Nanometric sodium hydride (NaH) possesses a large specific surfacr area. Its chemical reactivity is in orders of inagnitude higher than that of the conmercial one. After heat treatment at 2ll℃, the specific surface a...Nanometric sodium hydride (NaH) possesses a large specific surfacr area. Its chemical reactivity is in orders of inagnitude higher than that of the conmercial one. After heat treatment at 2ll℃, the specific surface area of NaH becomes smaller whereas its chemical reactivity is even higher. This fact indicates that the specific surface area of NaH particles is an important but not the only factor for its high reactivity. NaH treated at (400℃, 6h) still retains a specific surface area of 30m2 g-1 and gives fairly high chenncal reactivity.展开更多
By using OCMOSiH\-3(M=Ru, Rh, Pd) as models to imitate the chemisorption of CO on the silica\|supported catalysts, the geometries and frequencies have been performed for the complexes by Gaussian programs, at the B3LY...By using OCMOSiH\-3(M=Ru, Rh, Pd) as models to imitate the chemisorption of CO on the silica\|supported catalysts, the geometries and frequencies have been performed for the complexes by Gaussian programs, at the B3LYP/LANL1DZ level. An influence of the C\_O bond has been studied and the support effects of silica are obtained. The support effects of silica make the CO frequency an upward shift, which means that the weakened degree of C\_O decreases and the bond strength of C\_O increases naturally compared to those of the non\|silica\|supported catalysts. So the products on the silica\|supported catalysts shift to the oxygenates.展开更多
文摘Nanometric sodium hydride (NaH) possesses a large specific surfacr area. Its chemical reactivity is in orders of inagnitude higher than that of the conmercial one. After heat treatment at 2ll℃, the specific surface area of NaH becomes smaller whereas its chemical reactivity is even higher. This fact indicates that the specific surface area of NaH particles is an important but not the only factor for its high reactivity. NaH treated at (400℃, 6h) still retains a specific surface area of 30m2 g-1 and gives fairly high chenncal reactivity.
文摘By using OCMOSiH\-3(M=Ru, Rh, Pd) as models to imitate the chemisorption of CO on the silica\|supported catalysts, the geometries and frequencies have been performed for the complexes by Gaussian programs, at the B3LYP/LANL1DZ level. An influence of the C\_O bond has been studied and the support effects of silica are obtained. The support effects of silica make the CO frequency an upward shift, which means that the weakened degree of C\_O decreases and the bond strength of C\_O increases naturally compared to those of the non\|silica\|supported catalysts. So the products on the silica\|supported catalysts shift to the oxygenates.
