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Abstract: Commercial and home prepared TiO2 samples impregnated with tungstophosphoric acid (H3PW12O40) were used for the photo-assisted degradation of 2-propanol in gas–solid regime. The characterization results evidenced a good coverage of the polyoxometalate (POM) onto the surface of TiO2 along with a marginal effect of the presence of the POM on the specific surface area, morphology and cristallinity of the samples. Propene was the main intermediate product revealed in 2-propanol photocatalytic degradation by using as photocatalysts the samples containing the POM, whereas propanone was mainly obtained when the photocatalysts was bare TiO2, both commercial or home prepared. Acetaldehyde was also found as an intermediate product along with traces of isopropyl ether, mesityl oxide and isobutyl-methyl-ketone that were also detected as gaseous products in all the runs. Carbon dioxide and water were the ultimate oxidation products. [Copyright &y& Elsevier]

Abstract: Photocatalytic degradation of 2-propanol was carried out as a probe reaction both in gas–solid and in liquid–solid systems in the presence of TiO2 both bare and impregnated with lanthanide (Sm, Gd, Ho) bis-phthalocyanines (LnPc2) used as sensitizers. Continuous and batch photo-reactors, irradiated with an equal flux of photons, were used in gas–solid and in liquid–solid systems, respectively. Propanone and acetaldehyde were the main intermediates found in both systems during 2-propanol oxidation, whereas carbon dioxide and water were the final oxidation products exclusively in the gas–solid regime. The photocatalysts exhibited significantly higher activity in the liquid–solid system than in the gas–solid one. Samples impregnated with the sensitizers were apparently more photoactive than bare TiO2. The highest photoactivity was shown by the 1.85 HoPc2–TiO2 sample. [Copyright &y& Elsevier]