Preparation, Characterization and Catalytic Activity in 2-Propanol Conversion of Potassium and Antimony Mixed Oxides
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ORIGINAL PAPER
Preparation, Characterization and Catalytic Activity in 2‑Propanol Conversion of Potassium and Antimony Mixed Oxides A. Aitlaalim1 · F. Ouanji1 · A. Benzaouak3 · M. Kacimi1 · M. Ziyad4 · L. F. Liotta2
© Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Potassium and antimony mixed oxides were obtained by calcination of the commercial potassium-antimony tartrate trihydrate K(SbO)C4H4O6.3H2O at temperatures ranging from 300 to 800 °C. The structure varied with temperature as revealed by XRD characterization. The modifications occurring during the calcination process were also studied by FT-IR and DRS spectroscopies, along with by thermal analysis (TG/DTG). The solids were tested in 2-propanol decomposition at 200 °C, used as probe reaction for the investigation of acid-basic and redox properties. The catalytic activity was function of the calcination temperature and the best 2-propanol conversion was achieved with the tartrate precursor calcined at 500 °C that crystallizes forming K SbO3 as main phase along with K 0.51Sb2.67O6.26 as secondary phase. Under N 2 the activity reached the maximum after 10 min, 80% of 2-propanol conversion was the highest value, over the sample calcined at 500 °C, but rapidly decreased with time on stream and almost declined after 1 h. In the presence of air in the reaction mixture, 85% of 2-propanol conversion was achieved at 200 °C, after 20 min under stream, with the most active sample. By increasing the calcination temperature above 500 °C, the conversion decreased, especially for the sample calcined at 800 °C showing the worse conversion, although the stability over time increased, likely due to the achievement of stable crystalline phases and crystallite sizes. In all cases, the 2-propanone selectivity was close to 100%. This behaviour confirmed the occurrence of a dehydrogenation reaction involving the basic sites typical of KSbxOy oxides along with the redox couple Sb(V)/Sb(III). Keywords KSbxOy mixed oxides · 2-propanol conversion · Dehydrogenation · 2-propanone formation
1 Introduction
* M. Kacimi [email protected] * L. F. Liotta [email protected] 1
Faculty of Sciences, Physico‑chemistry of Materials and Catalysis Laboratory, Department of Chemistry, Mohammed V University in Rabat, Avenue Ibn Battouta, B.P. 1014, Rabat, Morocco
2
Istituto Per Lo Studio Dei Materiali Nanostrutturati (ISMN)-CNR, via Ugo La Malfa, 153, 90146 Palermo, Italy
3
Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, Environmental Materials Team, ENSET, Mohammed V University in Rabat, B.P. 6207, Avenue des Forces Armées Royales, Rabat, Morocco
4
Hassan II Academy of Sciences and Technology, Km 4, (ex‑route de Zair), Avenue Mohammed VI, Rabat, Morocco
Antimony oxide is widely used in catalysis. It exhibits, in the metallic or oxidized state, excellent catalytic properties. It exists in three phases, such as antimony trioxide ( Sb2O3), antimony tetroxide (Sb2O4) and ant
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