A fluorinated COF-encapsulated CeO2@Pt sandwich catalyst enables dual interfacial-electronic modulation for liquid-phase hydrogenation

Abstract

Efficient liquid-phase hydrogenation of nonpolar substrates is constrained by interfacial mass-transfer limitations and catalyst deactivation. Herein, we report a fluorinated sandwich-structured CeO₂@Pt@TAFA catalyst, in which Pt nanoparticles anchored on CeO₂ are encapsulated within a fluorinated covalent organic framework (TAFA-COF) shell. The TAFA shell establishes a hydrophobic microenvironment that enriches styrene and H₂, while simultaneously inducing electron-deficient Pt^δ+ species favorable for H₂ activation and CC hydrogenation. In situ DRIFTS and CO-adsorption analyses reveal a transition from strong π-complexation to upright physisorption of styrene, thereby facilitating rapid desorption and turnover. Density functional theory calculations further confirm that the TAFA shell reduces the energy barriers for H₂ dissociation and CC hydrogenation compared with uncoated catalysts. Consequently, CeO₂@Pt@TAFA achieves a turnover frequency (TOF) of 731.3 h⁻¹, outperforming both CeO₂@Pt@TPA and CeO₂@Pt by 19% and 24%, respectively, while maintaining stable performance over five cycles. This study demonstrates a fluorine-enabled interfacial engineering strategy that synergistically integrates mass-transfer promotion and electronic modulation, providing generalizable design principles for high-performance hydrogenation catalysts.