| With the dwindling of fossil fuels and the increase of greenhouse effect,green energy resource is more and more important.Beacuse of wide availability of raw materials,zero release of CO2 and feasible convertsion into liquid fuels,biomass becomes to be a first choice of alternative to fossil fuels.In consideration of its variety of components,instability of chemical property and a high oxygen content,before widely application,it must go through a deoxygenation upgrading process.Ni2P Supported catalysts have extensively been studied for various hydrodeoxygenation(HDO)reactions.However,main products are cyclohexane or cyclohexanol for lignin-derived compound HDO over catalysts reported.For HDO reactions,selective hydrogenation to aromatic compounds successfully to deoxygenation together with a lower consumption of H2.In this work,catalytic conversion of anisole,phenol and guaiacol to benzene over N2P/SiO2 by searching reaction conditions was investigated.Results show that lower reaction temperature and higher H2 pressure favors hydrogenation of these model chemicals to cyclohexane while higher reaction temperature and lower H2 pressure conduce to the generation of benzene.Cyclohexane and benzene yields are 89.8%and 96.0%at 1.5 MPa,573 K and 0.5 MPa,673 K respectively.By eliminating the influence of internal and external diffusion,the lower intrinsic activation energy,58.2 kJ/mol,is obtained to understand the high catalytic activity.In addition,although guaiacol HDO due to space steric effect of substituent has a low conversion,it presents similar reaction pathway dependent on reaction conditions to anisole and phenol.Long-run evaluation experiment shows that activity and selectivity of anisole HDO to benzene change slightly for 36 h.Moreover,in consideration of their own advantages of N2P and Pd catalysts respectively,the bifunctional catalyst Pd-N2P catalyst showed a more excellent deoxidation rate at a low temperature compared with the single catalyst. |
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