Preparation Of P-WO₃ Supported Catalysts And Their Activity In The Conversion Of Furfuryl Alcohol To ?-angelica Lactone

Due to the continuous increase in resource consumption,the depletion of nonrenewable resource and increasingly serious pollution problems,the conversion of green and environment-friendly biomass source into high-value products and biofuels has attracted much attention.After pyrolysis or depolymerization of biomass,a series of liquid compounds can be generated,and further conversion can produce clean fuel oil and fine chemicals with high added value.Furfuryl alcohol,as an important platform compound derived from the hemicellulose in agricultural and forestry wastes,can further produce various fine chemicals,which was widely studied.In this paper,we took the conversion of furfuryl alcohol into?-angelica lactone as a target reaction,focusing on the preparation of catalyst and the regulation of catalytic performance.A variety of characterization methods such as XRD,BET,FT-IR,XPS,NH3-TPD,Py-IR,TGA,Raman were used to study and analyze the morphology and structure of the catalyst.The effects of elemental composition,calcination temperature,catalytic reaction temperature and pressure on the conversion and product selectivity were studied in detail.Firstly,using WO₃ as the active component and activated carbon as the support,WO₃/AC catalysts were prepared.During the conversion of furfuryl alcohol into?-angelica lactone,with the increase of WO₃ content,the yield of?-angelica lactone was increased firstly and then decreased and the highest yield was 82.0%.In order to improve the catalytic activity,further research on P modification of this catalyst was carried out.After modified by P element,the activity was improved.When the W/P molar ratio was adjusted to 2 and the calcination temperature was 500°C,the prepared P-WO₃/AC catalyst showed the highest activity:the conversion of furfuryl alcohol and the yield of?-angelica lactone reached up to 97.1%and 91.6%after reaction at 160°C and 3 MPa hydrogen pressure for 2 h,respectively.The high activity was attributed to the large specific surface area,the good dispersion of active component and the synergy between P and W.The reusability study showed that the stability of the catalyst was not good.In the second run reaction,the conversion of furfuryl alcohol and the yield of?-angelica lactone decreased to 33.8%and 30%,respectively.In comparison with the characterization results of the catalyst before and after the reaction,the carbon deposition on the catalyst surface is the main reason for the catalyst deactivation.When the spent catalyst was regenerated via a simple calcination procedure,the catalytic activity was recovered to a certain extent,and the yield of?-angelica lactone raised to 77.5%.Secondly,a serial of P-WO₃/SiO₂ supported catalysts were prepared via using ammonium metatungstate,diammonium hydrogen phosphate as tungsten and phosphorus sources.After optimizing the reaction conditions,when the W/P molar ratio and the calcination temperature were adjusted to 2 and 700°C,respectively,the prepared P-WO₃/SiO₂ catalyst showed excellent activity in the conversion of furfuryl alcohol into?-angelica lactone:the conversion of furfuryl alcohol and the yield of?-angelica lactone reached up to 97.3%and 75.9%after reaction at 80°C and 3 MPa hydrogen pressure for 2 h,respectively.However,the catalyst deactivation was also observed,but which could be recovered after a simple calcination at 400°C.Therefore,this catalyst still presents good potential application...