XRD and FT-IR methods were applied to the studies of organic monolayer dispersionsystems. Naphthalene, borneol, benzoic acid, salicylic acid, phthalic acid and tartaric acid weremixed with γ-Al2O3 and SiO2 separately...XRD and FT-IR methods were applied to the studies of organic monolayer dispersionsystems. Naphthalene, borneol, benzoic acid, salicylic acid, phthalic acid and tartaric acid weremixed with γ-Al2O3 and SiO2 separately. The results showed that the organic compounds canalso disperse spontaneously onto the surfaces of different oxide-supports to become high dispersionstates like the behavior of inorganic salts and oxides. The organic substances studied are moreready to disperse with 1ess carboxyl or hydroxyl groups on their aromatic nucleus, suggesting themigration on the surface of the support is rate-determining during the dispersion. This point ofview is supported by the result of IR spectroscopy. The IR spectra of dispersed systems suggestthat the carboxy1 may react with the surface hydroxyl groups of the support to form salt-likestructures on the surface.展开更多
The dispersion of urea onto the surface of clinoptilolite was studied. The data of XRD and IR clearly showed that urea can disperse onto the surface of clinoptilolite spontaneously and it has a threshold of 0.12g/g. T...The dispersion of urea onto the surface of clinoptilolite was studied. The data of XRD and IR clearly showed that urea can disperse onto the surface of clinoptilolite spontaneously and it has a threshold of 0.12g/g. The possible interaction between dispersion urea and the surface of clinoptilolite was discussed. This research has promising futural application.展开更多
Five CuCl2/NaY sytems prepared with different methods were studied byXRD. One system is prepared by giving heat treatment to the solid mixture of CuCl2and NaY. The other four systems are all prepared by impregnation m...Five CuCl2/NaY sytems prepared with different methods were studied byXRD. One system is prepared by giving heat treatment to the solid mixture of CuCl2and NaY. The other four systems are all prepared by impregnation methods ,Nay impregnated in CuCl2 solution of absolute alcohol, 0.05 mol·L（- 1） H2SO4, de-ionized waterand 0.1 mol·L-1 HCl respectively. The resuits show that under certain conditons,CuCl2could spontaneously disperse onto the NaY surface. The maximum dispersion capacity（threshold） is much larger than the amounnt of Cu ions exchanged onto NaY surface byion exchange methods. The thresholds are very different according to differe preparation processes. They are subject to two factors: the water adsorbed on NaY surface andthe prior adsorption of HCl on NaY surface. These two factors can markedly reduce thethreshold of CuCl2 on the surface of NaY zeolite. Meanwhile, under certain conditions,the dispersion state of Cu ion NaY surface could be changed obviously. The higher thepH value of NaY zeolite surface and the calcination temperation, the more obvious thehydrolization of CuCl2.展开更多
A Series of LiCl/γ-Al2O3 samples were prepared by mixing and then heating at 400℃ for 30 hours. 7Li MAS NMR was used to investigated their structures. The 7Li MAS NMR signal of LiCl in the dispersion phase was obser...A Series of LiCl/γ-Al2O3 samples were prepared by mixing and then heating at 400℃ for 30 hours. 7Li MAS NMR was used to investigated their structures. The 7Li MAS NMR signal of LiCl in the dispersion phase was observed for the first time, and its chemical shift was at 0.25ppm.After the dispersion threshold of LiCl on γ-Al2O3 was achieved, the 7Li signal in the crystallme phase LiCl appears at -1.01ppm and its intensity increases with the increasing in LiCl loading.From the 2D nutation NMR spectra, it can be seen that the electric field gradient surrounding the lithium nuclei in the dispersion state is larger and so the quadrupole interaction is stonger than that in the crystalline state. The dispersion threshold indicated by NMR is in agreement with that deduced from XRD, which is about 0.136gLiCl/gγ-Al2O3.展开更多
文摘XRD and FT-IR methods were applied to the studies of organic monolayer dispersionsystems. Naphthalene, borneol, benzoic acid, salicylic acid, phthalic acid and tartaric acid weremixed with γ-Al2O3 and SiO2 separately. The results showed that the organic compounds canalso disperse spontaneously onto the surfaces of different oxide-supports to become high dispersionstates like the behavior of inorganic salts and oxides. The organic substances studied are moreready to disperse with 1ess carboxyl or hydroxyl groups on their aromatic nucleus, suggesting themigration on the surface of the support is rate-determining during the dispersion. This point ofview is supported by the result of IR spectroscopy. The IR spectra of dispersed systems suggestthat the carboxy1 may react with the surface hydroxyl groups of the support to form salt-likestructures on the surface.
文摘The dispersion of urea onto the surface of clinoptilolite was studied. The data of XRD and IR clearly showed that urea can disperse onto the surface of clinoptilolite spontaneously and it has a threshold of 0.12g/g. The possible interaction between dispersion urea and the surface of clinoptilolite was discussed. This research has promising futural application.
文摘Five CuCl2/NaY sytems prepared with different methods were studied byXRD. One system is prepared by giving heat treatment to the solid mixture of CuCl2and NaY. The other four systems are all prepared by impregnation methods ,Nay impregnated in CuCl2 solution of absolute alcohol, 0.05 mol·L（- 1） H2SO4, de-ionized waterand 0.1 mol·L-1 HCl respectively. The resuits show that under certain conditons,CuCl2could spontaneously disperse onto the NaY surface. The maximum dispersion capacity（threshold） is much larger than the amounnt of Cu ions exchanged onto NaY surface byion exchange methods. The thresholds are very different according to differe preparation processes. They are subject to two factors: the water adsorbed on NaY surface andthe prior adsorption of HCl on NaY surface. These two factors can markedly reduce thethreshold of CuCl2 on the surface of NaY zeolite. Meanwhile, under certain conditions,the dispersion state of Cu ion NaY surface could be changed obviously. The higher thepH value of NaY zeolite surface and the calcination temperation, the more obvious thehydrolization of CuCl2.
文摘A Series of LiCl/γ-Al2O3 samples were prepared by mixing and then heating at 400℃ for 30 hours. 7Li MAS NMR was used to investigated their structures. The 7Li MAS NMR signal of LiCl in the dispersion phase was observed for the first time, and its chemical shift was at 0.25ppm.After the dispersion threshold of LiCl on γ-Al2O3 was achieved, the 7Li signal in the crystallme phase LiCl appears at -1.01ppm and its intensity increases with the increasing in LiCl loading.From the 2D nutation NMR spectra, it can be seen that the electric field gradient surrounding the lithium nuclei in the dispersion state is larger and so the quadrupole interaction is stonger than that in the crystalline state. The dispersion threshold indicated by NMR is in agreement with that deduced from XRD, which is about 0.136gLiCl/gγ-Al2O3.
