Compositions of lean nox trap (lnt) systems and methods of making and using same

Abstract

The present disclosure relates to a substrate comprising nanoparticle catalysts and NO x storage materials for treatment of gases, and washcoats for use in preparing such a substrate. Also provided are methods of preparation of the nanoparticle catalysts and NO x storage materials, as well as methods of preparation of the substrate comprising the nanoparticle catalysts and NO x storage materials. More specifically, the present disclosure relates to a coated substrate comprising nanoparticle catalysts and NO x storage materials for lean NO x trap (LNT) systems, useful in the treatment of exhaust gases.

1 - 94 . (canceled) 
     
     
         95 . A method of treating an exhaust gas, comprising:
 flowing the exhaust gas through a conduit; and   contacting a coated substrate with the exhaust gas, the coated substrate comprising:
 a substrate; 
 a washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles bonded to a first micron-sized carrier particle, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; 
 a washcoat layer comprising reductive catalytically active micron-particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles bonded to a second micron-sized carrier particle, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle; and 
 a washcoat layer comprising NO x  trapping particles, the NO x  trapping particles comprising a micron-sized cerium oxide-containing material. 
   
     
     
         96 . The method of  claim 95 , wherein the micron-sized cerium oxide-containing material comprises cerium oxide, cerium-zirconium oxide, cerium-lanthanum oxide, cerium-yttrium oxide, cerium-zirconium-lanthanum oxide, cerium-zirconium-yttrium oxide, cerium-lanthanum-yttrium oxide, or cerium-zirconium-lanthanum-yttrium oxide. 
     
     
         97 . The method of  claim 96 , wherein the micron-sized cerium oxide-containing material comprises cerium-zirconium-lanthanum oxide or cerium-zirconium-lanthanum-yttrium oxide. 
     
     
         98 . The method of  claim 95 , wherein the washcoat layer comprising reductive catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising oxidative catalytically active micron-particles. 
     
     
         99 . The method of  claim 98 , wherein the washcoat layer comprising oxidative catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising NO x  trapping particles. 
     
     
         100 . The method claim of 95, wherein the NO x  trapping particles further comprise barium oxide impregnated in the micron-sized cerium oxide-containing material. 
     
     
         101 . The coated substrate of  claim 100 , wherein the barium oxide is impregnated in the micron-sized cerium oxide or the micron-sized cerium oxide-containing material by wet chemistry. 
     
     
         102 . The method of  claim 95 , wherein the NO x  trapping particles further comprise platinum or palladium impregnated in the micron-sized cerium oxide-containing material. 
     
     
         103 . The method of  claim 102 , wherein the platinum or palladium is plasma-generated. 
     
     
         104 . The method of  claim 102 , wherein the platinum or palladium is impregnated in the micron-sized cerium oxide-containing material by wet chemistry. 
     
     
         105 . The method of  claim 95 , wherein the NO x  trapping particles further comprise the perovskite FeBaO 3  impregnated in the micron-sized cerium oxide-containing material. 
     
     
         106 . The method of  claim 95 , wherein the NO x  trapping particles further comprise metal oxides selected from the group consisting of samarium, zinc, copper, iron, and silver oxides impregnated in the micron-sized cerium oxide-containing material. 
     
     
         107 . The method of  claim 95 , wherein the washcoat layer comprising NO x  trapping particles further comprises micron-sized aluminum oxide particles. 
     
     
         108 . The method of  claim 95 , wherein the oxidative catalytically active micron-particles comprise a material selected from the group consisting of platinum, palladium, and a platinum-palladium alloy. 
     
     
         109 . The method of  claim 95 , wherein the NO x  trapping particles further comprise zirconium oxide. 
     
     
         110 . The method of  claim 95 , wherein the first micron-sized carrier particle or the first support nanoparticle comprises aluminum oxide. 
     
     
         111 . The method of  claim 95 , wherein the second micron-sized carrier particle or the second support nanoparticle comprises cerium oxide. 
     
     
         112 . The method of  claim 95 , wherein the washcoat layer comprising the oxidative catalytically active micron-particles or the washcoat layer comprising reductive catalytically active micron-particles further comprises filler particles or boehmite particles; wherein the filler particles are metal oxide particles. 
     
     
         113 . The method of  claim 95 , wherein the conduit is configured to receive the exhaust gas from an engine configured to alternatively operate in lean-burn or rich-burn. 
     
     
         114 . The method of  claim 95 , wherein the coated substrate is housed within a catalytic converter configured to receive the exhaust gas. 
     
     
         115 . A method of treating an exhaust gas, comprising:
 flowing the exhaust gas through a conduit; and   contacting a coated substrate with the exhaust gas, the coated substrate comprising:
 a substrate; 
 a washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles embedded in a first micron-sized porous carrier, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; 
 a washcoat layer comprising reductive catalytically active micron-particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles embedded in a second micron-sized porous carrier, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle; and 
 a washcoat layer comprising NO x  trapping particles, and the NO x  trapping particles comprising a micron-sized cerium oxide-containing material. 
   
     
     
         116 . The method of  claim 115 , wherein the micron-sized cerium oxide-containing material comprises cerium oxide, cerium-zirconium oxide, cerium-lanthanum oxide, cerium-yttrium oxide, cerium-zirconium-lanthanum oxide, cerium-zirconium-yttrium oxide, cerium-lanthanum-yttrium oxide, or cerium-zirconium-lanthanum-yttrium oxide. 
     
