Titanium MXenes as Heterogeneous Catalysts for the Styrene-to-Benzaldehyde Oxidation: Influence of the Etching Conditions

Abstract

Ti3C2Tz MXenes are prepared under different etching conditions and tested as heterogeneous catalysts for the selective oxidation of styrene to benzaldehyde. A clear dependence is observed between the etching conditions (hydrofluoric acid concentration and etching time) and the surface chemistry, morphology and catalytic performance of the resulting MXenes. Under appropriate conditions, etching of the Ti3AlC2 MAX phase precursor with concentrated HF produces Ti3C2Tz MXenes with highly accessible accordion-like structures and accessible Ti−O surface terminations that can act as active species for the catalytic process, keeping up with the best catalysts reported so far for this reaction. The present study represents one of the few existing reports on catalytic properties of MXenes under mild liquid-phase conditions, paving the way for future developments of this new family of 2D materials for fine chemical applications.