Ti3C2 MXenes-based catalysts for the process of α-pinene isomerization

Bartosz Środa; Anna G Dymerska; Piotr Miądlicki; Agnieszka Wróblewska; Beata Zielińska

doi:10.1039/d3ra05055f

Ti₃C₂ MXenes-based catalysts for the process of α-pinene isomerization

RSC Adv. 2023 Oct 16;13(43):30281-30292. doi: 10.1039/d3ra05055f. eCollection 2023 Oct 11.

Authors

Bartosz Środa¹, Anna G Dymerska¹, Piotr Miądlicki², Agnieszka Wróblewska², Beata Zielińska¹

Affiliations

¹ Department of Nanomaterials Physicochemistry, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin Piastów Ave. 42 71-065 Szczecin Poland bartosz.sroda@zut.edu.pl.
² Department of Catalytic and Sorbent Materials Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin Piastów Ave. 42 71-065 Szczecin Poland.

Abstract

In this study, the catalytic performance of Ti₃C₂ MXene materials in the reaction of α-pinene isomerization was demonstrated. The influence of etching agents (HF, HF/H₂SO_4, and HF/HCl; weight ratios of mixed acids: 1 : 3, 1 : 4, and 1 : 5) on removing Al atoms from MAX phase, creation of an accordion-like structure typical for MXenes and catalytic activity of the produced samples have been revealed. The MXene HF obtained by MAX phase HF treatment exhibited the highest activity (conversion of α-pinene 74.65 mol%), while materials produced with the mixed acids (HF/H₂SO₄ and HF/HCl) showed a significant reduction in the conversion of α-pinene (on average about 28-fold). However, these last samples displayed an increase of about 10 mol% in the selectivity to the most desirable product-camphene. The high activity of MXene HF is a result of a high concentration of acid sites (11.62 mmol g^-1) - the concentration of acid sites in the samples obtained by MAX phase mixed acids treatment was about 2.5-5.5 times smaller. This work proposes possible mechanisms for the α-pinene isomerization reaction on the MXene HF and on the MXene HF/H₂SO₄X : Y and MXene HF/HCl X : Y in connection with their structure.