Role of the Acidic-basic Characters of Some Metal Oxides in the Pyrolysis of Ammonium Perchlorate

TLDR: In this paper, the acidities and basicities of metal oxides were estimated thermogravimetrically by the method of adsorption of pyridine and formic acid as probe molecules, and the activation energies of the non-catalyzed and catalyzed pyrolysis of pure ammonium perchlorate (AP) were calculated from the TG results via the Coats-Redfern equation.

Abstract: Six metal oxide samples were prepared by calcination of the corresponding precursors at 500°C for 5 h in air and were characterized by IR and XRD analyses. Their surface areas were calculated by means of the BET method. The acidities and basicities of these metal oxides were estimated thermogravimetrically by the method of adsorption of pyridine and formic acid as probe molecules. The pyrolyses of pure ammonium perchlorate (AP) and of AP mixed with (10% w/w) metal oxide were studied, in a dynamic atmosphere of N2, by thermogravimetric analysis (TG) and derivative thermogravimetric analysis. A correlation was found between the catalytic activities of the metal oxides during the pyrolysis of AP, and their acidic-basic characters. The activation energies of the non-catalyzed and catalyzed pyrolysis of AP were calculated from the TG results via the Coats-Redfern equation.