Oxidation of propane over a diesel exhaust catalyst

The oxidation of propane, over a concentration range of 0.30 to 1.04 mole % in air was investigated over a commercial diesel exhaust catalyst consisting of CuO, Cr₂O₃ and Pd supported on Al₂O₃. The rate of reaction was correlated by a first order, irreversible rate function; the resulting pre-exponential factor and activation energy were 3.15 × 10⁷ cc/g-sec and 21.3 kcal/gmole, respectively. At high temperatures the reaction rate became influenced by pore diffusion. A temperature of 675°K was required to obtain 50% propane conversion. It was concluded that this catayst is unsuitable for catalytic mufflers on diesel buses since the measured value of diesel exhaust temperatures at the cataytic muffler inlet is significantly less than 675°K.