| In recent years,this kind of energy has been greatly destroyed and wasted,and the pollution of this kind of energy is more serious,because of the large and irrational use of fossil energy.Therefore,exploring and developing renewable green energy instead of traditional fossil energy is an inevitable choice for human beings.Biomass as an important green renewable energy has attracted more and more attention in recent years.Also,biomass is mainly converted from waste straw,cottonseed shell and other low cost substances,this advantage of low cost and wide source makes it transform into a biomass derivative and is possible to industrialize.However,the key to biomass conversion lies in the catalyst,and traditional powder material has drawbacks such as being difficult to recycle and have poor stability,which makes the search for or designing a reasonable catalyst become an important issue for current research.Structured catalyst has a high specific surface area,a high active site,and a high cycle availability compared to catalyst for powder material,and these advantages make them more and more useful in many fields,such as catalysis.According to relevant literature reports,previous film catalyst was designed to prevent structural damage and generally used for some simple catalytic oxidation reactions after calcination,which greatly limited the promotion of film catalyst.In this paper,LDH thin film is prepared firstly,then calcined and reduced to get simple metal-containing film catalyst,which is used in catalytic hydrogenation and other reaction studies.This,not only demonstrate excellent catalytic properties,but also broaden the application of film catalyst in the field of catalysis.(1)The AAO substrate was obtained by electrolysis in a certain concentration of sulfuric acid solution by anodic oxidation,and CuZnAl-LDH film with regularly arranged pore structures was obtained by in situ growth on the surface by the ammonium nitrate method.The different components and proportions of LDH films were reduced by calcination to obtain corresponding CuZnAl film catalysts for catalytically selective hydrogenation of furfural.Compared with the same proportion of powder catalyst and different proportion of film catalysts,Cu4Zn1Al film exhibited better catalytic performance:furfural conversion rate of 93.6%,furfuryl alcohol selectivity up to 100%.This high catalytic performance reflects the high dispersion of Cu particles and the synergy between Cu and Zn.The coexistence of Cu0 and Cu+ may make the catalyst more active.In summary,the use of such film catalyst not only broadens the type of catalytic reaction,but also provides a scientific basis for its industrialization.(2)CuCoAl-LDH films with different compositions were obtained by in-situ growth method.After calcination and reduction,CuCoAl film catalyst with good morphology was obtained and catalyzed oxidation of glycerol was studied.Moreover,by investigating the influence of catalysts on the different reduction temperatures,it was found that the CuCoAl film obtained by the reduction at 400℃ has good catalytic performance,especially,the selectivity to glyceric acid up to 43.5%and the selectivity to oxalic acid up to 38.1%.Using XPS characterization,it was further found that this temperature-reduced film catalyst has more Co2+ and oxygen deficiencies.The above shows that the film formed by the combination of cobalt oxide and reduced copper is more conducive to the oxidation of glycerol,and the reaction performance and morphology are not much changed after repeated times. |
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