The STudy Of Preparation Of Supported Catalysts In The Supercritical Fluid

Supports of the supported catalysts are particularly important.They can be used as skeletons of active components, disperse active components, provide a suitable pore structure, mechanical properties and thermal stability for the catalysts.In addition, they can provide active sites and enhance catalytic activity and selectivity,save precious metals and so on.Purposeful modification of supports can effectively use active components to improve the catalytic activity and selectivity. The modification of supports, in particular the modification of activated carbons have been studied a lot in past years.The modification of activated carbons can be divided into oxidative modification, reduction of modification, modified by microwave, ultrasonic treatment, plasma modification and so on. However, the modification of the supercritical fluid has not seen the relevant reports.The Supercritical Fluid Deposition has been attended in recent years. But the solubility of inorganic metal precursors in supercritical carbon dioxide usually is low compare to expensive organometallic precursors. The study of inorganic metal precursors and cosolvents is rarely reported in Supercritical Fluid Deposition.The preparation of Ru/C catalysts for the hydrogenation of glucose in Supercritical Fluid Deposition has not been reported. The study in this paper bases on the above research issues.In this paper, the fact that supercritical fluids have modified activated carbons has been found in the process of the preparation of supported catalysts.The study on modified supports by supercritical fluids indiates that supercritical fluids can modify the pore structure.Different supercritical fluids and different supercritical conditions can adjust the pore structure of supports.Modified activated carbons by supercritical fluids supported precious metals Ru for hydrogenation reaction for glucose.The study indiates that catalysts which modified activated carbons by supercritical fluids supported Ru have higher catalytic activity compared to untreater carbon supported Ru. The distribution of active component on the support is more uniform. The interaction between the active component and the support is strengthened. Finally, Experiments which Al2O3 adsorbed inorganic metal precursor Cu(NO3)2 in supercrtical carbon dioxide were carried out. The results show that the adsorption of Cu(NO3)2 on Al2O3 is more compare to conventional impregnation. The distribution of Cu is more uniform.It suggests that inorganic metal precursors and solvents can replace organometallic precursors in the supercritical impregnation.