Dynamic Interconversion of Ga(III) and GaHx in Ga-MFI Zeolites for Efficient CO2–Cyclohexane Coupling Conversion to Aromatics

The catalytic coupling conversion of naphtha and CO2 to aromatics over metal-zeolites offers a fascinating route for aromatics production, yet, the exploitation of efficient metal-zeolite catalysts and CO2 coupled naphtha to make CO2 transformed into high-value-added chemicals remain great challenges. Herein, we synthesized a framework-anchored Ga-MFI catalyst synthesized via ligand-assisted hydrothermal crystallization, achieving 80.76% aromatic selectivity at 99.57% cyclohexane conversion (550 °C, 0.1 MPa, WHSV = 1 h-1) with over 110 h stability for CO2 and cyclohexane (as a model naphthenic compound) coupling reaction. Multimodal in situ characterization (XAFS, synchrotron XRD, and FTIR) reveals that isolated Ga(III) species undergo reversible coordination switching to GaHx under reaction conditions, dynamically mediating CO2 activation through Ga species transfer. Tetrahedrally coordinated Ga-O sites synergize with proximal Brønsted acid sites. Isotopic tracing (13CO2) demonstrates 56.4% of aromatic carbon originates. The catalyst's self-recovery capability ensures structural integrity and suppresses deactivation. This work establishes a dynamic single-site catalysis framework for a CO2 coupled alkane, advancing the design of zeolite-confined metal catalysts through precise microenvironment engineering.