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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. 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. [ABSTRACT FROM AUTHOR]

This work aims to demonstrate that cresol, an important high added value chemical in petrochemical industry, can be directionally produced using cellulose. This novel controllable transformation process was achieved by selective catalytic pyrolysis of cellulose and catalytic oxidation. The zinc oxide-doped strong acidic zeolite catalyst promoted the formation of toluene intermediate in the catalytic pyrolysis of cellulose. The CuCr2O4@MCM-41 catalyst exhibited high activity and good reusability in the catalytic oxidation process. The highest cresol selectivity of 87.5% with conversion of 83.0% was obtained using the CuCr2O4@MCM-41 catalyst and hydrogen peroxide as a green oxidant under the optimized reaction conditions (60 °C, 4 h). Based on the study of the model compounds and catalyst characterizations, the reaction pathways and possible reaction mechanism for the catalytic transformation of cellulose to bio-based cresol have been proposed. [ABSTRACT FROM AUTHOR]

_Efficient synthesis of bio-based chemicals from renewable lignocellulosic biomass is of great significance to promote the sustainable development of chemical industry. This work aims to demonstrate that terephthalic acid, a bulk high value chemical in petrochemical industry, can be synthesized using biomass. This novel controllable transformation process was started with the selective catalytic pyrolysis of sawdust biomass to form p-xylene intermediate. The high p-xylene yield of 23.4% was obtained using the Ga 2 O 3 /SiO 2 /HZSM-5 catalyst under the optimized reaction condition. Subsequently, the selective oxidation of the biomass-derived aromatic intermediates to terephthalic acid was realized with the metal oxide catalysts. The highest terephthalic acid yield of 72.8% with the terephthalic acid selectivity of 82.3% was achieved using the CoMn 2 O 4 @SiO 2 @Fe 3 O 4 catalyst. Based on the study of the catalytic conversion of the model compounds and the catalyst characterizations, the reaction pathways and possible reaction mechanism have been proposed. Selective synthesis of bio-based terephthalic acid, a bulk high value chemical, was achieved by the biomass catalytic pyrolysis to p-xylene intermediate over the Ga 2 O 3 /SiO 2 /HZSM-5 catalyst and thesubsequent catalytic oxidation over the magnetic catalyst of CoMn 2 O 4 @SiO 2 @Fe 3 O 4. [Display omitted] • Selective catalytic synthesis of bio-based terephthalic acid was developed. • Ga 2 O 3 /SiO 2 /HZSM-5 catalyst has good performance for forming p-xylene intermediate. • CoMn 2 O 4 @SiO 2 @Fe 3 O 4 catalyst shows superior performance in alkylarenes oxidation. • Terephthalic acid yield of 72.8% was achieved under optimized reaction condition. [ABSTRACT FROM AUTHOR]

• Selective synthesis approach of bio-based benzoic acid from xylan was developed. • 3wt%ZnO/HZSM-5 catalyst had good performance for forming toluene intermediate. • 10wt%Co 2 MnO 4 @MCM41 catalyst showed superior performance in benzoic acid synthesis. • High benzoic acid selectivity of 88.3 % with high conversion of 90.5 % was achieved. The efficient synthesis of bio-based chemicals using renewable carbon resources is of great significance to promote sustainable chemistry and develop green economy. This work aims to demonstrate that benzoic acid, an important high added value chemical in petrochemical industry, can be selectively synthesized using xylan (a typical model compound of hemicellulose). This novel controllable transformation process was achieved by selective catalytic pyrolysis of xylan and subsequent catalytic oxidation. The highest benzoic acid selectivity of 88.3 % with 90.5 % conversion was obtained using the 10wt%Co 2 MnO 4 @MCM-41 catalyst under the optimized reaction conditions (80 °C, 4 h). Based on the study of the model compounds and catalyst's characterizations, the reaction pathways for the catalytic transformation of xylan to bio-based benzoic acid were proposed. Selective catalytic synthesis of bio-based high value chemical of benzoic acid was achieved by the catalytic pyrolysis of xylan over the ZnO/HZSM-5 catalyst and the catalytic oxidation over the Co 2 MnO 4 @MCM-41 catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]