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Origin of Photocatalytic Activity in Continuous Gas Phase CO 2 Reduction over Pt/TiO 2
Author(s) -
Bazzo Antonio,
Urakawa Atsushi
Publication year - 2013
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201300307
Subject(s) - photocatalysis , catalysis , chemistry , diffuse reflectance infrared fourier transform , fourier transform infrared spectroscopy , analytical chemistry (journal) , mass spectrometry , irradiation , photochemistry , phase (matter) , chemical engineering , chromatography , organic chemistry , physics , nuclear physics , engineering
The dynamic nature of continuous photocatalytic reduction of gaseous CO 2 in the presence of water vapor was studied by using Pt/TiO 2 as catalyst under UV irradiation at 353 and 423 K in the absence of sacrificial electron donors. The reaction was studied with a good time resolution (order of seconds), to monitor product concentrations by means of mass spectrometry. Two distinct photocatalytic activities, namely steady‐state and transient, were identified. The former is active at the lower temperature and only for H 2 production, whereas the latter dominates for CH 4 production. The transient activity was recovered during dark time (i.e., the light is off) in the reaction mixture, with the magnitude of recovery proportionally increasing with the duration of the dark time. Higher temperature was found to be more effective for the recovery. Furthermore, insights into deactivation and reactivation mechanisms are explained by in situ diffuse reflectance infrared Fourier transform spectroscopy study.