Catalytic activity of coke activated with sulphuric acid for the reduction of nitric oxide

The catalytic activity of coke activated with sulphuric acid for the reduction of nitric oxide with ammonia at 150 °C was investigated. With the original coke the yield of nitrogen after 90 min reaction was only 10% and activation of the coke by the impregnation in sulphuric acid and subsequent heat treatment at ≈450 °C markedly enhanced the activity to a nitrogen yield as much as 70%. The activity decreased in repeated runs probably because of a surface coverage effect of the water produced, but the activity could be restored by further heat treatment at 400 °C.