Dehydroxylation of biomass-based platform molecules is critical for obtaining building blocks for use in the chemical industry. Acid catalytic dehydration has provided a feasible route. However, simultaneously pursuing high product-selective and ultra-stable catalysts for the dehydroxylation of polyols remains an open challenge. In this study, a strategy for in-situ Bronsted acid sites (BAS) with chemo-adsorption selectivity is proposed. The construction of defect sites B[3] and P[4] species has been proved to be a prerequisite for the dynamic acid site formation at hydrothermal conditions. The BPO4 catalyst with in-situ BAS can achieve the high selectivity of acrolein (similar to 80%) and robust stability of catalyst (over 425 h) using glycerol dehydration as a model reaction. In addition, in-situ BAS is highly selective for secondary hydroxyl groups and has been extended to other substrate applications. This catalytic strategy provides a green, efficient, and economical approach for converting biomassderived polyols to high-value-added chemicals.

The mild alkali-treated 13X was employed in the liquid phase isomerization reaction of α-pinene to increase the yield of limonene. A maximum α-pinene conversion of 100% and limonene yield of 59.1% could be achieved. Crystallinity could be well retained, and the amounts of medium-strong acid sites and the distribution of Brønsted and Lewis acid sites could be changed after the mild alkali treatment for 13X zeolite. Samples with higher micropore specific surface area were easier to obtain higher yields of limonene due to shape-selectivity. A proper amount of the medium-strong acid and the synergistic effect of Brønsted and Lewis acid sites were beneficial to enhance the catalytic activity and the yield of monocyclic product limonene. The main reason for catalyst deactivation could be the decrease in the active sites due to soft coke deposition. For the regeneration process, the conversions of α-pinene were between 95% and 99% during the first seven cycles and the conversion dropped to 90.6% after the eighth cycle, which demonstrated that the ethanol flushing and calcination could be an effective regeneration method for the 13X catalyst used in the α-pinene isomerization reaction.

Sustainable synthesis of acrolein, a key chemical intermediate, from biomass-derived glycerol is highly attractive. However, conventional catalysts for the dehydration of glycerol suffer from low acrolein selectivity and high deactivation tendency. Herein, a novel green catalyst (HPW/T0.6 S-COOH) was prepared and employed in the dehydration of glycerol in a continuous flow reactor. The performance of different catalysts and the effects of reaction conditions (reaction temperature, N2 flow rate, and glycerol concentration) were examined. The HPW/T0.6 S-COOH catalyst provides the best glycerol conversion of 96.38% and acrolein selectivity of 92.01%. The NH3-TPD and pyridine-FTIR results indicate that the Brønsted acid site is more susceptible to acrolein, while the weak strength acid site effectively prevents the further reaction of acrolein, providing practical insights for the rational design of efficient and continuous synthesis of acrolein catalysts. A novel green catalyst HPW/T0.6 S-COOH was synthesized for the dehydration of glycerol. The dehydration in a micro bed packed with the novel catalyst achieves high glycerol conversion and acrolein selectivity of 96.38% and 92.01%, respectively. Weak Brønsted acid site is proved to contribute to the high selectivity to acrolein.