Liqiu Mao

Microwave-assisted hydrolysis of crystalline cellulose catalyzed by biomass char sulfonic acids

The development of an environmentally benign process for the hydrolysis of cellulose into reducing sugars can be one of the key technologies for making full use of cellulosic biomass in the future. Here, a biomass char sulfonic acid (BC-SO3H)-catalyzed hydrolysis of cellulose in water was achieved under microwave irradiation. The BC-SO3H catalysts prepared cheaply from natural bamboo, cotton and starch, showed a much higher turnover number (TON, 1.33-1.73) for this reaction compared to a dilute H2SO4 solution (TON, 0.02), which was likely due to their strong affinity to β-1,4-glycosidic bonds of cellulose. In addition, microwave irradiation played key roles in activating cellulose molecules and strengthening particle collision, which can lead to a remarkable acceleration effect on this heterogeneously catalytic process.

A non-nitric acid method of adipic acid synthesis: organic solvent- and promoter-free oxidation of cyclohexanone with oxygen over hollow-structured Mn/TS-1 catalysts

A novel hollow-structured Mn/TS-1 catalyst has been reported as a non-nitric acid route for adipic acid production from oxidative cleavage of cyclohexanone. The method generates adipic acid in high yields with molecular oxygen under organic solvent- and promoter-free conditions. The hollow nature of the catalyst with large intra-particle voids facilitates the diffusion of bulky molecules to the internal catalytic site and increases the catalyst activity. The advantage of this catalyst is its reusability with almost consistent reactivity, thereby making it viable for industrial applications.

A novel route for preparation of Mn-containing hollow framework TS-1, and its selective allylic oxidation of cyclohexene

A new manganese-containing hollow framework TS-1 (MTS-1) was prepared via simple recrystallization of traditional TS-1 in the presence of tetrapropylammonium hydroxide (TPAOH) and manganese(III)–acetylacetonate, and its catalytic performance was tested for aerobic oxidation of cyclohexene without any solvents. This hollow bimetal TS-1 catalyst is more active than catalysts containing Mn or Ti solely; the formation of metal framework sites may be responsible for increased activity. The characterization techniques such as UV-vis, FT-IR, Raman, XRD, N2-adsorption, TEM, and XPS confirm the incorporation of Mn and Ti in the zeolite framework sites. This hollow catalyst shows high catalytic activity and stability (ten cycles) in the oxidation of cyclohexene, and demonstrates the potential of TS-1 catalysts for use in aerobic oxidations.