Multiphase catalysts for selective reduction of NOx with hydrocarbons

The combustion of fuels, to meet the society demands for energy, result in the emissi of large quantities of nitrogen oxides (NOx) to the environment. These pollutants cause severe environmental problems and present a serious hazard to the health. Nowadays, two methods for the control of NOx emission are employed. The selective catalytic reduction of NOx with NH3 (SCR), (for stationary sources such as power plants) and the three way catalyst (TWC), (for mobile sources such as automobiles). These are only partial solutions and include serious drawbacks. An alternative approach to the control of NOx emissions that is currently investigated world wide is the Selective Catalytic Reduction of NO x using hydrocarbons as reductant (HC-SCR). Almost every exhaust gases of emitting sources contain low levels of unburned hydrocarbons, thus these hydrocarbons can be utilized to reduce NOx to N2. For the reasons mentioned above the development of a catalyst for this process is highly desirable