posted on 2024-01-18, 08:29authored byJiří Henych, Martin Št́astný, Sylvie Kříženecká, Jan Čundrle, Jakub Tolasz, Tereza Dušková, Martin Kormunda, Jakub Ederer, Štěpán Stehlík, Petr Ryšánek, Viktorie Neubertová, Pavel Janoš
Nanoceria is a promising
nanomaterial for the catalytic
hydrolysis
of a wide variety of substances. In this study, it was experimentally
demonstrated for the first time that CeO2 nanostructures
show extraordinary reactivity toward sulfonamide drugs (sulfadimethoxine,
sulfamerazine, and sulfapyridine) in aqueous solution without any
illumination, activation, or pH adjustment. Hydrolytic cleavage of
various bonds, including S–N, C–N, and C–S, was
proposed as the main reaction mechanism and was indicated by the formation
of various reaction products, namely, sulfanilic acid, sulfanilamide,
and aniline, which were identified by HPLC-DAD, LC-MS/MS, and NMR
spectroscopy. The kinetics and efficiency of the ceria-catalyzed hydrolytic
cleavage were dependent on the structure of the sulfonamide molecule
and physicochemical properties of Nanoceria prepared by three different
precipitation methods. However, in general, all three ceria samples
were able to cleave SA drugs tested, proving the robust and unique
surface reactivity toward these compounds inherent to cerium dioxide.
The demonstrated reactivity of CeO2 to molecules containing
sulfonamide or even sulfonyl (and similar) functional groups may be
significant for both heterogeneous catalysis and environmentally important
degradation reactions.