The kinetics and the parametric sensitivity of the selective catalytic reduction of NO by NH3 were investigated for a high surface area vanadia-titania aerogel. The catalyst showed high activity at low temperatures and the selectivity to N-2 was higher than 99% for all experimental conditions investigated. The addition of up to 2% H2O to the dry feed notably reduced the rate of NO conversion. The effect leveled off for higher H2O concentrations. In the absence of O-2 in the feed the activity collapsed, independently whether water was present or not. Small amounts of oxygen resulted in a sharp increase of the reaction rate, but for oxygen concentrations exceeding 4%, the increase diminished. A high tolerance with respect to sulfur dioxide was observed. The estimated activation energy amounted to 60 +/- 1 kJ/mol. The microkinetic analysis resulted in a model based on an Eley-Rideal mechanism which describes the kinetic behavior over a wide experimental range.