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Synthesis, Characterization And Application Of Lanthanum Acetic Acid Salt Modified MCM-41

Posted on:2013-09-21Degree:MasterType:Thesis
Country:ChinaCandidate:Y L ZhaoFull Text:PDF
GTID:2231330374996617Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
A series of different Si/La (mole) of the LaAc/MCM-41(LaAcM) mesoporous molecularsieve and Si/Ce (mole) of the CeAC/MCM-41(CeACM) mesoporous molecular sieve wasprepared through microwave scattering. The crystal structure and surface property ofmole-cular sieve were characterized by the XRD, IR, and N2adsorption desorption and so on.the acid intensity and the amount of acid centre are measured by Hammett method, and thesynthesis of Rosin resin was used as aprobe reaction to study the catalytic activity of catalyst.The result is that the catalyst crystal, volume, and specific surface area, pore diameter size hasbeen a substantial impact by different load to bear of mesoporous molecular sieve,the specificsurface area is consistent with the amount of acid centre and affects the activity of catalyst.The results showed that loadded n (Si): n (La)=30:1.0, ICP and organic elementalanalysis showed that the grafting yield were4.51%of La(w%) for LaACM respectively. TheBET surface area of LaACM was972.4m2·g-1with the pore volume of0.7619cm3·g-1andpore size of2.728nm. Organic acid group content of LaACM was0.20mmol/g by Hammett.Loadded n (Si): n (Ce)=30:1.0, ICP and organic elemental analysis showed that the graftingyield were3.04%of Ce(w%) for CeACM respectively. The BET surface area of CeACM was933m2·g-1with the pore volume of0.5873cm3·g-1and pore size of2.571nm. Organic acidgroup content of LaACM was0.22mmol/g by Hammett.The process for rosin esterification reactions using LaAcM and CeAcM were studied, andthrough the measurement of alcohol hydroxyl value method of its formation ester quantitativeanalysis of the yield. The results showed that both of LaAcM and CeAcM molecular sievehad high catalytic activity in rosin esterification reactions. When n (alcohol): n (acid)=1.0:1.0, the reaction time for5h and the amount of catalyst (w%)=4%, the esterificationyield of LaAcM and CeAcM reached92%and88%respectively. The reuse of LaAcM andCeAcM molecular sieve was researched respectively. When the catalysts were used five timesrepeatly, the esterification yield of the former was still approach73%, the esterification yieldof the latter was65%.
Keywords/Search Tags:Acetic acid lanthanum, Acetic acid cerium, Microwave scattering, Loaded, Mesoporous molecular sieve
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