Kev npaj ntawm Macroporous Pseudo Boehmite Nano Cov ntaub ntawv

Nrog rau txoj kev loj hlob sai ntawm kev lag luam tshuaj, alumina, tshwj xeeb tshaj yog mesoporous - Alumina yog dav siv nyob rau hauv ntau cov tshuaj tiv thaiv vim hais tias ntawm nws loj tshwj xeeb cheeb tsam, tshwj xeeb nto thaj chaw thiab cov yam ntxwv stability. Txhawm rau txhawm rau txhim kho cov catalytic efficiency, qhov pore ntim loj thiab siab tshwj xeeb thaj chaw - Kev npaj ntawm alumina yog qhov tseem ceeb dua. - Alumina feem ntau yog npaj los ntawm lub cev qhuav dej ntawm pseudo boehmite ntawm qhov kub thiab txias. Yog li ntawd, nws tuaj yeem hais tias cov cuab yeej ntawm precursor pseudo boehmite txiav txim siab cov khoom - Cov khoom ntawm alumina. Nyob rau hauv daim ntawv no, mesoporous pseudo boehmite tau tsim nyob rau hauv micelles ntawm txawv surfactants, sodium bis (2-}ethylhexyl) succinate sulfonate (AOT), cetyltrimethylammonium bromide (CTAB) thiab polyethylene glycol octyl phentony (10) ether (1. Txoj kev los nag ncaj qha, siv aluminium nitrate hexahydrate li inorganic aluminium qhov chaw thiab ammonia li precipitant. Qhov muaj pes tsawg leeg ntawm cov khoom tau soj ntsuam los ntawm X-ray diffraction (XRD), kis tau tus mob electron microscope (TEM), scanning electron microscope (SEM) thiab N2 adsorption desorption Cov txiaj ntsig tau pom tias fibrous pseudo boehmite nrog lub cheeb ntawm 2-5nm tau npaj rau hauv AOT system, thiab agglomerated granular khoom tau txais hauv Triton X-100 thiab CTAB system. Hauv AOT micelle system, ntshiab pseudo boehmite tuaj yeem npaj tau thaum lub davhlau ya nyob twg pH yog 8 10.5. Tsis tas li ntawd, cov teebmeem ntawm cov hlau ions ntawm cov khoom ntawm cov khoom tau raug kawm. Nws tau pom tias qhov kev taw qhia ntawm cov hlau ions sib txawv tau txhim kho qhov tshwj xeeb ntawm thaj chaw, qhov pore ntim thiab pore txoj kab uas hla ntawm pseudo boehmite. Tsis tas li ntawd, nyob rau hauv triblock polymer polyoxyethylene polyoxypropylene polyoxyethylene (PEO (20) PPO (70) peo (20), P123) thiab anionic surfactant 2 Nano hlau oxide catalyst CuO tau tsim nyob rau hauv cov txheej txheem sib xyaw ntawm sodium ethylhexyl succinate sulfonate (AOT) { {17}} Al2O3, nws qhov kev ua haujlwm catalytic rau epoxidation ntawm styrene tau kawm. Nws tau pom tias cov khoom tseem ceeb ntawm cov tshuaj tiv thaiv catalytic yog benzaldehyde thiab phenylethylene oxide. Cov teebmeem ntawm cov tshuaj tiv thaiv kub, hnyav, molar piv ntawm oxidant rau substrate styrene ntawm kev hloov dua siab tshiab thiab kev xaiv ntawm styrene epoxidation tau tshawb xyuas. Nws tau pom tias CuO- - Al2O3 catalyst muaj kev hloov pauv siab heev (97.43 feem pua) rau styrene epoxidation, thiab kev xaiv ntawm cov khoom epoxidation kuj siab (85.15 feem pua).