Clarifying solvent effect during photocatalytic glycerol conversion on TiO 2 /GQD as selective photocatalyst.

Autor: Hassan S; Egyptian Petroleum Research Institute EPRI, Nasr City, Cairo, Egypt. sarahassan14@yahoo.com., El-Hafiz DRA; Egyptian Petroleum Research Institute EPRI, Nasr City, Cairo, Egypt., Abdullah ES; Egyptian Petroleum Research Institute EPRI, Nasr City, Cairo, Egypt., Khalil MMH; Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2023 Dec 09; Vol. 13 (1), pp. 21820. Date of Electronic Publication: 2023 Dec 09.
DOI: 10.1038/s41598-023-48781-3
Abstrakt: Nowadays, dealing with the growing chemical and energy demands is important without compromising the environment. So, this work studies photocatalytic glycerol conversion (as biomass derivativ feedstock) into value-added products using an eco-friendly synthesized catalyst. Graphene quantum dots (GQDs) were prepared from available/cheap precursors like glucose via the hydrothermal method and used as a support for TiO 2 . TiO 2 /GQDs were characterized via different analytical techniques, revealing very small particle sizes of ~ 3-6 nm with a large surface area of ~ 253 m 2 /g and a band gap of ~ 2.6 eV. The prepared photocatalyst shows good efficiency during photocatalytic glycerol conversion to dihydroxyacetone (DHA). Different reaction conditions were tested: reaction time, catalyst amount, presence of oxidant (H 2 O 2 ), and biphasic media (aqueous/organic phases). Comparing a monophasic (H 2 O) photoreactor with a biphasic reactor containing 90% organic phase (ethyl acetate) and 10% aqueous phase (H 2 O and/or H 2 O 2 ) indicates that the presence of H 2 O 2 increases glycerol conversion and liquid selectivity to reach 57% and 91%, respectively after 120 min. However, it still suffers a low DHA/GA ratio (2.7). On the other hand, using a biphasic reactor in the presence of an H 2 O 2 oxidant increases the DHA/GA ratio to ~ 6.6, which was not reached in previous research. The formation of H 2 O/H 2 O 2 as micro-reactors dispersed in the ethyl acetate phase increased the average light intensity effect of the glycerol/photocatalyst system in the micro-reactors. Unlike previous work, this work presents a facile way to prepare eco-friendly/cheap (noble metal free) photocatalysts for glycerol conversion to ultrapure DHA using a biphasic photoreactor.
(© 2023. The Author(s).)
Databáze: MEDLINE
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