ZnO/SiO\-2 and ZnO\|SiO\-2 catalysts were prepared by the impregnation and sol\|gel method, respectively. The characterization of the catalysts by XPS and FTIR indicated that much "free" zinc oxide and unrea...ZnO/SiO\-2 and ZnO\|SiO\-2 catalysts were prepared by the impregnation and sol\|gel method, respectively. The characterization of the catalysts by XPS and FTIR indicated that much "free" zinc oxide and unreacted Si\_OH existed on the surface of ZnO/SiO\-2 sample. As for ZnO\|SiO\-2 sol\|gel catalyst, the corresponding phenomena were not observed. The prepared samples were also used as the catalysts for decomposition of 2\|butanol. A high selectivity for dehydrogenation was observed over the supported catalyst. However, a high selectivity for dehydration was shown over the ZnO\|SiO\-2 sol\|gel catalyst. The opposite selectivity for dehydration or dehydrogenation observed over the two kinds of catalysts may be just because of the different surface structures of the catalysts.展开更多
Quaternary phosphonium hydroxide(TBPH) is a very effective catalyst for rearrangement polymerization of organosloxanes. Such as octamethylcyclotetrasiloxane, may be polymerized to a linear dimethylsiloxane polymer by ...Quaternary phosphonium hydroxide(TBPH) is a very effective catalyst for rearrangement polymerization of organosloxanes. Such as octamethylcyclotetrasiloxane, may be polymerized to a linear dimethylsiloxane polymer by TBPH. In this paper it was found that this kind of catalysts exhibited a stronger basicity than quaternary ammonium hydroxides for a transient reaction. Methyltetramer polymerized at 90—100 ℃ with about 0.01% of the silanolate of TBPH. TBPH was synthesized and applied in the production of smell-less silicone oil.展开更多
文摘ZnO/SiO\-2 and ZnO\|SiO\-2 catalysts were prepared by the impregnation and sol\|gel method, respectively. The characterization of the catalysts by XPS and FTIR indicated that much "free" zinc oxide and unreacted Si\_OH existed on the surface of ZnO/SiO\-2 sample. As for ZnO\|SiO\-2 sol\|gel catalyst, the corresponding phenomena were not observed. The prepared samples were also used as the catalysts for decomposition of 2\|butanol. A high selectivity for dehydrogenation was observed over the supported catalyst. However, a high selectivity for dehydration was shown over the ZnO\|SiO\-2 sol\|gel catalyst. The opposite selectivity for dehydration or dehydrogenation observed over the two kinds of catalysts may be just because of the different surface structures of the catalysts.
文摘Quaternary phosphonium hydroxide(TBPH) is a very effective catalyst for rearrangement polymerization of organosloxanes. Such as octamethylcyclotetrasiloxane, may be polymerized to a linear dimethylsiloxane polymer by TBPH. In this paper it was found that this kind of catalysts exhibited a stronger basicity than quaternary ammonium hydroxides for a transient reaction. Methyltetramer polymerized at 90—100 ℃ with about 0.01% of the silanolate of TBPH. TBPH was synthesized and applied in the production of smell-less silicone oil.
