Abstract:

Selective hydrogenation on fixed bed generally needs that the catalysts has good mechanical strength,appropriate specific surface area and pore volume,high dispersion of active components,etc.In order to overcome the problem of insuffi-cient formability and strength of Pd/CNTs catalyst,self-produced CNTs were purified and then combined with alumina to form composite carrier（CNTs-Al₂O₃）.The characterization results showed that CNTs were mixed well with Al₂O₃ in composite carri-er,the original tubular structure of CNTs was retained and the ports of CNTs were open.Contrast experiments showed that cat-alysts using composite carrier with adding 5%~10% CNTs（calculate as mass fraction） were more active than that catalyst us-ing Al₂O₃ alone after supported palladium acetate.Compared with HCl and HAc,the carrier had lower loss rates of specific surface area and pore volume,the dispersion of active components on the surface of carrier was better when CA and EDTA used as acidic complexing solvents for Pd.The selectivity and yield of target product could be higher when the reaction tem-perature was 90~110 ℃ and the hydrogen pressure was 1.2~1.6 MPa under the preferred catalyst system.

Key words: carbon nanotubes, selective hydrogenation, complexing agent