Engineering problems in the operation of microspherical chromium oxide/alumina catalysts for the dehydrogenation of paraffins

Formation of Phases and Porous System in the Product of Hydrothermal Treatment of χ-Al2O3

“…at 150 °С in the amount of 70-80 wt % (4-61 h). Thus, as showing in [10,11], the sequence of the phase transition of the χ-Al2O3 HTT (hydrothermal treatment) can be presented by the Scheme 1. HTT HTT HTT 130-150 170-25 2 3 2…”

“…Currently, the phase transition of χ-Al 2 O 3 in hydrothermal conditions has been studied poorly, because this process is described in a small amount of research works [10,11]. Authors [10,11] establish that boehmite and gibbsite were formed in the products of hydrothermal treatment (HTT) of χ-Al 2 O 3 at the 130-150 • C. It was reported that gibbsite (γ-Al(OH) 3 This scheme is debatable, and further research is needed to clarify it.…”

“…Authors [10,11] establish that boehmite and gibbsite were formed in the products of hydrothermal treatment (HTT) of χ-Al 2 O 3 at the 130-150 • C. It was reported that gibbsite (γ-Al(OH) 3 This scheme is debatable, and further research is needed to clarify it. In this research, common factors of aluminum hydroxides formation of the phase transition of χ-Al2O3 into hydroxides and the samples porous system, resulting in the HTT of χ-Al2O3 at the temperature range of 150-200 °С in the aqueous suspension (pH = 4.0-9.2) at the appropriate saturated vapor pressure of water were studied.…”