Preparation Of The Catalyst For The Hydrogenation Of Nitroaromatic Compounds And The Catalyst For The Hydrolysis Of Cellulose

With the high-speed development of the chemical industry, the demand for catalysts will be more and more, and also will be stricter and stricter. Therefore, developing a new type of catalyst with superior performance has become a focus topic for many researchers. According to the hydrogenation of nitroaromatic compounds and the hydrolysis of cellulose, we developed two new types of catalyst for their applications respectively. The preparation and performance of the catalysts were also studied.In this paper, coconut shell activated carbon (AC) was successfully functionalized with diaminocyclohexane groups. The functionalized AC was used as a carrier to complex metal ions for preparation of the supported Pd, Pd-B and Pd-Ni-B. Pd or its alloy particles were highly dispersed on the functionalized AC and have a narrow size distribution of2～5nm. Amorphous structure of Pd-B and Pd-Ni-B were confirmed by XRD. XPS results showed that some of the electrons were transferred from B to Pd, which makes Pd electron-enriched. H2-TPD tests indicated that desorption peaks of the amorphous alloys shifted to higher temperatures with respect to Pd/C, indicating that hydrogen was more strongly bonded to the amorphous alloys.Their catalytic performances were evaluated in hydrogenation of nitroaromatic compounds. In hydrogenation of p-chloronitrobenzene (p-CNB), the Pd-Ni-B nanoalloys on the functionalized AC displayed a TOF value of8316/h, and p-CNB conversion of98.6%with a p-chloroaniline (p-CAN) selectivity of94.6%. The highly active hydrogenation property of the Pd-Ni-B/C was further confirmed in reduction of a-nitronaphthalene. In addition to reduction of-NO2groups, partial aromatic rings were also hydrogenated over the Pd-Ni-B/C. The substrate conversion was99.6%together with a highest TOF value of88/h.In addition, mesoporous H-ZSM-5zeolites prepared by alkaline treatment were successfully synthesized. The structures and properties of mesoprous H-ZSM-5zeolites were characterized by XRD, FT-IR, N2adsorption and SEM. Subsequently, hydrolysis of cellulose in ionic liquid (IL) over mesoprous H-ZSM-5was systematically studied. The results showed that mesoporous H-ZSM-5obtained by the treatment for30min was found to be a potential catalyst with76.2%cellulose conversion and49.56%yield of total reducing sugar (TRS). For the parent H-ZSM-5,41.3%cellulose conversion with33.21%yield of TRS was obtained, indicating that mesopores played a main role in elevating the TRS yield due to the diffusional alleviation of cellulose macromolecules. Meanwhile, the effects of reaction time, temperature and catalyst dosage were also investigated to obtain optimal process conditions. By using XRD, element analysis and N2adsorption, the characterization of the mesoporous H-ZSM-5behavior in IL was studied. It was found that IL could enter the inner channel of mesoporous H-ZSM-5to promote the generation of H+from Bronsted acid sites, which facilitated hydrolysis. The catalyst also showed excellent thermal stability and reusability, therefore, it has abroad prospect in hydrolysis of biomass.