The present invention relates to a metallic nanoparticle catalyst, and more particularly, to a porous catalyst in which metallic nanoparticles are embedded in a porous oxide support, and a method for preparing the porous catalyst. To this end, a porous catalyst composition having metallic nanoparticles of the present invention includes an oxide matrix structure having mesopores and micropores; and metal or metal oxide nanoparticles embedded in the oxide matrix structure having the mesopores and micropores. Thus, metallic nanoparticle catalysts having high activity even at low temperature are realized.

The present invention relates to a metallic nanoparticle catalyst, and more particularly, to a porous catalyst in which metallic nanoparticles are embedded in a porous oxide support, and a method for preparing the porous catalyst. To this end, a porous catalyst composition having metallic nanoparticles of the present invention includes an oxide matrix structure having mesopores and micropores; and metal or metal oxide nanoparticles embedded in the oxide matrix structure having the mesopores and micropores. Thus, metallic nanoparticle catalysts having high activity even at low temperature are realized.

A nitrous oxide (N.sub.2O) removal catalyst composite is provided, comprising a N.sub.2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H.sub.2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H.sub.2-TPR). Methods of making and using the same are also provided.

A nitrous oxide (N.sub.2O) removal catalyst composite is provided, comprising a N.sub.2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H.sub.2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H.sub.2-TPR). Methods of making and using the same are also provided.

A method and a system for producing a change in a medium. The method places in a vicinity of the medium at least one energy modulation agent. The method applies an initiation energy to the medium. The initiation energy interacts with the energy modulation agent to directly or indirectly produce the change in the medium. The system includes an initiation energy source configured to apply an initiation energy to the medium to activate the energy modulation agent.

A method and a system for producing a change in a medium. The method places in a vicinity of the medium at least one energy modulation agent. The method applies an initiation energy to the medium. The initiation energy interacts with the energy modulation agent to directly or indirectly produce the change in the medium. The system includes an initiation energy source configured to apply an initiation energy to the medium to activate the energy modulation agent.

Disclosed are a metal single-atom catalyst and a method for preparing the same. The method uses a minimal amount of chemicals and is thus environmentally friendly compared to conventional chemical and/or physical methods. In addition, the method enables the preparation of a single-atom catalyst in a simple and economical manner without the need for further treatment such as acid treatment or heat treatment. Furthermore, the method is universally applicable to the preparation of single-atom catalysts irrespective of the kinds of metals and supports, unlike conventional methods that suffer from very limited choices of metal materials and supports. Therefore, the method can be widely utilized to prepare various types of metal single-atom catalysts. All metal atoms in the metal single-atom catalyst can participate in catalytic reactions. This optimal atom utilization achieves maximum reactivity per unit mass and can minimize the amount of the metal used, which is very economical.

Disclosed are a metal single-atom catalyst and a method for preparing the same. The method uses a minimal amount of chemicals and is thus environmentally friendly compared to conventional chemical and/or physical methods. In addition, the method enables the preparation of a single-atom catalyst in a simple and economical manner without the need for further treatment such as acid treatment or heat treatment. Furthermore, the method is universally applicable to the preparation of single-atom catalysts irrespective of the kinds of metals and supports, unlike conventional methods that suffer from very limited choices of metal materials and supports. Therefore, the method can be widely utilized to prepare various types of metal single-atom catalysts. All metal atoms in the metal single-atom catalyst can participate in catalytic reactions. This optimal atom utilization achieves maximum reactivity per unit mass and can minimize the amount of the metal used, which is very economical.

The disclosure relates to a photocatalytic structure. The photocatalytic structure includes a carbon nanotube structure, a photocatalytic active layer coated on the carbon nanotube structure, and a metal layer including a plurality of nanoparticles located on the surface of the photocatalytic active layer. The carbon nanotube structure comprises a plurality of intersected carbon nanotubes and defines a plurality of openings, and the photocatalytic active layer is coated on the surface of the plurality of carbon nanotubes. The metal layer includes a plurality of nanoparticles located on the surface of the photocatalytic active layer.

The disclosure relates to a photocatalytic structure. The photocatalytic structure includes a carbon nanotube structure, a photocatalytic active layer coated on the carbon nanotube structure, and a metal layer including a plurality of nanoparticles located on the surface of the photocatalytic active layer. The carbon nanotube structure comprises a plurality of intersected carbon nanotubes and defines a plurality of openings, and the photocatalytic active layer is coated on the surface of the plurality of carbon nanotubes. The metal layer includes a plurality of nanoparticles located on the surface of the photocatalytic active layer.