Synthesis Of High-Stability Mesoporous Aluminosilicates With SDBS/P123 And AOT/P123 Composite Templates

Much attention is being paid to the Mesoporous aluminosilicates due to their high specific surface area and adjustable pore structure.However,the poor hydrothermal stability due to the amorphous structure of the mesophase walls of greatly hinders its application in severe chemical process,such cracking(FCC)of heavy oil.To solve this problem,the authors of the present investigation develop the self-assembly of zeolite Y nanoclusters,which greatly improves the hydrothermal stability of the mesoporous aluminosilicates.Althought much progress has been made on the enchnacement of hydrothermal stability,it is still a great challenge to decrease that consumption of template and water.in this paper,the following research were carried out:(1)MAs were obtained by using the composite template of sodium dodecylbenzene sulfonate(SDBS)and P123.In this strategy,the alkyl chains of SDBS can enter the hydrophobic core of P123 to form a composite micelle with P123,and thus resulting in the repulsion beteen the negative charges of the hydrophilic segment.As a result of this,the agglomeration beteen micelles was inhibited significantly.Moreover,_enhancement of hydrophilicity and dispersibility of the micelles due to the presence of ? bond in SDBS,inhibits the agglomeration of the micelles greatly.This strategy is characterized by the high-concentration template system,decreased consumption of templates(0.74 g P123/g MAs)and water consumption(16.3 g H2O/g MAs).Characterization results indicated that the obtained sample have a surface area of 821.5 m2/g,and pore volume of 0.74 cm3/g after hydrothermal treatment,indicated the high hydrothermal stability by SDBS/P123 strategy.(2)The to-tailed structure of diisooctyl succinate sodium(AOT)is introduced into the high-concentration templates system,and the surfactant is combined with the hydrophobic association of the block copolymer micelle.The hydrocarbon chains of AOT are solubilized into the hydrophobic core of the block copolymer P123 micelles to form P123/AOT mixed micelles.There is also a bonded water layer around AOT head group because water molecules of the hydrated sodium ions tend to hydrogen bond to the negatively charged AOT polar head groups.Under this force,the composite micelles approach the water molecules,increasing the hydrophilicity and dispersibility of the micelles,thereby realizing the formation of mesoporous aluminosilicates in the highconcentration template system,and greatly reducing the consumption of template(0.72 g P123/g MAs)and water consumption(15.2 g H2O/g MAs).Characterization results indicated that the surface area is 350.2 m2/g after hydrothermal treatment at 800? and 100%water vaporization for 10 h.(3)Mother liquor recycling is developed to recycling the remaining reactants(such as Al,Si,template agent)in the mother liquor,resulting in the decreased consumption of water and template.On the basis of these,SDBS/P123 and AOT/P123 are applied to the mother liquor circulation process to synthesize mesoporous aluminosilicates,further reducing the consumption of template and water.