Technical Paper
Impact of the Gas Mixture and Aging Conditions on Formaldehyde Conversion over a Series of Commercial Pt-Based Catalysts
2018-06-26
2018-01-5021
The emission of formaldehyde and its removal has recently been brought into the focus of exhaust gas catalysis beside reduction off pollutants like hydrocarbons, carbon monoxide and nitrogen oxides. In this study, five commercial Pt-based catalysts were tested on their ability to oxidize formaldehyde under a variety of gas mixtures representing typical conditions of lean burn gas engines. In general, most of the formaldehyde could be removed almost as efficiently as carbon monoxide and much easier than saturated hydrocarbons. The catalysts were aged in different simulated exhaust gas mixtures including varying SO2 concentrations at 500 °C for 100 h to investigate a possible loss of activity due to thermal aging and poisoning. In a sulfur-free simulated exhaust gas very high conversion with no detectable loss of activity due to the aging was observed. Also small amounts of SO2 (1.75 ppm) had only minor effects on formaldehyde conversion.