Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1997-07-25
2001-02-27
Mayes, Curtis (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S278000, C427S404000, C427S419100, C427S419200, C427S470000, C427S533000, C427S539000
Reexamination Certificate
active
06193832
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to catalyst materials and more specifically, to a method for making dielectric catalyst materials for use in catalytic reactors which produce high electric fields or corona discharge.
2. Background Description
Corona destruction of volatile organic compounds (VOCs) is a method of disposing of noxious or toxic gases or other atmospheric contaminants or pollutants. The unwanted gas is decomposed into a less polluting gas that may be vented into the atmosphere. The unwanted gases, generally VOC, are passed over a bed of catalyst in a reactor, while a high alternating current (AC) voltage is passed across the bed to produce a corona discharge. A dielectric material catalyst in the reactor produces a stable corona and the VOCs are converted to CO
2
gas.
Typically, prior art reactors are large and expensive. Further these large reactors require, typically, at least 10 kilovolts (kV) to generate the corona.
Thus, there is a need for cheaper, smaller, more compact reactors that are effective at lower voltage.
In addition to decomposing VOCs, catalytic reactors are used with high electric fields or corona discharge to facilitate a variety of chemical reactions.
PURPOSES OF THE INVENTION
It is a purpose of the invention to provide a simplified process of making dielectric catalyst structures.
It is another purpose of the invention to provide a process of making dielectric catalyst structures having an enhanced surface area for contact with reagent gases.
It is yet another purpose of the invention to provide a process of making dielectric catalyst structures with a surface coating which protects an underlying conductive layer and enhances the surface area of the catalyst structure.
SUMMARY OF THE INVENTION
These and other objects are provided by the method of making dielectric catalyst structure of the present invention. According to a first embodiment, a layer of dielectric material having a high dielectric constant is formed on a substrate of semiconductor or nonconductor material, i.e. a material which is not essentially conductive. A layer of conducting material is then formed on the dielectric layer, which is then oxidized to form a protective coating on the conducting layer.
Preferably, the dielectric material is selected from the group consisting of barium titanate (BaTiO
3
), strontium titanate (SrTiO
3
), lead zirconium titanate (PZT), and zeolites, and the conducting layer preferably includes one or more metals selected from the group consisting of copper, gold, aluminum, titanium, tungsten, nickel, palladium, and platinum. Preferably, the step of oxidation is performed by bombarding the conducting material with ions in an oxygen-rich plasma at low radio frequency (RF) energies of about 500 electron volts or less.
In a preferred embodiment of the invention, a waste wafer, having been processed through one or several steps in fabricating electrical devices is utilized as a substrate upon which layers of high dielectric and conducting materials are formed and the conducting layer is oxidized to form a catalyst structure. In a highly preferred embodiment, the catalyst structure is joined with another such catalyst structure in substrate to substrate fashion to form a double-sided catalyst structure having exterior conducting layers with rough conditioned enhanced surface areas. Alternatively, or in addition to forming double-sided catalyst structures bonded substrate to substrate, the catalyst structure may be diced into a plurality of catalyst pieces for use in a catalyst bed of a reactor.
REFERENCES:
patent: 3598635 (1971-08-01), Sagona
patent: 3923696 (1975-12-01), Chart et al.
patent: 3928533 (1975-12-01), Beall et al.
patent: 3930890 (1976-01-01), Dietz
patent: 3966646 (1976-06-01), Noakes et al.
patent: 3979193 (1976-09-01), Sikich
patent: 4094652 (1978-06-01), Lowther
patent: 4149998 (1979-04-01), Tauster et al.
patent: 4159353 (1979-06-01), Adelsberg et al.
patent: 4450244 (1984-05-01), Domesle et al.
patent: 4465576 (1984-08-01), Negishi et al.
patent: 4557796 (1985-12-01), Druschke et al.
patent: 4703028 (1987-10-01), Steininger
patent: 4711009 (1987-12-01), Cornelison et al.
patent: 4780277 (1988-10-01), Tanaka et al.
patent: 4804796 (1989-02-01), Wang et al.
patent: 4910180 (1990-03-01), Berndt et al.
patent: 4976929 (1990-12-01), Cornelison et al.
patent: 4992407 (1991-02-01), Chakraborty et al.
patent: 5114901 (1992-05-01), Tsang et al.
patent: 5229345 (1993-07-01), Logothetis et al.
patent: 5234882 (1993-08-01), Pfefferle
patent: 5236672 (1993-08-01), Nunez et al.
patent: 5248564 (1993-09-01), Ramesh
patent: 5313089 (1994-05-01), Jones, Jr.
patent: 5316738 (1994-05-01), Kojima et al.
patent: 5371056 (1994-12-01), Leyrer et al.
patent: 5407880 (1995-04-01), Ikeda et al.
patent: 5441706 (1995-08-01), Whittenberger
patent: 5490973 (1996-02-01), Grothaus et al.
patent: 5496788 (1996-03-01), Domesle et al.
patent: 5512251 (1996-04-01), Brunson et al.
patent: 5525570 (1996-06-01), Chakraborty et al.
patent: 5525834 (1996-06-01), Fischer et al.
patent: 5604174 (1997-02-01), Friedman et al.
patent: 5609736 (1997-03-01), Yamamoto
patent: 5632961 (1997-05-01), Sheller
patent: 5696394 (1997-12-01), Jones, Jr. et al.
patent: 5721043 (1998-02-01), Summerfelt et al.
patent: 5721188 (1998-02-01), Sung et al.
patent: 5736422 (1998-04-01), Lee et al.
patent: 5756223 (1998-05-01), Cameron et al.
patent: 5776621 (1998-07-01), Nashimoto
patent: 5786097 (1998-07-01), Scanlan
patent: 5804323 (1998-09-01), McKee et al.
patent: 5837405 (1998-11-01), Tomofuji et al.
patent: 5849669 (1998-12-01), Wen
patent: 5851948 (1998-12-01), Chuang et al.
patent: 5866238 (1999-02-01), Takayama et al.
patent: 5880508 (1999-03-01), Wu
patent: 5914015 (1999-06-01), Barlow et al.
International Business Machines - Corporation
Mayes Curtis
Neff Daryl K.
LandOfFree
Method of making dielectric catalyst structures does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of making dielectric catalyst structures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of making dielectric catalyst structures will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2615094