Methods and devices for scrubbing gases

A method for removing one or more nitrogen oxides from the gas from an internal combustion engine, comprising:

• contacting said gas in a temperature range from about 50 to about 300.degree. C. with a gas scrubbing device comprising an intermediate storage medium, wherein the intermediate storage medium comprises:
• a porous storage material comprising at least one or more metals, metal oxides or metal alloys of Group IB and Group VIII of the periodic chart;
• and
• a catalytic material having a general formula A.sub.a(1-x) B.sub.b O.sub.4, wherein A is at least one of Mg, Ca, Mn, Fe, Ni, Co, Cu, Zn, Sn and Ti;
• B is at least one of Al, Ga, In, Co, Fe, Cr, Mn, Cu, Zn, Sn, Ti and Ni;
• a+b<3, with a, b>0, and 0.ltoreq.x .ltoreq.1;
• storing one or more nitrogen oxides in said porous storage material;
• releasing a portion of said stored nitrogen oxides when said storage medium is at a temperature above about 100.degree. C.;
• and
• reducing said released nitrogen oxides in the presence of said catalytic material.

A method for removing one or more nitrogen oxides from the gas from an internal combustion engine, comprising:

• contacting said gas in a temperature range from about 50 to about 300.degree. C. with a gas scrubbing device comprising an intermediate storage medium, wherein the intermediate storage medium comprises:
• a porous storage material comprising at least one or more metals, metal oxides or metal alloys of Group IB and Group VIII of the periodic chart;
• and
• a catalytic material having a general formula Al.sub.a1(1-x) A2.sub.a2(1-x) B.sub.b O.sub.4, wherein A1 and A2 are independently at least one of Mg, Ca, Mn, Fe, Ni, Co, Cu, Zn, Sn and Ti;
• B is at least one of Al, Ga, In, Co, Fe, Cr, Mn, Cu, Zn, Sn, Ti and Ni;
• a1+a2+b.ltoreq.3 with a1, a2, b>0 and 0.ltoreq.x<1;
• storing one or more nitrogen oxides in said porous storage material;
• releasing a portion of said stored nitrogen oxides when said storage medium is at a temperature above about 100.degree. C.;
• and
• reducing said released nitrogen oxides in the presence of said catalytic material.