Preparation And Hydrogenation Properties Of Nano-metal Catalysts Loaded With Biomass Carbon-based Materials

Both furfural and levulinic acid are important biomass platform compounds,and a variety of high value-added chemicals and fuels can be prepared by hydrogenation reaction.Efficient and stable catalysts are extremely important for the hydrogenation of these two compounds.At present,the research on catalysts is mainly about multi-metal catalysts and the carriers are almost metal oxides.There are few studies on carbon-based non-precious metal catalysts.Using biomass as a raw material,functional carbon materials can be prepared and applied to adsorption,electrode materials,catalyst carriers,and so on.Owing to the excellent properties of carbon material,it is suitable for the application of catalyst carrier.Based on it,we developed a simple and green method to prepare carbon material supported metal catalyst by using pomelo peel as raw material.Meanwhile,we explored the catalyst formation mechanism and researched the hydrogenation ability through the hydrogenation of furfural and levulinic acid.To prepare biomass-based carbon material supported metal catalyst,pomelo peel was used as carbon source and nitrate was used as metal source.The in-situ carbonization reduction preparation method is simple and green.Fe/C,Co/C,Ni/C and Cu/C catalysts were prepared through this method.The particle size of Ni/C and Cu/C catalysts were 4.2nm and 8.6nm,respectively.By a series of characterizations,it was found that we can obtain reduced metal loaded on catalyst without additional reduction.Based on the characterization results and the related references,the possible catalyst formation mechanism was given in this paper.It can provide reference for the preparation of biomass carbon-based metal catalysts.In general,Cu-based catalysts own high selectivity of furfuryl alcohol for the hydrogenation of furfural.Therefore,Cu/C catalyst was used for the hydrogenation of furfural to test its hydrogenation performance.The concentration of furfural,reaction temperature,reaction time,metal loading and catalyst calcination temperature were investigated.Among these factors,the calcination temperature affected the particle size and dispersion of Cu a lot,thus resulting the difference in catalytic performance.Cu/C catalyst exhibited excellent catalytic performance by optimizing experimental.With the calcination temperature of 400?,the reaction temperature of 170?,the H₂pressure of 2 MPa,and the reaction time of 3 h,the conversion of furfural and the selectivity of furfuryl alcohol were 99.6%and 99.3%,respectively.The selectivity of furfuryl alcohol was extremely high when using Cu/C catalyst,which can remain 97.3%even though the reaction temperature was raised to 240?.The Cu/C catalyst also showed excellent cycle performance,and the conversion of furfural was 90.3%after10 cycles,which means no significant deactivation of Cu/C catalyst.To test the hydrogenation performance of the Ni/C catalyst,it was applied to the hydrogenation of levulinic acid.In order to compare the catalytic performance,Ni/AC and Ni/DC catalysts were prepared by carbothermal reduction method.These three catalysts were different in phase composition of metal and surface morphology,thus leading to different catalytic performance in the hydrogenation of levulinic acid.The effect of different reaction factors on the hydrogenation performance of levulinic acid was investigated.With the reaction temperature of 160?,the reaction time of 3 h,and the hydrogen pressure of 4 MPa,the conversion of levulinic acid and the yield of?-valerolactone was 100%and 94.2%,respectively.The catalyst deactivation was obvious after six cycles.The analysis showed that the reason of the deactivation was mainly the oxidation and leaching of the metal Ni.