Control of nitrogen oxide (NOx) emissions by selective catalytic reduction with hydrogen over hydrophobic catalysts

The selective catalytic reduction of NO x with H 2 over noble -metal catalysts supported on hydrophobic material has been studied for the control of NO x emission from simulated stationary sources. The activity of the noble metal catalysts was found to be in the order Pt>Pd-Ru>Pd>Ru>>Au. The presence of O 2 in the feed tends to decrease the NO x conversion. The control of reaction temperature is crucial to the catalyst selectivity due to the competitive reaction between H 2 and O 2 . Optimum reaction temperature and space velocity lead to the minimum hydrogen requirement