Se doped boron carbonitride nanotubes as a metal-free catalyst for selective oxidation of lignin-derived vanillyl alcohol to vanillin with molecular oxygen

Selective oxidation of lignin-derived vanillyl alcohol to vanillin is a vital reaction due to the widely application of vanillin. From aspect of green catalysis and sustainability, metal-free based heterogeneous catalyst for the entitled reaction is promising. In the present work, Se doped boron carbonitride (Se-BCN) nanotubes catalyst was rationally prepared and employed as the metal-free catalyst for the entitled reaction. The conversion can achieve 94.4 % with the selectivity of 89.4 % at 120 °C for 4 h, which is higher than most reported metal-based catalytic system. The reasons for the enhanced activity and selectivity of Se doped BCN nanotubes catalyst were revealed from the kinetic investigation and adsorption of vanillyl alcohol and vanillin. Mechanism study reveals that radicals are involved in the entitled reaction.