Abstract:

Catalytic conversion of biomass to bulk chemicals is in line with the important research strategy of low-carbon， transferring cellulose derivative ethyl levulinate to 1，4-pentanediol is one of the most promising technological routes. The non-precious metal copper-based catalysts show good activity in this reaction， and the yield of 1，4-pentanediol from ethyl levulinate hydrogenolysis is only 50.8% on the Cu/Al₂O₃ catalyst at 160 ℃ with 4 MPa H₂. The catalytic performances are significantly improved after being modified with rare earth element， and the yield of 1，4-pentanediol reaches 92.7% on the CuNd_0.25/Al₂O₃ catalyst. Based on the catalytic performances and the characterizing results of X-ray diffraction（XRD），transmission electron microscope（TEM）， hydrogen temperature programmed reduction（H₂-TPR）， ammonia temperature programmed desorption（NH₃-TPD）and diffuse reflectance infrared Fourier transform（CO-DRIFT）， the presence of rare earth elements not only changes the reduction properties， dispersion， and electronic structure of Cu species， but also alters the distribution of acidic and basic sites on the catalyst surface. The doping of rare earth element could promote both the adsorption and activation of reactants on the catalyst surface and inhibit the side reaction of the target product 1，4-pentanedioldehydration， thus improving the activity and selectivity.

Key words: Cu/Al₂O₃, Rare earth doping, 1, 4-Pentanediol, Ethyl levulinate, Hydrogenolysis