生物还原制备Au/γ-Al_2O_3催化葡萄糖氧化动力学研究

Kinetics of D-glucose Oxidation to D-gluconic Acid with Hydrogen Peroxide over Bio-reduced Au/γ-Al_2O_3 Catalysts

主要讨论了生物还原制备Au/γ-Al2O3催化剂用于催化葡萄糖氧化动力学的研究.利用甲烷氧化菌素(Methanobactin,Mb)作为还原剂及稳定剂制备了1%Au/γ-Al2O3催化剂.通过TEM分析,负载纳米金颗粒(Gold nanoparticles,AuNPs)粒径为3.48±0.881 nm.比较Mb及Au/γ-Al2O3催化剂的FTIR发现,在Au/γ-Al2O3催化剂表面整合有Mb基团.实验建立了幂指数速率模型,确定了D-葡萄糖、H2O2、催化剂、葡萄糖酸钠的反应级数,分别为:0.4696、0.3729、0.4088和-0.9794.同时通过阿伦尼乌斯曲线求得该催化剂活化能(Activation energy,Ea)为6.114 kJ/mol.最后通过验证该速率模型发现,预测值与实验值具有良好的拟合性.

In this paper,the kinetics of oxidation of D-glucose with H2O2 over heterogeneous bio-reduced Au /γ-Al2O3 catalysts had been mainly discussed.A catalyst with 1% Au support on alumina was prepared by using Mb which played dual roles as both reductant and stabilizer.The average Gold nanoparticles(AuNPs) size was calculated to be around 3.48 ± 0.881 nm by TEM images.In addition,comparing the FTIR spectrum of Mb and Au /γ-Al2O3 catalysts indicated the involvement of biomass groups in the synthesis.By fitting the kinetic data using power-rate law model after eliminating mass transfer resistances,the orders of the reaction of D-glucose,H2O2,catalyst and sodium gluconate were found to be 0.4696,0.3729,0.4088 and-0.9794,respectively.The activation energy(Ea) was calculated to be 6.1141kJ/mol from an Arrhenius plot.Based on the kinetic rate equation,the model predictions were in good agreement with the experimental data.