Preparation Of Co-based Metal Oxide And Its Application In Liquid Phase Oxidation Of Benzyl Alcohol

Oxygen or air is used as an oxidant to prepare benzaldehyde through selective oxidation of benzyl alcohol,which meets the requirements of environmental protection and has important scientific significance and industrial value.The research work of this paper is centered on the liquid phase oxidation reaction of benzyl alcohol,mainly including the following two aspects:（1）The cobalt-containing composite metal oxide was prepared by XRD,low-temperature nitrogen adsorption and desorption,SEM,XPS and H₂-TPR methods to characterize the crystal phase structure,specific surface area and pore structure,surface morphology,near-surface chemical composition and valence state distribution of the catalyst;（2）Using the different metal oxides prepared above as catalysts and air as the oxidant,carry out the liquid phase oxidation reaction of benzyl alcohol,study the catalytic reaction performance of different metal oxide catalysts,and explore reactive species.The main conclusions obtained are:Ni-Co composite oxides were prepared by co-precipitation method and hydrothermal method,respectively,with similar crystal structure,but the reaction performance of Ni-Co composite oxide prepared by hydrothermal method was superior.A series of Ni-Co composite oxides with different Ni/Co ratios and a single Ni OX and Co O_xwere prepared by hydrothermal method,and their reaction performance showed obvious differences.The reaction performance of the Ni-Co composite oxide is better than that of a single Ni Ox and Co O_x,indicating that the oxides of the two metal components have a synergistic effect.The NCO_HT-1 catalyst with a Ni/Co ratio of 1/3 has the best reaction performance,which may be related to its higher defect oxygen density.A series of Mn-Co composite oxides with different Mn/Co ratios prepared by hydrothermal method have better reaction performance for the oxidation of benzyl alcohol than single Mn O_xand Co O_x.When Mn/Co is 3/1,the reaction performance of Mn-Co composite oxide is the best.When the reaction temperature is 100 ^oC and the reaction time is 5 h,the conversion rate of benzyl alcohol can be reaches 92.17%,and the selectivity of benzaldehyde reaches 99%.Compared with Ni-Co oxide,Mn-Co oxide has higher reactivity and can achieve efficient conversion of benzyl alcohol under milder reaction conditions.Through the research work of this paper,a composite metal oxide catalyst with excellent performance has been successfully synthesized,which can use air as the oxidant in the reaction system to realize the efficient conversion of benzyl alcohol,and the catalyst is easily separated from the reaction system,Shows good reusable performance.