New Preparation Process Of Catalyst For Liquid Decarbonylation Of Furfural And Its Catalytic Properties

In the chemical production process, furan is a very important chemical raw material. Due to its excellent reactivity and the solubility, it can be used in many drug production, organic synthesis, and resin production process. In China, the scope of application of furan is increasing year by year. The traditional prepared methods of furan are as follows: decarboxylation of furoic acid, oxidation of furfural, oxidation of butadiene, decarbonylation of furfural. The method of decarbonylation of furfural becomes the focus of the study because of the high catalytic activity, low energy consumption, high yield of furan.The method of decarbonylation of furfural can be divided into gas phase method and liquid phase method. The biggest disadvantage of liquid phase method is the weakness of stability of catalyst which is easy to inactivation; therefore, it is necessary and suitable for the demand for furan industry to find a catalyst of high activity and good stability.Pd/γ-Al2O3 catalyst for liquid decarbonylation of furfural was prepared by impregnation-precipitation method for the first time. Effect of impregnation concentration; the type of competitive adsorbent; the concentration of competitive adsorbent; the type of reducing agent; the amount of reducing agent; initial impregnation solution pH; pH value of impregnation solution after adding carrier; impregnation time on catalyst activities were investigated. The impregnation concentration is 0.005 g/mL; the competitive adsorbent is maleic acid; the concentration of maleic acid is 0.1 mol/l; the reducing agent is formaldehyde; The appropriate initial impregnation solution pH is 1; pH after adding carrier impregnation solution is 7; reduction pH is 8; impregnation time is 60 min. XRD studies showed that Pd was reduced to elementary valence state in the catalysts. Estimated by Debye-Scherrer formula, the size of palladium particles in catalyst is 15 nm, TEM studies showed Pd particles are well dispersed, the average size of Pd particles is 15 nm. Results of SEM showed that the surface of catalyst distribute uniformly.Pd/γ-Al2O3 catalyst was utilized to decarbonylation of furfural. Effects of the amount of catalyst, reaction time were also investigated. Results showed that the best process condition is as follows:the amount of catalyst is 1%of furfural quality, reaction time is 6 h. The yield of furan is 92.2%. The life of catalyst is 80 h. The catalyst prepared by this method is more active than those prepared by conventional methods in liquid decarbonylation of furfural reaction.Further the causes of deactivation of catalyst were analyzed; results of ED AX showed that there is carbon element in deactivated catalyst, so the deactivation of catalyst can be attributed to carbon deposition.