Effect of Catalytic Coatings on the Performance, Emission and Combustion Characteristics of Spark Ignition Engines

This study discusses the effect of copper, nickel and chromium coating on the spark ignition engine performance, emission and combustion characteristics. The maximum brake thermal efficiency for copper coated engine is about 5% higher than standard engine at full load and about 4% higher than the standard engine at 2800 rpm. Nitrogen oxides emission for catalytic coated engine is 7% to 20% higher than standard engine at full load. It was observed that carbon monoxide and carbon dioxide emissions of standard engine were higher than catalytic coated engines at all loads. Copper coated engine has the lowest hydro carbon emission. Catalytic coated engines have 6% to 12% higher cyclinder pressure when compared to the standard engine. The crank angle of heat release values and combustion parameters indicate that a faster heat release occured for catalyst coated engines. Similarly combustion duration of standard engine is higher than that of catalytic coated engines. Catalytic coatings increase the pre-flame reactions which lead to better and faster combustion.