Aerobic epoxidation of α-pinene using Mn/SAPO-34 catalyst: Optimization via Response Surface Methodology (RSM)

Abstract

Aerobic epoxidation of bio-based olefins is an important topic in green and sustainable chemistry. In this work, an Mn/SAPO-34 catalyst was prepared by ion-exchange method for the epoxidation of α-pinene in presence of molecular oxygen and iso-butyraldehyde. The factors influencing α-pinene epoxidation were determined and the conditions were optimized by response surface methodology (RSM). The result showed that the sensitive conditions were co-reductant amount, Mn loading amount and catalyst amount. After optimization, α-pinene was completely converted and a 90.47% yield of 2,3-epoxy-pinane was obtained. The result showed that the catalyst was reusable for six cycles. In addition, the support and catalysts were characterized by XRD, BET, ICP-OES, SEM-EDS, TEM and XPS, and it was confirmed the reasons for the degradation of the catalyst activity were the damage of crystal particles, the decrease in specific surface area of catalyst, the loss of active components and the irreversible oxidation of Mn2+