機車為台灣目前最普遍的私人交通工具，根據環保署統計至2009年3月底，機動車輛總數約為2,110萬輛，其中機車總數約為1,437萬輛，約佔68.1%。引擎運轉所產生的各種空氣汙染物，對人體及環境造成相當大的危害。國內目前較少針對機車觸媒轉化器污染控制效能之研究。本研究主要測量國內常用之機車觸媒轉化器效能，並透過引擎動力計測試改變引擎轉速，並利用機車廢氣分析儀與Electrical Low-Pressure Impactor（ELPI）評析觸媒轉化器對一氧化碳（CO）、碳氫化合物（HC）、氮氧化物（NOx）等氣狀污染物與粒狀污染物（PM）之處理效率，以了解目前常見之機車觸媒轉化器對排氣污染物去除情形。引擎動力計測試結果顯示，機車尾氣氣狀污染物排放濃度隨引擎轉速增加而減少，觸媒於氣狀污染物處理效能則隨之增加，而粒狀污染物數目濃度則隨引擎轉速增加而增加，觸媒處理粒狀污染物效能則隨之減少。
Motorcycle is one of the most common vehicles for land transportation in Taiwan. According to the statistical data from Ministry of Transportation and Communications, up to the end of March of 2009, there were twenty-one-million vehicles registered, including about fourteen-million motorcycles, which accounting for 68.1% of the total vehicles. Pollutants emitted from vehicles may pose serious effects to human health and the environment. Not many researches have been conducted to investigate the performance of motorcycle catalytic converter.In this study, the gaseous and particulate pollutants experimental system consisted of motorcycle engine (125 c.c.), catalytic converter, dynamometer, automotive emission analyzer (AEA), and electrical low-pressure impactor (ELPI). The gaseous pollutant concentration was measured by AEA, while the particle number concentration and size distribution were measured by ELPI. The engine rotation speed was controlled by the dynamometer. The engine was running at a rated speed of 2400, 2800, 3800, 4800 rpm.The results showed that increase of engine speed would decrease the gaseous pollutant emissions and enhance the catalytic performance. Increase of engine speed would increase the particulate matter emissions but decrease the catalytic control efficiency of particulate matter.
