A new efficient catalyst was developed for remediation of ammonia in air at ambient temperature by selective catalytic oxidation (SCO). Typical NH3 SCO catalysts follows an indirect selective catalytic reduction (iSCR) route wherein the NOx products of oxidation reaction react with NH3 to produce N2 and H2O. These catalysts require elevated temperatures (&gt; 200°C) and often produces NOx byproducts. The new catalyst catalyzes the ammonia oxidation via the direct route involving the formation of hydrazinium ion with its eventual decomposition to N2 and H2O. This reaction route avoids the formation of NOx and can be carried out at lower temperatures. The NH3 SCO reaction was carried out in an operando DRIFT reactor to confirm the formation of hydrazinium ions and the mechanism of the reaction. Differential reactor was used to investigate the performance of the catalysts at different NH3 concentrations, moisture (i.e., humidity level) and reaction temperature. A NH3 conversion rate of 57 mmol1s-1g-1 catalyst was obtained at room temperature and 100 percent relative humidity for a 2183 ppm NH3 in air at GSHV of 50,000 h-1.

Selective catalytic oxidation of ammonia in air at ambient temperature: Evidence of direct N2H6+ route

255th National Meeting (2018)

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