Ammonia emissions from gasoline vehicles have been confirmed an essential precursor of urban secondary aerosols. To more comprehensively understand the formation mechanisms and better control vehicle-related ammonia, this paper measured the on-road ammonia emissions from six conventional and four hybrid vehicles using a state-of-the-art Quantum Cascade Laser analyzer on urban, rural, and highway routes. The test vehicles emitted 0.01 to 4.27 mg/km of ammonia emissions, with a fleet average of 1.04 mg/km. Compared to the previous laboratory tests, the results of this study were low because of the high emission standards of the vehicles and the near-zero emissions during rural driving. Most test vehicles showed high ammonia emissions during engine warm-up, while some vehicles also had ammonia peaks during dynamic highway driving. On average, hybrid vehicles emitted 60.7% less ammonia emissions than the conventional candidates. It is confirmed that ammonia was formed when incomplete oxidation products presented on a warm catalyst. Engine warm-up, dynamic highway driving, particulate filter regeneration, and hybrid engine re-starting could be important sources. It is hypothesized that the ammonia formed on the upstream catalyst could be consumed by the downstream catalyst at moderate catalyst temperature, resulting in the near-zero ammonia emissions during rural driving.

中文翻译：

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使用量子级联激光探测器对汽油和混合动力汽车的催化剂后氨排放进行道路测量


汽油车排放的氨已被证实是城市二次气溶胶的重要前体。为了更全面地了解氨的形成机制并更好地控制与车辆相关的氨，本文使用最先进的量子级联激光分析仪在城市、农村和高速公路路线上测量了六辆传统汽车和四辆混合动力汽车的道路氨排放。测试车辆排放的氨气为 0.01 至 4.27 毫克/公里，车队平均排放量为 1.04 毫克/公里。与之前的实验室测试相比，由于车辆的排放标准高，农村驾驶的排放接近零，这项研究的结果较低。大多数测试车辆在发动机预热期间表现出高氨排放，而一些车辆在动态高速公路行驶期间也出现氨峰值。平均而言，混合动力汽车的氨排放量比传统候选汽车少 60.7%。经证实，当不完全氧化产物在温催化剂上出现时，会形成氨。发动机预热、动态高速公路驾驶、微粒过滤器再生和混合动力发动机重新启动可能是重要的来源。假设在催化剂温度适中时，上游催化剂上形成的氨可以被下游催化剂消耗，导致农村驾驶过程中氨排放接近零。