ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

WO_x/ZrO₂ catalysts for the conversion of α-angelica lactone with butanol to butyl levulinates

Wirawan Ciptonugroho, Joel B. Mensah, Ghith Al-Shaal, and Regina Palkovits

Institut für Technische und Makromolekulare Chemie RWTH Aachen University, Aachen, Germany

E-mail: wirawan_ciptonugroho@staff.uns.ac.id

Received: 2 August 2022  Accepted: 16 February 2023

Abstract:

WO_x/ZrO₂ catalysts with different tungsten loadings were prepared via wet impregnation, wherein the presence of WO₃ appreciably altered the textural and structural properties. According to Raman spectroscopy, loadings as high as 15 wt% WO₃ marked the onset of WO₃-nanoparticle formation. Moreover, NH₃-TPD and DRIFT spectroscopy with pyridine adsorption revealed that 15 wt% WO₃/ZrO₂ showed the highest total number of acid centres together with the largest population of Brønsted acid sites. This material was able to achieve full conversion of α-angelica lactone in n-butanol leading to the production of 43% n-butyl levulinate and 53% pseudo-butyl levulinate after 5 h at 75 °C. The catalytic performance and selectivity towards the esters were found to be strongly related to the concentration of Lewis and Brønsted acid species.

Graphical abstract

Keywords: WO3/ZrO2; Solid acid catalyst; Brønsted acid; Levulinic acid ester

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02739-x

Chemical Papers 77 (7) 3769–3778 (2023)