     
         117 . The method of  claim 116 , wherein the micron-sized cerium oxide-containing material comprises cerium-zirconium-lanthanum oxide or cerium-zirconium-lanthanum-yttrium oxide. 
     
     
         118 . The method of  claim 115 , wherein the washcoat layer comprising reductive catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising oxidative catalytically active micron-particles. 
     
     
         119 . The method of  claim 118 , wherein the washcoat layer comprising oxidative catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising NO x  trapping particles. 
     
     
         120 . The method claim of  115 , wherein the NO x  trapping particles further comprise barium oxide impregnated in the micron-sized cerium oxide-containing material. 
     
     
         121 . The coated substrate of  claim 120 , wherein the barium oxide is impregnated in the micron-sized cerium oxide or the micron-sized cerium oxide-containing material by wet chemistry. 
     
     
         122 . The method of  claim 115 , wherein the NO x  trapping particles further comprise platinum or palladium impregnated in the micron-sized cerium oxide-containing material. 
     
     
         123 . The method of  claim 122 , wherein the platinum or palladium is plasma-generated. 
     
     
         124 . The method of  claim 122 , wherein the platinum or palladium is impregnated in the micron-sized cerium oxide-containing material by wet chemistry. 
     
     
         125 . The method of  claim 115 , wherein the NO x  trapping particles further comprise the perovskite FeBaO 3  impregnated in the micron-sized cerium oxide-containing material. 
     
     
         126 . The method of  claim 115 , wherein the NO x  trapping particles further comprise metal oxides selected from the group consisting of samarium, zinc, copper, iron, and silver oxides impregnated in the micron-sized cerium oxide-containing material. 
     
     
         127 . The method of  claim 115 , wherein the washcoat layer comprising NO x  trapping particles further comprises micron-sized aluminum oxide particles. 
     
     
         128 . The method of  claim 115 , wherein the oxidative catalytically active micron-particles comprise a material selected from the group consisting of platinum, palladium, and a platinum-palladium alloy. 
     
     
         129 . The method of  claim 115 , wherein the NO x  trapping particles further comprise zirconium oxide. 
     
     
         130 . The method of  claim 115 , wherein the first micron-sized carrier particle or the first support nanoparticle comprises aluminum oxide. 
     
     
         131 . The method of  claim 115 , wherein the second micron-sized carrier particle or the second support nanoparticle comprises cerium oxide. 
     
     
         132 . The method of  claim 115 , wherein the washcoat layer comprising the oxidative catalytically active micron-particles or the washcoat layer comprising reductive catalytically active micron-particles further comprises filler particles or boehmite particles; wherein the filler particles are metal oxide particles. 
     
     
         133 . The method of  claim 115 , wherein the conduit is configured to receive the exhaust gas from an engine configured to alternatively operate in lean-burn or rich-burn. 
     
     
         134 . The method of  claim 115 , wherein the coated substrate is housed within a catalytic converter configured to receive the exhaust gas. 
     
     
         135 . A method of treating an exhaust gas, comprising contacting a coated substrate with the exhaust gas, the coated substrate comprising:
 a substrate;   a washcoat layer comprising oxidative catalytically active composite nanoparticles attached to a first micron-sized support particle, the oxidative catalytically active composite nanoparticles being plasma-generated and comprising a first support nanoparticle and an oxidative catalytic nanoparticle;   a washcoat layer comprising reductive catalytically active composite nanoparticles attached to a second micron-sized support particle, the reductive catalytically active composite nanoparticles being plasma-generated and comprising a second support nanoparticle and a reductive catalytic nanoparticle; and   a washcoat layer comprising NO x  trapping particles, and the NO x  trapping particles comprising a micron-sized cerium oxide-containing material.   
     
     
         136 . A method of treating an exhaust gas, comprising contacting a coated substrate with the exhaust gas, the coated substrate comprising:
 a substrate;   a first washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles bonded to a first micron-sized carrier particle, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and   a second washcoat layer comprising reductive catalytically active micron-particles and NO x  trapping particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles bonded to a second micron-sized carrier particle, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO x  trapping particles comprising a micron-sized cerium oxide-containing material.   
     
     
         137 . A method of treating an exhaust gas, comprising contacting a coated substrate with the exhaust gas, the coated substrate comprising:
 a substrate;   a washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles embedded in a first micron-sized porous carrier, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and   a washcoat layer comprising reductive catalytically active micron- particles and NOx trapping particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles embedded in a second micron-sized porous carrier, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NOx trapping particles comprising a micron-sized cerium oxide-containing material.   
     
     
         138 . A method of treating an exhaust gas, comprising contacting a coated substrate with the exhaust gas, the coated substrate comprising:
 a substrate;   a washcoat layer comprising oxidative catalytically active composite nanoparticles attached to a first micron-sized support particle, the oxidative catalytically active composite nanoparticles being plasma-generated and comprising a first support nanoparticle and an oxidative catalytic nanoparticle;   and a washcoat layer comprising NOx trapping particles and reductive catalytically active composite nanoparticles attached to a second micron-sized support particle, the reductive catalytically active composite nanoparticles being plasma-generated and comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NOx trapping particles comprising a micron-sized cerium oxide-containing material.