CATALYSTS FOR ENHANCED REDUCTION OF NOx GASES AND PROCESSES FOR MAKING AND USING SAME
AssigneeBattelle Memorial Institute
InventorsCharles H. F. Peden, Feng Gao, Yilin Wang, Marton Kollar, Janos Szanyi
Life of this patent
Estimating the term…
Abstract
Cu-exchanged zeolite catalysts with a chabazite structure containing selected concentrations of alkali ions or alkaline-earth ions and a lower concentration of (Cu) ions are described and a sequential process for making. Catalysts of the present invention reduce light-off temperatures providing enhanced low-temperature conversion of NOx gases. Catalysts of the present invention also exhibit high selectivity values compared to conventional NOx reduction catalysts.
Claims20
A process for fabrication of a NOX reduction catalyst, comprising the steps of:
- loading a synthetic chabazite zeolite with an alkali (Group-I) ion or an alkaline-earth (Group-II) ion to a concentration of between about 0.01% to at or below about 5% by weight therein;
- and
- subsequently loading the synthetic zeolite with copper ions to a concentration of between about 0.01% to at or below about 2% by weight therein to form the NOx reduction catalyst with enhanced low-temperature and high-temperature activity.
A process for Selective Catalytic Reduction (SCR) of NOx gases, comprising the step of:
- catalytically reducing NOx gases in an exhaust or emission stream to a preselected level over a NOx reduction catalyst comprising a synthetic chabazite zeolite comprising a first exchange loading of an alkali (Group-I) ion or an alkaline-earth (Group-II) ion between about 0.01% to at or below about 5% by weight and a second exchange loading of a copper ion between about 0.01% to at or below about 2% by weight therein.
Dependencies are inferred from the claim text.