Thermal decomposition studies on copper-chromium-silver impregnated activated charcoal

Thermal gravimetric analyses (TGA) were used to examine the thermal decomposition kinetics of ASC whetlerite, a copper-chromium-silver impregnated activated charcoal. In the low temperature region (< 490 K) the proposed decomposition reaction involves the reduction of the copper chromate species into a copper chromite form accompanied by the oxidation of the carbon support to carbon dioxide. The first order decomposition rate constant was determined to be k_l = 1.22 × 10³ exp(- 4.4 × 10⁴/RT). In the high temperature region (598 K to 678 K) a supported cupric oxide species is proposed to react with the carbon support resulting in the formation of cuprous oxide and carbon dioxide. The first order decomposition rate constant for this reaction was evaluated to be k_h = 6.92 × 10^-2 exp(-3.7 × 10⁴/RT).