226 results about "Effective surface area" patented technology

A homogeneous ceria-based mixed-metal oxide, useful as a catalyst support, a co-catalyst and / or a getter has a relatively large surface area per weight, typically exceeding 150 m<2> / g, a structure of nanocrystallites having diameters of less than 4 nm, and including pores larger than the nanocrystallites and having diameters in the range of 4 to about 9 nm. The ratio of pore volumes, VP, to skeletal structure volumes, VS, is typically less than about 2.5, and the surface area per unit volume of the oxide material is greater than 320 m<2> / cm<3>, for low internal mass transfer resistance and large effective surface area for reaction activity. The mixed metal oxide is ceria-based, includes Zr and or Hf, and is made by a novel co-precipitation process. A highly dispersed catalyst metal, typically a noble metal such as Pt, may be loaded on to the mixed metal oxide support from a catalyst metal-containing solution following a selected acid surface treatment of the oxide support. Appropriate ratioing of the Ce and other metal constituents of the oxide support contribute to it retaining in a cubic phase and enhancing catalytic performance. Rhenium is preferably further loaded on to the mixed-metal oxide support and passivated, to increase the activity of the catalyst. The metal-loaded mixed-metal oxide catalyst is applied particularly in water gas shift reactions as associated with fuel processing systems, as for fuel cells.

Propped fractures in formations from which fluids are produced are described that have wormholes extending out into the formations from the faces of the fractures at locations distant from boreholes. Methods are given for creating such propped fractures having wormholes in which either a closed propped fracture is formed and then the wormholes are formed, or the entire fracture and channel system is formed before the closure occurs.

An algae cultivation system and method. In an embodiment, an algae cultivation system is included. The algae cultivation system can include a cultivation tank, a plurality of light transmitting elements configured to be at least partially submerged in a liquid medium disposed within the cultivation tank, wherein the light transmitting elements increase the effective surface area of the liquid medium exposed to light, and a plurality of gas injectors configured to emit gas into the liquid medium. In an embodiment a method of culturing algae is included. The method can include measuring the amount of carbon dioxide in a cultivation system and modulating the amount of light being supplied to the cultivation system based on the measured amount of carbon dioxide. In an embodiment, a method of culturing algae can include measuring the amount of light being input into a cultivation system and modulating the amount of carbon dioxide being supplied to the cultivation system based on the measured amount of light. Other embodiments are also described herein.

The present invention provides a method of making a noble metal catalyst, where the noble metal is distributed on the surface of special composite carrier particles. Nanometer sized oxide particles are first dry coated by an impact mixing process on the surface of larger alumina particles. In general, this dry coating process coats the nanometer sized particles on the surface of the alumina particles. A suitable solution of noble metal(s) compound is then soaked on the surface of the composite carrier particles. Ultimately, the noble metal compound is decomposed by calcining and noble metal particles dispersed with large effective surface area on the composite carrier particles. The resultant catalyst structure improves catalyst performance while making efficient and effective use of the expensive noble metal.