The Preparation And Properties Of The Confined Hollow SiO₂ Intelligent Catalyst With A Double-shelled Structure

Aniline is a lot of chemical reagents,pharmaceutical,pesticide,medicine,dyestuff,important and high molecular polymer and its valuable intermediates,in chemical process,often using the selective hydrogenation of nitrobenzene compounds.Therefore,it has become one of the hot spots in the field of catalysis to explore a kind of catalyst with high reaction efficiency and high selectivity for the hydrogenation of nitrobenzene.However,the metal activity center,which is easy to be reunite,poor stability and difficult to recover in the catalytic process,seriously restricts its further development.Therefore solve the catalysts in the catalytic process prone to some inevitable problems,such as the active center of easy reunion,catalyst recycle,etc.It is the pursuit of researchers to achieve a kind of multi-functional?stereo-selective catalysis chemistry?hydrogenation catalyst,used in hydrogenation of aromatic amine.also can better meet the nitrobenzene hydrogenation reduction preparation of aniline corresponding class product demand.In this paper a kind of double layer hollow silica?SiO₂?as the carrier,make use of the internal and external layer of SiO₂ nano space of metal nanoparticles fixation,preparation of a new type of confined catalyst,the catalyst for its unique and the regulation of the confined space,has the excellent ability of photocatalytic reduction of nitrobenzene.Compared with the traditional supported metal catalysts,the design of the confined catalyst by metal nanoparticles between fixed inside the outer SiO2,can show a good catalytic activity and stability,and at the same time,because of its high surface area and double layer structure,and to improve incident light in catalyst residence time,increase the rate of the latter's light.The photocatalytic reduction of nitrobenzene is proved to be an excellent catalyst for the reduction of nitrobenzene.In the limited domain in order to realize controllable catalytic catalyst,on the basis of further in outer SiO₂ grafting polymerization on the surface of a layer of intelligent polymer materials,developed a kind of smart controllable confined catalyst,the catalyst effectively double SiO₂,metal particles and intelligent polymer as well as a variety of ingredients such as hollow structure and function as a whole,through the use of its synergies,to achieveefficient selective catalytic nitrobenzene reduction.Compared with the catalyst surface load or limit domain,not only improve the ability of the catalytic reduction of nitrobenzene,and more able to nitrobenzene and nitrophenol achieve the"ideal"the stereoselectivity of the catalytic hydrogenation reduction effect.Through the implementation of this thesis research work,the preparation of the structure of a novel intelligent confined catalyst,not only for its better used in nitrobenzene class efficient reductive into corresponding anilines laid a solid foundation,but also can guide the preparation of other types of confined and smart catalyst provided valuable experimental data and theoretical basis.