Ab initio chemical kinetics of (2-furyl)(hydroxy)methyl with O2

In this work, based on the ab initio method, the reaction mechanism of the low-temperature oxidation of 2- furfuryl alcohol (2FFOH) is studied. (2-furyl)(hydroxy)methyl (furylCHOH, labeled as R) and O2 were taken as the bimolecular reactants, and the energy diagram was determined by a high-level quantum chemical method (CCSD(T)/ CBS//M05-2X/jun-cc-pVTZ). The equilibrium geometry and vibrational frequencies of the reactants, intermediates, transition states, and products were determined by the M05-2X/jun- cc-pVTZ method. Then, the Rice-Ramsperger-Kassel-Marcus/Master equation method was used to calculate the temperature- and pressure-dependent rate coefficients. O2 addition to furylCHOH needs to overcome energy barriers of 2.35-7.26 kcal/mol to generate three kinds of peroxide radicals, 2-[(2-furyl)(hydroxy)methyl]dioxidanyl (RO2α), 2- {2-[(Z)-hydroxymethylidene]-2,3-dihydro-3-furyl}dioxidanyl (RO2γ) and 2- {5-[(Z)-hydroxymethylidene]-2,5- dihydro-2-furyl}dioxidanyl (RO2ε). The calculation results show that peroxide RO2£ is the main product when the reaction temperature does not exceed 800 K at 1 atm. Moreover, furfural (P21) and HO2 become dominant when temperature is above 800 K at 1 atm, which are formed via concerted HO2 elimination mechanism of three peroxides. The slow reaction rate of RO2α→INT1 via an intramolecular 1,5 H-shift indicates the trend of low oxidation reactivity of 2FFOH.