TY - CHAP
T1 - Unraveling the Surface Chemistry of the Heterogeneous Catalytic Decomposition of O3 for Selectivity Concerning O2 or HO• Formation
AU - López, Raciel Jaimes
AU - Reyna, Daniela Palomares
AU - Vazquez-Arenas, Jorge
N1 - Publisher Copyright:
© 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
PY - 2022
Y1 - 2022
N2 - Nowadays, the O3 decomposition on heterogeneous catalysts is highly relevant for atmospheric applications where oxygen is typically formed, and wastewater treatment where the interest is to form hydroxyl radicals (advanced oxidation processes). Although both reaction mechanisms appear not to share a relationship, the surface chemistry and phenomena arising on the catalysts seem to indicate the opposite. Here, experimental and theoretical studies proposed in the literature are revisited to determine these characteristics influencing the catalytic O3 decomposition on different materials. It is systematically found that strong Lewis sites via a chemisorption process induces oxygen formation, while physisorption involving weak Lewis sites on surface hydroxyl groups decomposes ozone into hydroxyl radicals. Oxygen vacancies could act as active sites in both cases, and the point-of-zero-charge (PZC) is crucial to preserve surface hydroxyl groups at positive pH values slightly above PZC. The regeneration of active sites depends on the multi-valent oxidation state of the surface metal. Thus, the acid character of the catalyst (Lewis), the adsorption energy of O3, HO• and other oxygenated surface groups, and the charge transfer rate of the metallic redox atoms on the surface can be regarded as molecular descriptors for the design of novel catalysts for either atmospheric or wastewater treatment applications.
AB - Nowadays, the O3 decomposition on heterogeneous catalysts is highly relevant for atmospheric applications where oxygen is typically formed, and wastewater treatment where the interest is to form hydroxyl radicals (advanced oxidation processes). Although both reaction mechanisms appear not to share a relationship, the surface chemistry and phenomena arising on the catalysts seem to indicate the opposite. Here, experimental and theoretical studies proposed in the literature are revisited to determine these characteristics influencing the catalytic O3 decomposition on different materials. It is systematically found that strong Lewis sites via a chemisorption process induces oxygen formation, while physisorption involving weak Lewis sites on surface hydroxyl groups decomposes ozone into hydroxyl radicals. Oxygen vacancies could act as active sites in both cases, and the point-of-zero-charge (PZC) is crucial to preserve surface hydroxyl groups at positive pH values slightly above PZC. The regeneration of active sites depends on the multi-valent oxidation state of the surface metal. Thus, the acid character of the catalyst (Lewis), the adsorption energy of O3, HO• and other oxygenated surface groups, and the charge transfer rate of the metallic redox atoms on the surface can be regarded as molecular descriptors for the design of novel catalysts for either atmospheric or wastewater treatment applications.
KW - Advanced oxidation process
KW - Atmospheric
KW - Heterogeneous catalysis
KW - Hydroxyl radicals
KW - Oxygen
KW - Ozone
KW - Surface activity
UR - http://www.scopus.com/inward/record.url?scp=85138208692&partnerID=8YFLogxK
U2 - 10.1007/978-3-031-07622-0_11
DO - 10.1007/978-3-031-07622-0_11
M3 - Capítulo
AN - SCOPUS:85138208692
T3 - Engineering Materials
SP - 289
EP - 306
BT - Engineering Materials
PB - Springer Science and Business Media Deutschland GmbH
ER -