关键词: 邻羟基甲苯, 邻羟基苯甲醛, 催化氧化, 基团贡献法, 热力学

Abstract: Catalytic oxidation of o-hydroxytoluene(ONT)is the main process to synthesize o-hydroxybenzaldehyde(OHBA),but the key problem is how to improve selectivity and yield of target product.In order to make more effective use of resources,the thermodynamic properties of o-hydroxytoluene oxidation were analyzed.The basic thermodynamic data of the reaction products were estimated through several group-contribution methods.According to the basic thermodynamic principles,the relationships between reaction temperature and reaction enthalpy change,reaction Gibbs free energy change,and reaction equilibrium constant were established.The calculation results were as follows:R₁:Δ_rH₂₉₈^Θ＝-158.36 kJ·mol^-1,Δ_rG₂₉₈^Θ＝-170.93 kJ·mol^-1; R₂:Δ_rH₂₉₈^Θ＝-214.53 kJ·mol^-1,Δ_rG₂₉₈^Θ＝-163.56 kJ·mol^-1; R₃,Δ_rH₂₉₈^Θ＝-259.35 kJ·mol^-1,Δ_rG₂₉₈^Θ＝-260.27 kJ·mol^-1.In the researched reaction temperature range,all the reaction steps were exothermic reactions and could proceed spontaneously,and a higher reaction temperature went against the reaction procedure.The thermodynamic analysis results provided the basic data for research on improving selectivity of target product,and could guide optimizing reaction conditions and commercialization.

Key words: o-hydroxytoluene, o-hydroxybenzaldehyde, catalytic oxidation;group-contribution method, thermodynamics