The effect of manganese and cerium modification on acetaldehyde selectivity of Ti-pillared bentonites
MATERIALS CHEMISTRY AND PHYSICS, cilt.358, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 358
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.matchemphys.2026.132433
- Dergi Adı: MATERIALS CHEMISTRY AND PHYSICS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Acetaldehyde selectivity, Surface acidity, Textural properties, Ti-pillared bentonite
- Gazi Üniversitesi Adresli: Evet
Özet
In this study, titanium-pillared bentonite (Ti-PB) was synthesized from raw bentonite obtained from the Han & ccedil;& imath;l & imath; region (Middle Anatolia). Ti-PB was further modified with Mn-Cu, Ce-Mn-Cu, Ce-Cu, and Ce-Fe by combining cation exchange and incipient wetness impregnation, followed by thermal treatment. N2 physisorption, XRD, FTIR, TGA/DTA, XPS, SEM, and TEM, were used to evaluate the physicochemical and catalytic properties. All synthesized Ti-PB samples exhibited the anatase TiO2 phase. Pillaring led to a remarkable improvement in the textural properties. The Ti-PB sample calcined at 500 degrees C showed d001 value of 4.40 nm, the specific BET surface area of 346 m2 g- 1, and a micropore volume of 0.092 cm3g-1. Subsequent impregnation with Ce, Fe, Cu, and Mn caused only slight changes in surface area. TiO2 pillaring and subsequent metal doping produced a nearly uniform morphology. Compared with the Ti-PB support, catalysts impregnated with Mn, Cu, Fe, or Ce exhibited enhanced thermal stability at high temperatures. Cu impregnation promoted Lewis acidity, whereas Ce-Fe and Ce-Cu increased Br & oslash;nsted acidity. Side reactions, such as ethylene dehydration and deep oxidation to CO2 were inhibited by Mn-based catalysts, which were the most effective in suppressing these pathways at elevated temperatures. This study identifies Cuw@Ti-PB, (Cu-Mn)w@Ti-PB and (Ce-Cu-Mn)w@Ti-PB as highly effective, stable, and selective heterogeneous catalysts for the selective oxidation of ethanol to acetaldehyde. The (Cu-Mn)w@Ti-PB catalyst showed the best catalytic performance, achieving a maximum ethanol conversion of 80% and an acetaldehyde selectivity of 88% at 300 degrees C.