2 and diatomite supported Cs-salt catalysts were prepared via two-step impregnating method. The catalysts were investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The results indicate that the Keggin structure of HPW is intact in the SiO2-supported HPW and SiO2-supported CsHPW. HPW and CsHPW are highly dispersed in the SiO2 at the low loading, while the loading is more than 40% the catalyst grains increase and gather on the surface of the carrier. What's more, diatomite is not a suitable support. HPW and CsHPW have better distribution in the SiO2 than in the diatomite. The activity of catalyst was tested in probe experiment of the alkylation of thiopene (TH) with 1-hexene.
The Ni-Mo-P amorphous catalysts were prepared by chemical reduction method under different sonication conditions. The catalytic performance of the prepared catalysts in selective hydrogenation of nitrobenzene(NB) to aniline(AN) were characterized by XRD, BET, N2-adsorption, H2-TPR and H2-TPD. The results show that the introduction of ultrasonic can improve the dispersion of the active sites in the catalyst, the particle size of the catalyst is also smaller than the regular prepared Ni-Mo-P amorphous catalyst. And the influences of the sonication power and time on the catalysts were discussed and compared. The optimal sonication condition is 70 W within 25 min, its optimal reaction time is 150 min.
Antimony doped tin oxide (ATO) nanoparticles were synthesized via complex-homogeneous coprecipitation. Then different drying methods (such as azeotropic distillation, infrared drying and microwave drying, etc.) were used to eliminate the agglomeration. The nanoparticles were characterized by thermal analysis, X-ray diffraction (XRD), and Brunauer-Emmett-Teller measurements (BET). The result shows that ATO nanopaticles with tetragonal rutile phase structure are all well crystallized after the drying processes above, and the average grain size is between 29.30 nm and 71.52 nm. The grain size estimated by BET method is similar to the result of Scherrer equation, and the nanoparticles prepared by azeotropic distillation have better crystallinity comparing to other methods. With the extension of the distillation time, the grain size increases, and the colour changes from grey blue to light grey. Moreover, the combination of azeotropic distillation and infrared drying can prepare smaller and better crystalline ATO nanoparticles.
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