Oxidative Dehydrogenation (ODH) of Ethylbenzene with $$\hbox {CO}_{2}$$ CO 2 and $$\hbox {N}_{2}\hbox {O}$$ N 2 O over Heteropolycompounds

• DOI: 10.1007/s12039-018-1447-y
• Publication Date: 2018-03-27T09:10:35Z
• Authors: Salem Cheknoun; Sadia Mansouri; Ouarda Benlounes; Smain Hocine
• Keywords: 0211 other engineering and technologies; 02 engineering and technology; 3. Good health

Heteropolyacids of Keggin structure, $$\hbox {H}_{3}\hbox {PMo}_{12}\hbox {O}_{40}$$ , $$\hbox {H}_{3}\hbox {PMo}_{11}\hbox {WO}_{40}$$ and the salts $$\hbox {K}_{3}\hbox {PMo}_{11}\hbox {WO}_{40}$$ and $$\hbox {K}_{2.5}\hbox {Fe}_{0.08}\hbox {H}_{0.26}\hbox {PMo}_{11}\hbox {WO}_{40}$$ were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy, Fourier transform infrared (FTIR), low-temperature nitrogen adsorption and $$^{31}$$ P MAS NMR spectroscopy. The acid-base properties were evaluated using the isopropanol decomposition. They were tested in oxidative dehydrogenation (ODH) of ethylbenzene in the temperature range 300–400 $$^{\circ }\hbox {C}$$ at atmospheric pressure with the mild oxidants carbon dioxide and nitrous oxide, the major actors in the greenhouse effect. The results show that the best compromise between conversion and selectivity is obtained for the mixed K/Fe salt of $$\hbox {PMo}_{11}\hbox {WO}_{40}$$ at a relatively low temperature, namely $$350^{\circ }\hbox {C}$$ . Synopsis:Heteropolycompounds of Keggin structure catalysed oxidative dehydrogenation of ethylbenzene with high selectivity to styrene. It was noted that acidic properties of the catalytic system, reaction conditions and catalyst composition affect the oxidative dehydrogenation reaction.