“…The calcination temperature is well-known to affect the structure, surface properties, and also catalytic activity of various metal oxides, 13,20,21,36,41 which motivated us to investigate such effect on the activity of m-ZrO 2 catalyst on the Gly-Gly hydrolysis. The XRD patterns of the m-ZrO 2 catalysts calcined at different temperatures (i.e., 673, 773, and 873 K) (Fig.…”