| 汽车等的催化式排气净化器 | catalytic converter Catalytic converters are designed to clean up the exhaust fumes from petrol-driven vehicles, which are otherwise the major threat to air quality standards in congested urban streets and on motorways. Converters remove carbon monoxide, the unburned hydrocarbons and the oxides of nitrogen. These compounds are damaging to human health and the environment in a variety of ways. The converter is attached to the vehicle' s exhaust near the engine. Exhaust gases pass through the cellular ceramic substrate, a honeycomb-like filter. While compact, the intricate honeycomb structure provides a surface area of 23.000 square metres. This is coated with a thin layer of platinum, palladium and rhodium metals, which act as catalysts that simulate a reaction to changes in the chemical composition of the gases. Platinum and palladium convert hydrocarbons and carbon monoxide into carbon dioxide and water vapour. Rhodium changes nitrogen oxides and hydrocarbons into nitrogen and water, which are harmless (催化式排气净化器可用于净化汽油驱动车辆的废气，这些废气是(环境污染)的主要威胁，在拥挤的城市街道和高速公路，烟雾降低了空气的质量标准。净化器去除一氧化碳，以及未燃烧的碳氢化合物和氮氧化物。这些化合物会在各种环境下以各种方式损害人体健康。该净化器安装于汽车的尾部靠近发动机。废气通过蜂窝陶瓷载体和蜂巢状滤波器。虽然设计紧密，但复杂的蜂窝状结构提供了23平方米的表面积。表面涂有铂、钯和铑金属薄层，作为催化剂来促进化学反应。铂和钯将碳转化成二氧化碳、水蒸汽碳氢化合物和一氧化碳。铑将废气改变成氮和水，这些都是无害的氮氧化物和碳氢化合物。) |
