Pure nanocrystalline LaAlO3 powders were synthesized by W/O microemulsion consisting of water, Tween-80 (surfactant), n-Hexyl alcohol (cosurfactant), and cyclohexane (oil). Precursor hydroxides were precipitated in th...Pure nanocrystalline LaAlO3 powders were synthesized by W/O microemulsion consisting of water, Tween-80 (surfactant), n-Hexyl alcohol (cosurfactant), and cyclohexane (oil). Precursor hydroxides were precipitated in the aqueous cores of W/O microemulsions and then separated and calcined to obtain nanocrystalline LaAlO3 powder. The decomposition behavior of the precursors hydroxides were studied by thermogravimetry analysis (TGA). The precursor hydroxides were calcined at different temperatures and the phase evolution was studied by X-ray powder diffraction (XRD). And the morphology of LaAlO3 powder was studied by transmission electron microscopy (TEM). The crystallite size was less than 50 nm and the shape of the particle is approximately spherical.展开更多
In this study,isobutane dehydrogenation to isobutene reaction was carried out in a series of PtCu bimetallic catalysts prepared by coimpregnation method.The catalysts were characterized by means of several techniques,...In this study,isobutane dehydrogenation to isobutene reaction was carried out in a series of PtCu bimetallic catalysts prepared by coimpregnation method.The catalysts were characterized by means of several techniques,including XRD,N_(2) adsorptiondesorption,TEM,XPS,H2TPR and TG.The results show that the existence of LaAlO_(3) perovskite can enhance the dispersion and sintering resistance of metal nanoparticles and facilitate the transfer of carbon deposits from active sites to the support.Interestingly,the perovskite nanoparticles can also inhibit the reduction of CuOx and the formation of PtCu alloys,resulting in the suitable interaction between Pt and Cu.The PtCu/LaAlO_(3)/SiO_(2)catalyst exhibits the optimal dehydrogenation performance with an isobutane conversion of 47%and isobutene selectivity of 92%after 310 min reaction,which was ascribed to the unique role of LaAlO_(3) perovskite as well as the appropriate PtCu interaction.展开更多
基金Natural Science Foundation Project of Chongqing Science and Technology Commission (2005BA4019)
文摘Pure nanocrystalline LaAlO3 powders were synthesized by W/O microemulsion consisting of water, Tween-80 (surfactant), n-Hexyl alcohol (cosurfactant), and cyclohexane (oil). Precursor hydroxides were precipitated in the aqueous cores of W/O microemulsions and then separated and calcined to obtain nanocrystalline LaAlO3 powder. The decomposition behavior of the precursors hydroxides were studied by thermogravimetry analysis (TGA). The precursor hydroxides were calcined at different temperatures and the phase evolution was studied by X-ray powder diffraction (XRD). And the morphology of LaAlO3 powder was studied by transmission electron microscopy (TEM). The crystallite size was less than 50 nm and the shape of the particle is approximately spherical.
基金the National Natural Science Foundation of China(21776214)and State Key Laboratory of Chemical Resource Engineering.
文摘In this study,isobutane dehydrogenation to isobutene reaction was carried out in a series of PtCu bimetallic catalysts prepared by coimpregnation method.The catalysts were characterized by means of several techniques,including XRD,N_(2) adsorptiondesorption,TEM,XPS,H2TPR and TG.The results show that the existence of LaAlO_(3) perovskite can enhance the dispersion and sintering resistance of metal nanoparticles and facilitate the transfer of carbon deposits from active sites to the support.Interestingly,the perovskite nanoparticles can also inhibit the reduction of CuOx and the formation of PtCu alloys,resulting in the suitable interaction between Pt and Cu.The PtCu/LaAlO_(3)/SiO_(2)catalyst exhibits the optimal dehydrogenation performance with an isobutane conversion of 47%and isobutene selectivity of 92%after 310 min reaction,which was ascribed to the unique role of LaAlO_(3) perovskite as well as the appropriate PtCu interaction.
