分别采用直接(ds)和后合成法(ps)合成含铝的介孔分子筛Al(ds or ps)KIT-1。以钛酸四丁酯Ti(OEt)4为钛源,将钛嫁接在AlKIT-1表面制备出Ti-AlKIT-1样品。用傅里叶变换红外光谱、X射线粉末衍射、固体核磁共振(MAS NMR)、固体紫外-可见漫反...分别采用直接(ds)和后合成法(ps)合成含铝的介孔分子筛Al(ds or ps)KIT-1。以钛酸四丁酯Ti(OEt)4为钛源,将钛嫁接在AlKIT-1表面制备出Ti-AlKIT-1样品。用傅里叶变换红外光谱、X射线粉末衍射、固体核磁共振(MAS NMR)、固体紫外-可见漫反射光谱(DRS)、能谱(EDS)和N2吸附-脱附对样品进行了表征,并以双氧水氧化环己醇为探针考察了样品的催化活性。实验结果表明,分子筛Ti-AlKIT-1具有规整的介孔孔道结构,钛进入介孔分子筛骨架而成为四配位的骨架钛,铝的存在形式与样品AlKIT-1的预处理有关,经铵溶液洗涤的Al(ds)KIT-1中没有非骨架铝。Ti-AlKIT-1在催化双氧水氧化环己醇反应中铝和钛存在明显的协同作用。样品Ti-Al(ds)KIT-1表现出更高的催化作用,这与其具有较高的比表面积、较大的孔容和较高钛铝比有关,80℃反应48 h,重复使用3次后,环己醇的转化率降低至51.3%,仅下降4.31%。展开更多
以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对...以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对苯二酚与叔丁醇的烷基化反应评价样品的催化活性。实验结果表明:样品Al-KIT-1仍保留母体H-KIT-1的介孔结构特征,且铝大多以骨架四面体铝的形式存在。样品的催化活性不仅与其表面酸量有关,而且还与其比表面积和孔容有关。样品Al-KIT-1(20)具有规整的介孔结构,其比表面积和孔容较大,表面酸量较高,表现出最好的催化性能,在150℃下反应4 h,对苯二酚的转化率为78.9%,产物2-叔丁基-1,4-苯二酚和2,6-二叔丁基-1,4-苯二酚的得率分别为9.3%和74.7%。展开更多
Mesoporous molecular series Ti-KIT-1 samples were prepared by three different post-handling methods using Ti(OEt)4 as the Ti source and KIT-1 as the support.The three post-synthetic methods were impregnated method,gra...Mesoporous molecular series Ti-KIT-1 samples were prepared by three different post-handling methods using Ti(OEt)4 as the Ti source and KIT-1 as the support.The three post-synthetic methods were impregnated method,grafting method and colloidal method.The Ti-KIT-1 samples were characterized by FT-IR,DRS,XRD,TG-DSC and physical adsorption-desorption of nitrogen.Experimental results showed that the Ti-KIT-1 samples remained the original mesoporous structure with a smaller specific BET surface area compared to the parent KIT-1 sieve.DRS and FT-IR indicate the existence of tetrahedral titanium(Ⅳ),TG-DSC and chemical analyse method proved that TiO2 weight percentage of grafting sample is much more than impregnated and colloidal samples.The grafting method is a good post-handling method that can effectively make use of a titanium source and promise the original mesoporous structure.展开更多
Mesoporous MSU1 was synthesized from sodium silicate solution and A(EO)9 surfactant in acid media.Compared with synthesis of MSU1 from TEOS,the former had many features such as low cost silica source,nontoxi...Mesoporous MSU1 was synthesized from sodium silicate solution and A(EO)9 surfactant in acid media.Compared with synthesis of MSU1 from TEOS,the former had many features such as low cost silica source,nontoxicity,and short reaction time.Moreover,the products with enhanced shortrange order and narrower pore size distribution were obtained when synthesized in moderate or strong acid media.pH had a large effect on properties of products prepared from sodium silicate solution,such as pore volume,pore wall,pore size and surface area.In near neutral media(pH=608),pore diameter was the smallest and pore wall was the thickest.In the research of two kinds of surfactants(alkylPEO and alkylaryl PEO),system of A(EO)9sodium silicate solution was found good for obtaining products with enhanced shortrange order and narrower pore size distribution.展开更多
