Catalytic Performance of Alumina for NOx Control in Diesel Exhaust

The catalytic performance of alumina for NOx control from the exhaust of a diesel engine was investigated.

Although a slight decrease in catalytic activity was observed at the initial stage of the catalyst evaluation, more than 70% of NOx conversion was obtained at 400 °C and a space velocity of 10000 1/h for more than 2000 hours by using a honeycomb type alumina catalyst and methanol as the reducing agent.

The experimental results using synthesized exhaust gases containing SO₂ and characteristic of alumina revealed that the initial catalytic deactivation is ascribed to the accumulation of sulfur on the surface of the alumina.

We have also succeeded in improving the de-NOx performance of alumina, and more than 90% of NOx conversion can be obtained.