Hydrogenation Of Phenol By Using A Noble-metal-free Ni-Ag/SBA-15 Bimetal Catalyst In High-temperature Water System

Due to the continuous consumption of fossil fuels,conversion of biomass into biofuels(i.e.,an alternative)has been attracted much attention.By pyrolysis and liquefaction treatment,the biofuels,which include phenolic oils,furans and other organic acids,etc.,can be obtained from biomass.Although own higher energy density,the other properties(e.g.,low calorific value and poor chemical thermal stability)of the biofuels limit them to be directly used for driving some commercial engineers.Therefore,enhancement of the thermal-stable and calorific value of biofuels is necessary for achieving their industrail application.As a main biofuel,phenolic oil is more resistant to hydrogenation.The products after hydrogenation are mostly alcohols,and its calorific value is higher than other biofuels.Therefore,it is more practical to study the catalytic hydrogenation of phenolic oil for oil upgrading.In this study,phenol was selected as a model compound.Based on the research of the research group of kunming university of science and technology,the catalytic hydrogenation reaction of the mold compound in high-temperature water system(HTW)was studied.To explore the low-cost noble-metal-free phenol hydrogenation catalyst,a cost-effective Ni-Ag/SBA-15(15 wt%)catalyst was prepared by coprecipitation method and further characterized by BET surface area,XRD,XPS,and TEM-EDS.The lifetime of Ni-Ag/SBA-15 catalyst was evaluated.The results showed that the catalyst could be reused.Hydrogenation process of phenol has been also carried out in a high-temperature water(HTW)system.The results showed that compared with Ni/ sba-15 catalyst,Ag/ sba-15 catalyst and no catalyst,ni-ag/sba-15 bimetallic catalyst could effectively improve the conversion rate of phenol and the selectivity of cyclohexanol in HTW.The conversion rate of phenol increased with the increase of reaction time and temperature,especially at 260℃,the conversion rate reached 79%,and the yield and selectivity of cyclohexanol reached 75%.A kinetic modeling has been also proposed,from which can be known that the activation energy(Ea)of generation of cyclohexanone was 55.3479 kJ/moL and cyclohexanol was 122 kJ/moL,respectively.Therefore,the non-noble bimetallic catalyst Ni-Ag/SBA-15 obtained in this study has the characteristics of low cost.It shows great potential for the catalytic hydrogenation of phenol to cyclohexanol under HTW system,and provides a new research idea for the industrialization of bimetallic catalytic hydrogenation with high activity and low cost.