Integration of plasmonic 2D Pt/TiO₂ and spectrally-selective continuous gas-lift reactor for high-efficiency photothermal rWGS

Integrating atomic-level catalyst design with macroscopic reactor engineering is pivotal for sustainable solar-to-fuel conversion. This study presents a comprehensive photothermal strategy for the reverse water–gas shift (rWGS) reaction utilizing 2D TiO₂ nanosheets decorated with Pt nanoparticles. By leveraging the Localized Surface Plasmon Resonance (LSPR) effect, the Pt-TiO₂ system extends solar absorption into the near-infrared region, achieving a CO production rate of 8.94 mmol/(g h) at a moderate bulk temperature of 350 °C. Kinetic analysis reveals a significant reduction in the apparent activation energy from 24.0 to 20.0 kJ/mol, providing the quantitative evidence of a non-thermal “kinetic overdrive” induced by hot-electron injection. While thermodynamic equilibrium predicts a parasitic methanation floor at < 400 °C, our system maintains near-unity CO selectivity (>99%), demonstrating a remarkable improvement from thermal equilibrium limits. To bridge the endothermic enthalpy gap, a continuous gas-lift reactor featuring a spectrally selective Ti-Cr-Al coating was developed, delivering a threefold enhancement in space–time yield compared to traditional batch configurations. This work highlights the synergy between plasmonic kinetic steering and spectral-selective thermal management, providing a scalable and energy-efficient framework for the valorization of anthropogenic CO₂.