Carbon monoxide is a colourless, odourless and tasteless but highly toxic gas that is produced by incomplete combustion processes. In industrial exhaust gases it frequently occurs together with volatile organic compounds (VOCs). Catalytically, CO can be oxidised to non-toxic carbon dioxide (CO2) at very low temperatures (often below 200 °C). In many exhaust gas cleaning concepts, the catalyst therefore serves a dual purpose: removing VOCs and reducing CO. Since CO is an indicator of inefficient combustion, environmental authorities worldwide demand low emission levels. Modern platinum-based precious metal catalysts are particularly effective at converting CO, even when the oxygen concentration in the exhaust gas fluctuates. Removing CO not only helps to comply with legal limits but also significantly improves the company’s environmental performance.