Direct synthesis of Zn(II) and Cu(II) coordination polymers based on 4,4′-bipyridine and 1,10-phenanthroline and evaluating their effects as catalyst on ammonium perchlorate thermal decomposition

Abstract

Two coordination polymers (CPs) material, [Zn(μ-Cl)2(μ-bpy)]∞ (bpy = 4,4′-bipyridine) and [Cu(bpy)(phen)(ClO4)2]n (phen = 1,10-phenanthroline), were prepared, and their structures were determined by single-crystal X-ray crystallography showing grid-like 2D network and 1D zigzag chain, respectively. Both CPs and their mixtures were investigated as potential catalysts for ammonium perchlorate (AP) thermal decomposition by means of thermogravimetery and differential scanning calorimetery analysis. The results revealed their significant catalytic activity by decreasing the peak temperature of AP decomposition from 434 to 300 °C and increasing evolved heat from 409 up to 1622 Jg−1. The decomposition temperature ranges of catalyzed samples have also contracted from 178 to 47 °C, almost one-third comparing to decomposition temperature range of AP. Kissinger method was used to calculate the kinetic parameters of thermal decomposition of pure and mixed AP samples. The calculated activation energy and pre-exponential factor revealed effective thermokinetic influence of CPs and their mixtures on thermal decomposition of AP, by increasing the decomposition rate constant for AP from 4.6 × 10−3 s−1 at its peak temperature (434 °C), up to 15 × 10−3 s−1 at a much lower decomposition temperature (310 °C).