Biochar-based solid-acid catalysts for the selective oxidation of glucose to α,β-unsaturated carboxylic acids in water

H2SO4-modified biochar loaded with TiO2 nanoparticles (SBC) was synthesized via anoxic pyrolysis of rice straw biomass. This SBC material was employed for the photo-Fenton-like oxidative conversion of D(+)-glucose into α,β-unsaturated carboxylic acids (UCAs). Varying catalyst and peroxide loadings generated multiple reactive oxygen species (ROS), including •OH and •O2–, as well as photogenerated electrons and holes. Remarkably, a 90.8 % glucose conversion rate was achieved within 4 h, with an overall carboxylic acid production rate of 463.0μ mol.gcat-1.h-1 and 330.3μ mol.gcat-1.h-1 for UCAs, while maintaining a high selectivity of 71 %. This study elucidated the mechanism through UHPLC-MS/MS analysis, demonstrating the potential of SBC for sustainable glucose valorization and renewable chemicals production.