Title: Method of making maximally dispersed heterogeneous catalysts

Abstract

A method of making a catalyst with monolayer or sub-monolayer metal by controlling the wetting characteristics on the support surface and increasing the adhesion between the catalytic metal and an oxide layer. There are two methods that have been demonstrated by experiment and supported by theory. In the first method, which is useful for noble metals as well as others, a negatively-charged species is introduced to the surface of a support in sub-ML coverage. The layer-by-layer growth of metal deposited onto the oxide surface is promoted because the adhesion strength of the metal-oxide interface is increased. This method can also be used to achieve nanoislands of metal upon sub-ML deposition. The negatively-charged species can either be deposited onto the oxide surface or a compound can be deposited that dissociates on, or reacts with, the surface to form the negatively-charged species. The deposited metal adatoms can thereby bond laterally to the negatively-charged species as well as vertically to the oxide surface. Thus the negatively-charged species serve as anchors for the metal. In the second method, a chemical reaction that occurs when most metals are deposited on a fully hydroxylated oxide surface is used to create cationic metal species that bind stronglymore » both to the substrate and to metallic metal atoms. These are incorporated into the top layer of the substrate and bind strongly both to the substrate and to metallic metal atoms. In this case, these oxidized metal atoms serve as the anchors. Here, as in the previous method, nanoislands of catalytic metal can be achieved to increase catalytic activity, or monolayers or bilayers of reactive metal can also be made. « less

Inventors:

Jennison, Dwight R ^[1]

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1. Albuquerque, NM

Issue Date:

2005-11-15

Research Org.:

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

982461

Patent Number(s):

6964936

Application Number:

US patentn application 10/383,672

Assignee:

Sandia Corporation (Albuquerque, NM)

Patent Classifications (CPCs):

B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01J - CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY

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B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01J - CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY

B01J21/04 - Alumina
B01J23/04 - Alkali metals
B01J23/10 - of rare earths
B01J23/20 - Vanadium, niobium or tantalum
B01J23/38 - of noble metals
B01J23/70 - of the iron group metals or copper
B01J35/002 - {Catalysts characterised by their physical properties}
B01J35/0046 - {Physical properties of the active metal ingredient}
B01J37/0209 - {involving a reaction between the support and a fluid}
B01J37/341 - {making use of electric or magnetic fields, wave energy or particle radiation
B01J37/349 - {making use of flames, plasmas or lasers}

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DOE Contract Number:  

AC04-94AL85000

Resource Type:

Patent

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY