It is well known that boron exists as polyborate anions in aqueous solution.Boron atom can coordinates to three or four oxygen atoms and borate can exist as not only the monomer but also the polymer.The polymerization
How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with hi...How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe_(2)O_(3) nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe_(2)O_(3) nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.展开更多
基金Financial supports from the NNSFCs (Grants 201276194 and 201306136)the Funds of Tianjin Key Laboratory of Marine Resources and Chemistry in TUST (Grants 201303 and 201206)the Natural Science Fund of TUST (Grant 20130112)
文摘It is well known that boron exists as polyborate anions in aqueous solution.Boron atom can coordinates to three or four oxygen atoms and borate can exist as not only the monomer but also the polymer.The polymerization
基金This work was supported by the National Natural Science Foundation of China(Nos.21978198 and 22002052).
文摘How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe_(2)O_(3) nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe_(2)O_(3) nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.
文摘以木糖醇母液为原料,采用顺序式模拟移动色谱技术纯化木糖醇母液。在制备色谱研究的基础上,研究顺序式模拟移动床(SSMB)技术纯化木糖醇母液的最佳工艺参数。结果表明最佳工艺参数为:进料浓度60%,进料量为546.00 g/h,进水量为819.00 g/h,循环量382.2 m L。在此条件下木糖醇出口浓度为41.2%,纯度达到94.8%,收率达到90.6%,较木糖醇母液纯度提高31.12%,本研究为木糖醇母液产业化利用奠定了实践基础。