Removal of nitrogen oxides (NOx) under the
net-oxidizing conditions is one of the most important
propositions to alleviate environmental problems.
Recently, many reports have been presented on selective NOx reduction using hydrocarbons (HCs) [1].
This process may be applicable to waste gas purification for example diesel engine exhaust.
Catalytic removal of NOx with HCs is, in general,
dependent on the kind of HCs. As the light oil
consists of many kinds of HCs (nearly 1000), it is
difficult to use them all as the source of HCs. On the
other hand, H 2 and CO, easily produced from many
kinds of the fuels, are simple reductants. Therefore,
the process of NOx removal with H 2 and CO will
find wide applications if catalysts with high NOx
removal efficiency towards this process are developed.
In the case of selective NOx reduction using HCs
on precious metals catalysts, the reaction mechanism
has not been clearly explained. Although several
reports have been published [1,2], the study of NOx
removal with H 2 and CO will give us some solutions
for understanding the reaction mechanism mentioned
above. Thus, the main object of our study is focused
on the reactions on Pt catalysts.