Abstract: A metal-zirconium oxide material made by sol-gel techniques from alkoxides including heterometallic alkoxides. The heterometallic alkoxides include zirconium and another metal selected from alkali metals and alkaline earth metal. Optionally, in forming this material, heterometallic alkoxides of zirconium and lanthanide metal may be included during sol-gel processing, as well as mono-metal alkoxides of these metals or zirconium.

Abstract: This invention is a method for using alumina-based metal oxide materials made by sol-gel techniques for absorbing nitrogen oxides from lean-burn engines when the exhaust gas is oxidizing, the engines may be gasoline or diesel engines. The oxide materials include precious metal like platinum. The nitrogen oxides are desorbed when the exhaust is made richer and is reduced over the precious metal with reductants in the gas like hydrocarbons. Preferably, the alumina-based metal oxide is made from certain heterometallic alkoxides which include alkali metals or alkaline earth metals or both, and also aluminum. Optionally, the preferred materials may also include oxides of lanthanides.

Abstract: This invention is a single phase metal alumina material made by sol-gel techniques from certain heterometallic alkoxides which include aluminum and at least alkali metals, and optionally alkaline earth metals and lanthanide.

Abstract: This invention is a catalyst comprising a mesoporous aluminum oxide material including precious metal. The material is made by sol-gel techniques using a neutral surfactant with alkoxides, water and alcohol to form the aluminum oxide material having an interconnected pore structure of mesoporous size. The catalyst is useful to absorb nitrogen oxides from lean-burn engines when the exhaust gas is oxidizing, which may be gasoline or diesel engines. The nitrogen oxides are desorbed when the exhaust is made richer and is reduced over the precious metal with reductants in the gas like hydrocarbons. The alkoxides include aluminum alkoxides and at least one of alkali metal and alkaline earth metal. Preferably, the alkoxides include certain heterometallic alkoxides of aluminum and alkali metals or alkaline earth metals. Optionally, the alkoxides may also include lanthanides. Preferably, the alcohol used to make the oxide has four carbon atoms, most preferably being sec-butanol.

Abstract: This invention is a metal-zirconium oxide material made by sol-gel techniques from alkoxides including heterometallic alkoxides. The heterometallic alkoxides include zirconium and another metal selected from alkali metals and alkaline earth metal. Optionally, in forming this material, heterometallic alkoxides of zirconium and lanthanide metal may be included during sol-gel processing, as well as mono-metal alkoxides of these metals or zirconium.

Abstract: The invention is a method for treating exhaust gas containing carbon monoxide, hydrocarbons, and nitrogen oxides generated by a lean burn internal combustion engine. It includes bringing the exhaust gas into contact with a particular metal-zirconium oxide material made by sol-gel processing and which includes at least 0.1 wt. % precious metal. The alkoxides include heterometallic alkoxides containing zirconium and alkali metal or alkaline earth metal. Optionally the oxide may contain a lanthanide metal. Under lean-burn conditions nitrogen oxides are absorbed on the oxide and when the oxygen concentration is lowered the absorbed nitrogen oxide are desorbed and reduced over the precious metal.