An experimental investigation of catalytic oxidation of propane using temperature controlled Pt, Pd, SnO2, and 90% SnO2–10% Pt catalysts

Abstract

A stagnation-point flow reactor was used to study the catalytic activity of platinum (Pt), palladium (Pd), tin dioxide (SnO₂), and 90% SnO₂–10% Pt (by mass) to premixed propane and air reactants at atmospheric pressure. The Pt and Pd catalysts served as the baseline by which to compare catalyst performance. The stagnation surface temperature was controlled to maintain constant temperatures using an electric heater in order to eliminate heat transfer effects on catalyst performance. The activity of each catalyst was evaluated for catalyst stagnation surface temperatures ranging from 300 °C to 800 °C. Three fuel–air equivalence-ratio conditions were studied (ϕ = 0.67, 1.0 and 1.5). The CO₂, CO, O₂, and C₃H₈ in the exhaust gases were measured to quantify the activity of each catalyst. The effect of heat released by surface reaction was quantified by the heater power required to stabilize the stagnation plane at the prescribed temperature. The catalysts, excluding 100% SnO₂, exhibited comparable trends with respect to propane oxidation as a function of stagnation-plane temperature. While 100% SnO₂ showed no catalytic activity at any conditions, the 90% SnO₂–10% Pt catalyst showed significant activity to propane oxidation. The lowest catalyst activation temperature of the experiments (T_surface = 250 °C) was observed for the 90% SnO₂–10% Pt catalyst for ϕ = 1.5. The results demonstrate potential of Pt/SnO₂ as a fuel oxidation catalyst.