文摘分别采用直接(ds)和后合成法(ps)合成含铝的介孔分子筛Al(ds or ps)KIT-1。以钛酸四丁酯Ti(OEt)4为钛源,将钛嫁接在AlKIT-1表面制备出Ti-AlKIT-1样品。用傅里叶变换红外光谱、X射线粉末衍射、固体核磁共振(MAS NMR)、固体紫外-可见漫反射光谱(DRS)、能谱(EDS)和N2吸附-脱附对样品进行了表征,并以双氧水氧化环己醇为探针考察了样品的催化活性。实验结果表明,分子筛Ti-AlKIT-1具有规整的介孔孔道结构,钛进入介孔分子筛骨架而成为四配位的骨架钛,铝的存在形式与样品AlKIT-1的预处理有关,经铵溶液洗涤的Al(ds)KIT-1中没有非骨架铝。Ti-AlKIT-1在催化双氧水氧化环己醇反应中铝和钛存在明显的协同作用。样品Ti-Al(ds)KIT-1表现出更高的催化作用,这与其具有较高的比表面积、较大的孔容和较高钛铝比有关,80℃反应48 h,重复使用3次后,环己醇的转化率降低至51.3%,仅下降4.31%。
文摘以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对苯二酚与叔丁醇的烷基化反应评价样品的催化活性。实验结果表明:样品Al-KIT-1仍保留母体H-KIT-1的介孔结构特征,且铝大多以骨架四面体铝的形式存在。样品的催化活性不仅与其表面酸量有关,而且还与其比表面积和孔容有关。样品Al-KIT-1(20)具有规整的介孔结构,其比表面积和孔容较大,表面酸量较高,表现出最好的催化性能,在150℃下反应4 h,对苯二酚的转化率为78.9%,产物2-叔丁基-1,4-苯二酚和2,6-二叔丁基-1,4-苯二酚的得率分别为9.3%和74.7%。
文摘Mesoporous molecular series Ti-KIT-1 samples were prepared by three different post-handling methods using Ti(OEt)4 as the Ti source and KIT-1 as the support.The three post-synthetic methods were impregnated method,grafting method and colloidal method.The Ti-KIT-1 samples were characterized by FT-IR,DRS,XRD,TG-DSC and physical adsorption-desorption of nitrogen.Experimental results showed that the Ti-KIT-1 samples remained the original mesoporous structure with a smaller specific BET surface area compared to the parent KIT-1 sieve.DRS and FT-IR indicate the existence of tetrahedral titanium(Ⅳ),TG-DSC and chemical analyse method proved that TiO2 weight percentage of grafting sample is much more than impregnated and colloidal samples.The grafting method is a good post-handling method that can effectively make use of a titanium source and promise the original mesoporous structure.
文摘Mesoporous MSU1 was synthesized from sodium silicate solution and A(EO)9 surfactant in acid media.Compared with synthesis of MSU1 from TEOS,the former had many features such as low cost silica source,nontoxicity,and short reaction time.Moreover,the products with enhanced shortrange order and narrower pore size distribution were obtained when synthesized in moderate or strong acid media.pH had a large effect on properties of products prepared from sodium silicate solution,such as pore volume,pore wall,pore size and surface area.In near neutral media(pH=608),pore diameter was the smallest and pore wall was the thickest.In the research of two kinds of surfactants(alkylPEO and alkylaryl PEO),system of A(EO)9sodium silicate solution was found good for obtaining products with enhanced shortrange order and narrower pore size distribution.
