Catalytic Conversion of 2-Phenethyl Phenyl Ether and 2-Phenoxy-1-Phenyl Ethanol Over ZSM-5, Y and Beta Zeolites

Catalytic conversion of 2-phenoxy-1-phenyl ethanol (PPE-OH) and 2-phenethyl phenyl ether (PPE) was conducted in an autoclave reactor using Faujasite zeolite (HY), Beta zeolite (HBEA), and Zeolite Socony Mobil-5 (HZSM-5) with medium and large pore channels. All catalysts were thoroughly analyzed using various techniques like FT-IR, N₂ physisorption, XRD, SEM-EDX, NH₃-TPD, ICP spectroscopy, and thermogravimetric analysis (TGA). The results showed that HBEA and HY catalysts, with their larger pore channels and sizes, exhibited excellent activity in breaking the ether bond of PPE-OH. HBEA and HY zeolites exhibited almost full conversion of PPE-OH at 240 °C and 1 h, and HZSM-5 zeolite obtained only 47% conversion of PPE-OH at the same condition. The cleavage of the ether bond of β-O-4 linkage was performed over HBEA and HY zeolites better than HZSM-5 zeolite. Moreover, high-strong acid sites of HBEA zeolite favored breaking PPE at 240 °C and 1 h, and PPE did not convert over HY and HZSM-5 zeolites at the same condition. These findings highlight the crucial role of pore size and channels and the acidity of catalysts for converting large molecules like lignin. This study provides valuable insights into using zeolite catalysts for breaking down the β-O-4 linkage in lignin.