Rate of reduction of nitric oxide with ammonia on coke catalysts activated with sulphuric acid

Abstract

The rate of reduction of NO on activated coke catalysts was studied in detail as a function of gas composition, temperature and reaction time. The catalyst was activated at 400 °C using sulphuric acid in amounts 100–500 wt% of the catalyst. This procedure increased the N 2 formation rate by a factor of 1.5–2.6 compared with that for the original catalyst. The N 2 formation rate increased with increasing concentration of NO and O 2but was retarded by H 2O. The effect of NH 3 concentration was marginal because the adsorption of NH 3 was much stronger than that of NO. To simulate SO 2 poisoning, the catalyst was impregnated with different amounts of H 2SO 4. The decrease in BET surface area due to salt deposition was probably the main reason for catalyst deactivation.