Rapid Reduction of Nitric Oxide by Hydrogen in the Presence of Stainless and Ni Catalyst

Abstract

Catalytic behavior of a special stainless steel for the reduction of NO under reducing conditions was studied experimentally. The repeated heat treatment under the high-temperature reducing atmosphere produces a catalytic activation of the stainless steel. This new catalyst was named as “the stainless catalyst”. From measurements of the B.E.T. specific surface area and observations by a X-ray microanalyzer, the catalytic activation of the stainless steel is believed to result from an increase in the specific surface and the formation of a Ni layer near the surface. A detailed comparison of the observed reduction rate of NO with the calculated value, assuming a gas film diffusion control, showed the interesting result that a homogeneous-heterogeneous reaction, where NO is reduced both on the catalyst surface and in the gas phase takes place in the presence of the stainless catalyst.