Cu/TiO2 Photo‑catalyzed CO2 Chemical Reduction in a Multiphase Capillary Reactor

Abstract

This work aimed to establish the feasibility to conduct in liquid phase the photocatalyzed conversion of CO2 to formic acid in a multiphase capillary reactor at 298 K in a 0.5M NaOH solution under Taylor-flow, which favors mass transfer (gas and liquid velocity: 0.05 and 0.08 m/s). The effect of (i) type of catalyst (Cu/TiO2 and TiO2), (ii) catalyst loading (0–1.0 g/L), (iii) catalyst addition mode (Cu/TiO2 in slurry or immobilized onto the capillary wall), (iv) radiation wavelength (254 nm, 365 nm and visible light), was studied. The synthesized catalysts exhibited anatase phase and the Cu content was 3.75% w/w.