Preparation Of Hydrophobic Super Solid Acid And Its Catalytic Esterification Study

Homogenous acids such as Lewis acids, protic acids are widely being used inmodern industries. Searching for a kind of novel, environmental friendly andrecyclable heterogenous acid catalyst to substitute the homogenous ones which arecorrosive has caught a lot of attention for the modern chemists.Solid acid catalysts, which belong to heterogenous side, possess the advantages ofhigh catalytic activity, not corrosive, less pollution, recyclable and economic. Solidacid catalysts have already been used in chemical reactions such as esterification,alkylation, hydration and isomerization with more perspective and widespreadapplications in the future. However, there are drawbacks for traditional solid acids.Their active components could be lost during the reactions which produce or involvewater. And for the solid acid catalysts composed by nano-particles, it’s very hard torecover the catalyst after reaction.In this paper, hydrophobic solid acid AC-H₂SO₄-Cnwere prepared byimpregnated with sulfuric acid then with trimethylchlorosilane. The surface of activecarbon was modified by trimethylchlorosilane and subsequently hydrophobic layerwas formed by two chains which are O-Si chain and C-H chain. The structure andmorphology of the catalyst were characterized by FT-IR, XRD and TA-DTG. Influenceof active carbon materials, particle sizes, preparation methods, trimethylchlorosilanedosage and temperature etc. on catalytic activity and hydrophobicity was investigated.The result shows that the catalyst AC-H2SO4-Cnhas high catalytic activity and reusability.And then the catalytic esterification ability of the catalyst using starch as carbonsouce was investigated. Influence of preparation method, calcination temperature,carbonization temperature and catalyst dosage etc. on catalytic activity wasinvestigated. Carbon encapsulated magnetic nano-particle solid acid catalysts wereprepared in order to solve the hard separation problem of the catalyst from the products.FT-IR, SEM and VSM were carried out to characterize the catalyst.