The development of efficient synthetic pathways for bio-chemicals is beneficial to sustainable development of chemical industry. The purpose of this work is to prove that p-tolylaldehyde, an important chemical, can be selectively produced from lignocellulose. This novel transformation has been achieved by the catalytic pyrolysis of lignocellulose to p-xylene intermediate over the magnetic zeolite catalyst of Fe₃O₄@SiO₂@HZSM-5 and the selective catalytic oxidation of the aromatic intermediate to p-tolylaldehyde over the magnetic catalyst of Cr(OH)₃@Fe₃O₄-V. The screening and characterization of catalysts, the reaction condition optimization as well as the catalyst’s reusability were studied. The highest p-tolylaldehyde yield of 51.0% was achieved using the Cr(OH)₃@Fe₃O₄-V catalyst. According to the catalyst characterizations and the analysis of the reaction intermediates, the reaction pathways were proposed.

Graphical abstract

Directional synthesis of bio-based p-tolylaldehyde, a bulk high value chemical, was achieved by coupling catalytic pyrolysis of lignocellulose biomass to p-xylene intermediate over the magnetic zeolite catalyst of Fe₃O₄@SiO₂@HZSM5 and the catalytic oxidation of aromatic intermediate over the magnetic Cr(OH)₃@Fe₃O₄ catalyst.