Research On The Selective Transformation Of Molecular Alcohols With Iron Nanomaterials

In recent years,the synthesis of carbonyl compounds from the transformation of different alcohols catalyzed by metal nanomaterials has gradually become a hot topic in the catalysis field.In this thesis,the influence factors in the selective oxidation of aromatic alcohol and the acetylation of glycerol promoted by Fe-based catalysts have been detailedly studied,and the efficient synthesis of aromatic aldehydes and triacetin from molecular alcohols is achieved.The catalysis of iron nanomaterials contains numerous merits which are high activity,easy separation and recycling use.Therefore,the research is of significance on science and industrial application.First,the selective oxidation of aromatic alcohols using metal nanoparticles loaded iron doped grapheme as catalysts was investigated.The iron doped graphene was prepared with glucose and ferric chloride as the reactants,and then the depositon precipitation method was used to load the metal nanoparticles on the support to prepare the Au/Fe-Gr,Pd/Fe-Gr,Au-Pd/Fe-Gr and Pt/Fe-Gr catalysts.These metallic catalysts were respetively characterized by infrared（IR）,thermogravimetric（TG）,X-ray diffraction（XRD）,physical adsorption（BET）,chemical adsorption（TPD）and other techniques.Moreover,the above nanomaterials were further used in the selective oxidation of benzyl alcohol.As a result,it was found that the Au/Fe-Gr or Au-Pd/Fe-Gr catalyst showed a good catalytic performance in the oxidation of benzyl alcohol.For example,when the Au/Fe-Gr material was employed as the catalyst,in the presence of additive potassium carbonate,the conversion of benzyl alcohol and the selectivity of methyl benzoate was 96.2 % and 99.9 % in methanol solvent during 8h,respectively,Otherwise,in n-butanol solvent,the conversion of benzyl alcohol and the selectivity of benzaldehyde is 89.1 % and 87.5 % in the presence of the Au-Pd/Fe-Gr catalyst during 6 h,respectively.These two catalytic systems were also used in the selective oxidation of other aromatic alcohols where methoxybenzyl alcohol and cinnamyl alcohol are effitively oxidized to the corresponding aldehyde molecules under the mild conditions.Then,a possible reaction mechanism was proposed according to experimental phenomena and catalytic valuation.On the other hand,the acetylation of glycerol catalyze by the iron containing solid acid catalyst was also studied.A series of Fe-Sn-Ti(SO₄^2-)-T catalysts were prepared and further used in the reaction of glycerol with acetic anhydride.From the catalytic experimental results,it could found that the Fe-Sn-Ti(SO₄^2-)-400 catalyst showed better performance than other acid catalysts;then,the effect of reaction temperature,time,and catalyst recycle on the glycerol acetylation were tested,and the optimized reaction conditions are found to be reaction temperature of 80 °C,reaction time of 30 min.As a result,the conversion of glycerol could reach up to 100 % and the selectivity of main product triacetin was 99 %.In addition,the physical properties of solid acid catalysts were characterized by IR,X-ray diffraction,physical adsorption and TG and other techniques.At last,the catalytic reaction mechanism is concluded from the characterization data and experimental results.