| The catalyst applied in selective hydrogenation most common in use is nickel and the next is noble metal, whose outstanding activity and selectivity may compensate its costly price. Phosphonomycin is a new broad antibacterial whose antimicrobial spectrum is more abroad than penicillin and cephalosporins. An industrialized method and a microbiological fermentation method are included. In the industry , the racemic body of phosphonomycin is obtained through total chemical synthesis. Via chemical resolution , phosphonomycin is finally obtained. Six-step reactions are included in the industry synthesis. One step of them is preparing from 1, 2-propadienyl-phosphonic acid with palladium supported by active carbon to cis-1-propenyl phosphonic acid . According to the different of characteristic infrared absorption, also with L-B law, a series of standard graphs are built and a method is set up to analyze the production, as the evaluating indicator. On the foundation of the catalyst now in existence, combining with the factual industry production, the condition of craftwork. temperature, pressure and other factors have been examined. The best reaction condition : temperature is 328K, the pressure is 0.3MPa, the reaction period is about 120 minutes, the stir speed (S.S.) is 1200 turn/min.To investigate the effect of the condition of preparation on the hydrogenated activity, a series of catalysts of palladium supported on active carbon are manufactured through impregnation. The catalyst is assessed through the hydrogenation of acetone on a reactor set by self. As the evaluating indicator of the catalyst, production is achieved through IR analysis. To confirm the effect of the condition of preparation on the activity , orthogonal experiment has been designed with seven factors and three levels. Through the orthogonal experiment, the seriation is made: adsorption temperature> reductant >reducing temperature>pH of reducing>adsorption time>pH of adsorption>reduction time. And the bestpreparation condition finally obtained: the adsorption temperature is 313K; the reductant 10 times; and the reduction temperature is 353K; the pH of reduction is 8.0; the adsorption time is 6 hours: the pH of adsorption is 2; the reduction time is 2 hours.According to the best preparation condition, changing the active components, the type of support, the amount of active component respectively, and a series of catalysts are prepared. After investigating the hydrogenated activity and activity of the catalyst the conclusion is made that the hydrogenated activity is improved greatly but the activity of the catalyst decreases in some degree when Pd is substitute for Ru. So it is concluded that the Ru/C catalysts are suitable for the hydrogenation of acetone reaction and the Pd/'C catalysts are not suitable for the reaction of the conversion of 2-propadienyl-phosphonic acid to cis-1-propenyl phosphonic acid. It is found that the performance of the catalysts is changed, if only the supports are different. It is to say that the performance of the catalysts is affected by the interactivity between the support and the active components.XRD has been done to detect characters of several series of catalysts. It is found that particle sizes of the catalysts whose activities are obviously different directly affected the activities, bigger or smaller are both not perfect. It is also found that the characteristic peak (29is about 40? is not basically obvious and activity is lower when content of Pd is smaller. The activities become higher and higher while the content of Pd gradually becomes more and more, particle sizes of catalysts bigger and bigger. However activity changes little with content of Pd exceeds 5 %.In addition, if remaining the total leaded amount about 5%, and changing the ratio between Pd and Ru, such as 1/3, 1/1, 3/1, a series of double activity catalysts are prepared. As a result, the performance of the catalysts is increasing but the activity of adsorption of hydrogen decreasing with the Pd increasing. The catalysts are... |
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