Preparation And Properties Of Palladium On Carbon Catalyst Supported On Different Carbon Supports

In the present study, a series of carbon materials were prepared. Several Pd(OH)2/C catalysts for the hydrogenolytic debenzylation of Hexabenzylhexaazaisowurtzitane(HBIW) were pepared through deposition-precitipitation method with several types of carbon materials as carriers.(1) A series of carbon materials were preparedGraphene oxide(GO) was prepared: GO was prepared from pristine graphite by Hummers' method, the GO presented a wrinkled and rippled sheet-like structure.Mesoporous carbon materials(MC and CMK-3) were prepared: The hard template method of CMK-3 and MC. CMK-3 is the ordered mesoporous structures and MC is the disordered mesoporous structures. MC have a several of porous structures: 3 – 4 nm, 5 – 6 nm, 6 – 7 nm, 10 – 11 nm.Activation of carbon: XC-72(Cabot Company) and cocoanut active carbon(denoted as AC, Yida Filter Material Limited Company) were purchased. They were activation by adopting the method of chemical activation.(2) Catalysts for the hydrogenolytic debenzylationDifferent carbon(GO, CNT, XC-72, AC, CMK-3 and MC) supported Pd catalysts were prepared by the method of precipitation. The sample was obtained and denoted as Pd(OH)2/GO, Pd(OH)2/CNT, Pd(OH)2/XC-72, Pd(OH)2/AC, Pd(OH)2/CMK-3 and Pd(OH)2/MC, where the loading of Pd was 10 wt. % for each catalyst.(3) Catalysts for the hydrogenolytic debenzylationThe catalytic hydrogenation debenzylation of HBIW was carried out in the same condition. Among the carbons studied, the disordered mesoporous carbon as a support exhibited high yield of 80 % in HBIW hydrogenation reactions, which was even better than that of commercial catalysts which was one of the best catalysts as reported, the commercial E101 NE/W exhibited a high yield of 78 %.(4) Catalysts for the recycle performance testCommercial E101 NE/W and MC supported Pd catalysts were tested for hydrogenation debenzylation of HBIW by reusing the catalysts. The used catalyst was collected and reused for later reaction run. Under the same condition of same cycle test. After the second runs, the yield of E101 NE/W catalyst was considerably low 13 %. The yield of Pd/MC catalyst remained high more than 70 % for three runs. According to hydrogenation debenzylation result, the MC was assumed to be a more suitable support for Pd catalysts used for HBIW hydrogenation debenzylation.