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:ΔrH298Θ＝-158.36 kJ·mol-1

ΔrG298Θ＝-170.93 kJ·mol-1; R2:ΔrH298Θ＝-214.53 kJ·mol-1

ΔrG298Θ＝-163.56 kJ·mol-1; R3

ΔrH298Θ＝-259.35 kJ·mol-1

ΔrG298Θ＝-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.