Research Of Carbon Dioxide Capture And Electrochemical Reduction

Zeolite-based molecular sieves are widely used in adsorption and catalysis due to their unique structure and properties.By combining the excellent mass transfer effect of mesoporous with the advantages of high crystallinity of zeolite,hierarchically zeolite molecular sieves improved the adsorption and catalytic properties.This paper focuses on the green construction of hierarchically pore structure of zeolites and its application in naphthalene hydrogenation and the structure control,catalytic application and green synthesis process of new zeolite-based molecular sieves are studied.(1)A kind of long chain alkyl and double quaternary ammonium salt surfactant is designed as the structure designing agent(SDA)to synthesize zeolite with multilayered MFI structure.This zeolite has both micropore and mesopore structure,which also has higher specific surface area(567.44 m2/g)and N2 adsorption(567.44 cm3/g)than ZSM-5 zeolite with ordinary MFI structure.The influence of Si/Al ratio on the crystallization of zeolite is investigated by changing the ratio of Si/Al and not changing the organic structure designing agent.The molecular sieve likes a ball with a diameter of about 4-5 ?m.It shows a clear and ideal lamellar morphology.With the increase of Si/Al ratio,the morphology of the zeolite synthesized changes from spherical cluster shape to spherical lamellar shape and the lamellar structure became thinner and thinner.(2)The newly synthesized zeolite is extracted by supercritical fluid extraction(SFE)as a method removing SDA,and the influence of extraction conditions on extraction efficiency is investigated.Under the conditions of extraction(35 MPa,85?,CO2 flow rate of 1.0 ml/min and methanol flow rate of 0.1?2.0 ml/min)for 3 hours,the maximum extraction efficiency was 65%,and the synthesis effect of zeolite is guaranteed.The operation process is green,energy-saving and environmentally friendly.(3)A bifunction catalyst is synthesized by taking SOD zeolite as core and coating an alumina layer on the basis of supported novel metal Pt.The zeolite has both microporous and mesoporous structures,and it is applied to the catalytic reaction of naphthalene hydrogenation.The presence of micropores effectively protects Pt particles from being poisoned,and the mesoporous structure enhances the mass transfer in the reaction process.Finally,it achieves a selectivity of more than 75%and long life.