CO₂ Splitting by H₂O to CO and O₂ under UV Light in TiMCM-41 Silicate Sieve

Abstract

The 266-nm light-induced reaction of CO 2 and H 2 O gas mixtures (including isotopic modifications 13 CO 2, C 18 O 2, and D 2 O) in framework TiMCM-41 silicate sieve was monitored by in situ FT-IR spectroscopy at room temperature. Carbon monoxide gas was observed as the sole product by infrared, and the growth depended linearly on the photolysis laser power. H 2 O was confirmed as the stoichiometric electron donor. The work identifies CO as the single-photon, 2-electron-transfer product of CO 2 at framework Ti centers with H 2 O acting as an electron donor, which has not been established before. O 2 was detected as coproduct by mass spectrometric analysis of the photolysis gas mixture. These results are explained by single UV photon-induced splitting of CO 2 by H 2 O to CO and surface OH radical.