Synthesis of Heterogeneous Nanocomposite Catalyst ZrO₂@SBA-15 for Formic Acid Production from Hemicelluloses

Heterogeneous nanocomposite ZrO₂@SBA-15 catalysts containing 10 wt % of zirconium oxide were synthesized by two methods: (i) co-condensation and (ii) incipient wetness impregnation. The catalysts and their carriers were characterized by X-ray powder diffraction, X-ray fluorescence analysis, low-temperature nitrogen adsorption–desorption, and FTIR-spectroscopy. As a result of zirconia introduction into the silica wall, the mesostructure of SBA-15 is preserved, but the specific surface area and pore volume are reduced. It was found that during one-stage synthesis, the particle fibers shorten and stick together. The catalysts were tested in the process of catalytic hydrolysis-oxidation of hemicelluloses of aspen wood. The optimal formic acid synthesis conditions were determined to be 150°С and 3 h. The highest formic acid yield obtained using the catalyst prepared by co-condensation under best reaction conditions was 28.4 wt %.