Mechanistic Insight into Catalytic Combustion of Ethyl Acetate on Modified CeO₂ Nanobelts: Hydrolysis–Oxidation Process and Shielding Effect of Acetates/Alcoholates

Abstract

In this study, based on the comparison of two counterparts [Mn- and Cr-modified CeO2 nanobelts (NBs)] with the opposite effects, some novel mechanistic insights into the ethyl acetate (EA) catalytic combustion over CeO2-based catalysts were proposed. The results demonstrated that EA catalytic combustion consisted of three primary processes: EA hydrolysis (C–O bond breakage), the oxidation of intermediate products, and the removal of surface acetates/alcoholates. Rapid EA hydrolysis typically occurs on surface acid/base sites or hydroxyl groups, and the removal of surface acetates/alcoholates resulting from EA hydrolysis is considered the rate-determining step. The deposited acetates/alcoholates like a shield covered the active sites (such as surface oxygen vacancies), and the enhanced mobility of the surface lattice oxygen as an oxidizing agent played a vital role in breaking through the shield and promoting the further hydrolysis–oxidation process. The Cr modification impeded the release of surface-activated lattice oxygen from the CeO2 NBs and induced the accumulation of acetates/alcoholates at a higher temperature due to the increased surface acidity/basicity. Conversely, the Mn-substituted CeO2 NBs with the higher lattice oxygen mobility effectively accelerated the in situ decomposition of acetates/alcoholates and facilitated the re-exposure of surface active sites. This study may contribute to a further mechanistic understanding into the catalytic oxidation of esters or other oxygenated volatile organic compounds over CeO2-based catalysts.

Highly efficient oxidation of ethyl lactate to ethyl pyruvate with molecular oxygen over VxOy/SBA-15 catalysts

“…Meanwhile, the desorption of lattice oxygen requires higher energy, so the desorption peak is generally above 500 °C. 37 V 2 O 5 showed a very small peak at about 150 °C, corresponding to the physically adsorbed oxygen. With the increase in desorption temperature, the lattice oxygen started desorption at about 700 °C and reached a maximum at 740 °C.…”

“…O 2 -TPD could demonstrate the ability to capture and release oxygen from samples. [35][36][37] There is a big difference in O 2 adsorption/ desorption ability between the V 2 O 5 and V x O y /SBA-15 catalysts (Fig. 6A).…”

To Promote the Catalytic Ozonation of Typical VOCs by Modifying NiO with Cetyltrimethylammonium Bromide

“…C 4 H 8 O 2 (ethyl acetate) is a versatile fine chemical product and industrial solvent, mainly used in the manufacture of paint, artificial leather, plastic products, etc. [41,42]. As shown in Figure 7a, the initial C 4 H 8 O 2 conversion rate of CTAB/NiO-2/3 can reach 95%, which exceeded that of CTAB/NiO-0 (82%), and after a 4 h reaction, the conversion rate of CTAB/NiO-2/3 decreased to about 80%, while that of CTAB/NiO-0 decreased to 68%.…”

Advanced Biological Applications of Cerium Oxide Nanozymes in Disease Related to Oxidative Damage

“…Ce ions can significantly adjust their electronic configuration, which can adapt to a given chemical environment. − The lattice structure of cerium oxide also exhibits O 2 vacancies (or defects), which can convert between CeO 2 and CeO 2– x . Cerium oxide nanoparticles play important roles in antioxidation based on switching from Ce 3+ to Ce 4+ , which mimics a variety of enzyme activities, such as those of superoxide dismutase (SOD) and catalase (CAT). − Various biological enzyme activities of cerium oxide have been discovered with roles in a number of biological fields, including biocatalysis, biomedicine, drug release, and biological scaffolds. − This review introduces biological enzyme activities of cerium oxide, including principles of activity, and discusses the latest progress in research in the field of biology (Figure ).…”