Studied On The Supported Amorphous Co-B Catalysts In1-octene Hydroformylation

Recently as the largest homogeneous progress in chemical industry,hydrofomylation of olefins which is the olefins and syngas（CO+H2） reacting forproducing aldehydes and alcohols by the transition metal catalysts, and its productsare broadely used in the production of plasticizers, fabric additives, solvents,surfactants, spices and so on. Commercial catalysts which are employing inhydroformylation are mainly water-soluble rhodium-phosphonite complexes andcobalt complexes in industry. Owing to the low solubility of higher olefin in water,developing excellent prospect, cheap and supported amorphous Co-B catalysts whichcan be reused has important significance. In the present study, with ZrO₂-AN, CNTsand mesoporous SBA-15and so on as supports, supported Co-B catalysts wereprepared by chemical reduction method. The effect of supports and the stabilityduring catalyst recycles on the catalyst activity were investigated.In this paper we have synthesized supported catalyst Co-B/ZrO₂-AN、Co-B/CNTs, Co-B/SBA-15and Co-B/MOF of amorphous alloy byimpregnation-chemical reduction successfully. Gas-phase hydroformylationof1-octene was selected as probe reaction to study on the preparation and thecatalytic activity of the supported amorphous alloy catalyst. During the experimentthe structure、components and surface area etal have been analyzed by X-raydiffraction, N2adsorption analysis, atomic emission spectroscopy, and so on.The result showed that catalytic performances are significantly influenced bycatalyst loading, supports and solvents respectively, and the Co-B/CNTs catalystsexhibited better catalytic properties. In order to explain that, XRD, TEM, ICP wereemployed to investigated their surface nature，followed by discussion about therelationship between catalyst structure and catalytic performances.Results also showed that the supported amorphous Co-B catalyst activity wasincreased with the increasing catalyst loading, also was depended on the support poresize and structure. We found Co leaching during the catalyst recycles, generally is less than7.0%for every supported amorphous Co-B catalysts, the cycle within seveneto ten cycles. The deactivation was attributed to the leaching of the active component,the agglomeration of catalyst particles, the reduction in specific surface area. Thedehydration product which can formed an α,β-unsaturated aldehyde, coverd on theCo-B activecomponent so as to poison the catalysts. After washing with ethanol, theactivity and selectivity of the catalyst were almost completely recovered. This ethanolwashing method prolongs the catalyst life and make the catalyst open up a very goodprospect in industrialization.