Preparation of Cyclodextrin-Based Carbonaceous Catalyst and Its Application in the Esterification

A new carbonaceous catalyst with sulfonic acid group （-SO3H） was prepared by incomplete carbonization of β-cyclodextrin followed by sulfonation.The sulfonated amorphous carbon was characterized by IR,elemental analysis,DSC-TGA and PXRD,and the catalytic activity was investigated to be an efficient catalyst for the esterification reactions with maximum yield of 87%.The sulfonated carbonaceous catalyst was readily separated from the reaction solution and keeps approximately equal catalytic activity.The results confirm that the active centre is the hydrophilic sulfonic acid functional group in the esterification reactions.

Imidazolium ionic liquid-supported sulfonic acids:Efficient and recyclable catalysts for esterification of benzoic acid

Several imidazolium ionic liquid（IL）-supported sulfonic acids with different anions,[C_3SO_3Hmim]HSO_4,[C_3SO_3Hmim]BF_4, [C_3SO_3 Hmim]PF_6,and[C_3SO_3Hmim]CF_3SO_3,were synthesized and applied as catalysts for esterification reaction of benzoic acid. The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO_4^- shows the best catalytic activity.Only when less[C_3SO_3Hmim]HSO_4（0.3 equiv.） applied,was the product obtained with high yield of 97%.Furthermore, the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.

Proton-gradient-transfer acid complexes and their catalytic performance for the synthesis of geranyl acetate

Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterifica- tion of terpenols. These PGTACs are ＂reaction-induced self-separation catalysts＂ and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.

Preparation and properties of zirconia nanotube-supported 12-tungstophosphoric acid catalyst

Zirconia nanotube-supported H3 PW_（12）O_（40）（HPW） catalysts were obtained by loading HPW onto zirconia nanotube arrays which were prepared through anodization of zirconium foil in the mixture of formamide and glycerol（volume ratio = 1：1） containing 1 wt% NH4 F and 1 wt% H_2 O.The samples were characterized through scanning electron microscope,X-ray diffraction,infrared spectra and thermogravimetric analysis. Various factors affecting the catalytic activities have been investigated. The catalysts, prepared through pretreating the nanotube carrier at 400 ＇C, followed by loading with 35 wt% HPW and calcining at 200 ℃, possess high catalytic activities in the synthesis of fatty acid ethyl ester. Under the optimal reaction conditions, the conversion percentages of lauric acid, oleic acid and stearic acid are all higher than 98.5%.