Regulating the Phase Transformation of Alumina From γ to α by In Situ XRD

ABSTRACT γ ‐alumina (Al 2 O 3 ), the most important component among transition alumina, is frequently used as a catalyst and catalyst support. This makes the phase transformation from γ ‐Al 2 O 3 to α ‐Al 2 O 3 a widely and deeply investigated research field. However, most reported studies have employed ex situ characterization methods, such as differential scanning calorimetry (DSC), to detect the phase transformation of Al 2 O 3 , which fails to provide direct data on the reaction process. In this work, in situ x‐ray diffraction (XRD) was used to monitor the γ ‐ to α ‐phase transformation of Al 2 O 3 in real time to determine the phase transition temperature. Additionally, the phase transformation process of Al 2 O 3 was controlled by adjusting the heating rate, sample loading amount, and reaction atmosphere in the in situ XRD setup. This study provides a new strategy for the in situ detection and regulation of crystal phase transformation in Al 2 O 3 .