Enhanced esterification performance by SO42-/ZrO2 anchored Nb2O5 nanotube

SO42-/ZrO2 anchored Nb2O5 nanotubes (SO42-/ZrO2@Nb2O5-NT) are prepared via the high temperature calcination, proton exchange, exfoliation, recombination, and impregnation processes. The structures and anchoring model can be confirmed by XRD, HRTEM, and FT-IR technologies. The acidic properties and specific surface area are characterized by NH3-TPD and N2 adsorption-desorption isotherms. The catalytic performances are evaluated via an esterification reaction of acetic acid and n-butanol. The results show that SO42-/ZrO2@Nb2O5-NT have stronger acid strength and higher acid content than that of Nb2O5- NT. The optimal esterification scheme is as follows: catalyst dosage is 11 wt.%, molar ratio of alcohol to acid is 2.7:1, reaction temperature is 118 celcius, and reaction time is 7 h. The esterification rate can be reached up to 92.31% over SO42-/ZrO2@Nb2O5-NT. We have rationalized esterification performance of these selected catalysts in light of structure-property relationships, which gives useful insight for the development and application of next generation esterification catalyst.(c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.