The DICP research team headed by Prof. ZHANG Tao and in collaboration with Prof. Jingguang Chen of the Delaware University, USA, has accomplished a research paper entitled "Direct Catalytic Conversion of Cellulose into Ethylene Glycol Using Nickel-Promoted Tungsten Carbide Catalysts", which has been published as a cover-paper in the Angew. Chem. Int. Ed. recently (Angew. Chem. Int. Ed. 2008, 47, 8510 - 8513).
Cellulose is one of the most abundant bio-mass resources in nature, and due to its non-edible characteristics, large scale utilization of this material as energy or chemical resources will not give rise to a negative effect on world-wide foodstuff supply. Accordingly, cellulose is regarded as a promising source for manufacturing sustainable energy supply and organic chemicals. However, cellulose is also one of the most difficultly hydrolyzed substances, which is generally treated conventionally first with liquid acids, alkalis or enzymes to convert it into glucose, then further transform the glucose into some forms of energy or chemicals. These traditional processes are usually tedious and polluting. In recent years, researchers have tried to convert cellulose in the presence of noble-metal catalysts into hexa-basic alcohols, and this is regarded as a green approach. However, the rather low selectivity of the process as well as the high cost of the noble-metal catalysts has hindered commercial application of this approach.
In the DICP work, by considering the noble-metal-like properties of tungsten carbides, the investigators tried for the first time to use low-cost tungsten carbide catalysts for the conversion of cellulose into polybasic alcohols. They found that tungsten carbide, when supported on an activated carbon carrier, not only could transform cellulose into polyols, but also exhibited an extra high selectivity to glycol. Especially, when small amount of nickel was added as a promoter, the selectivity to glycol could be as high as 61%. Glycol, usually manufactured from petroleum feedstuffs, is a widely used raw material, and is increasing
in the rate of 5% per year. These results of the DICP investigation might open up a new route for producing glycol from bio-masses instead of petroleum resources, thus attracting the attentions of the glycol-manufacturing companies as well as the news media.