Pre-equilibrium chemical reaction energy converter

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PRE-EQUILIBRIUM CHEMICAL REACTION catalyst. In one embodiment, the diode is located adjacent to ENERGY CONVERTER the catalyst cluster, while in a further embodiment, the diode is located under the catalyst, as a Substrate.

FIELD OF THE INVENTION The charge carriers travel ballistically over distances that The present invention relates to the extraction of electrical can exceed the width of appropriately fabricated Semicon or mechanical energy or coherent radiation from chemical ductor junctions, Similar to a thermionic effect. However, reactions occurring on the Surface of a catalyst before unlike the thermionic effect, the charge carriers in the case thermal equilibrium has been reached by the forms of the of the present invention need not have energy greater than released energy. the work function of the material involved. The charge carrier motion is trapped as a difference in fermi level, or

BACKGROUND INFORMATION chemical potential, between either Side of the junction. The resulting Voltage difference is indistinguishable from that of

Recent experimental observations have revealed clues to a photovoltaic collector. However, the charge carrier forces various catalytic processes occurring: 1) during the 0.01 itself into the Valence or conduction band and the circuit picoSecond time interval during which chemical reactants 15 provides a counterpart hole or electron. form bonds with the Surface of a catalyst, causing the The present invention also provides devices and methods emission of charge carriers, Such as electrons and holes; 2) for converting the energy generated by catalytic reactions to during the picoSecond time interval during which reactants mechanical motion before the energy thermalizes. In an adsorb and lose energy in quantum Steps after becoming exemplary embodiment, the converted motion is used to trapped at a potential well between an adsorbate and a move a hydraulic fluid against a resisting pressure. catalyst Surface, producing electronic friction, charge carrier Recent advances in the art of quantum wells, atomically currents and phonon emission; and 3) during the nanoSecond Smooth and longer time intervals during which reaction intermedi a degreeSuperlattices of tailoring and nanometer Scale fabrication permit of the physical parameters to favor a ates and products radiate electromagnetic energy, either particular reaction pathway while trapped on a catalyst Surface or immediately after or to enhance the efficiency(charge

of the carrier, phonon, photon) energy collector.

escaping it. These processes entail three energy releasing processes, namely: 1) charge carrier emission (electrons and The temperature of operation of a device in accordance holes), 2) phonon emission and 3) photon emission. with the present invention can be as low as hundreds of The discovery of these pre-equilibrium emissions pro degrees Kelvin, which is much lower than the typical operational temperatures of conventional thermophotovol vides new pathways to convert the high grade chemical taics and thermionic systems (1500 to 2500 Kelvin). energy available during pre-equilibrium phases into useful Moreover, the power per work. The term “pre-equilibrium” refers to the period, ultimately achievable usingmass and power per Volume however brief, during which the products of reactions have accordance with the present invention exceedsemissions

that of

fuel not yet come to thermal equilibrium. These products include 35 cells, conventional thermo-photovoltaics, and conventional energy emissions, Such as charge carriers, high frequency thermionic Systems.

phonons normally associated with the optical branch lattice vibrations and with acoustic branch vibrations of similar Furthermore, in comparison to fuel cells which require wavelength and energy; and excited State chemical product complex ducting, the devices of the present invention allow Species. mixing of fuel and air in the same duct, thereby simplifying Prior to the discovery of these rapid energy emission 40 ducting requirements.

pathways, the energies resulting from a catalytic process, The combination of high Volume and mass power density, Such as the heat of adsorption and the heat of formation, Simplicity, and lower temperature operation makes the meth were considered to be heat associated with an equilibrium ods and devices of the present invention competitive and condition. Indeed, after tens of femtoseconds, emitted 45 uniquely useful.

charge carriers have thermalized and after a few to hundreds BRIEF DESCRIPTION OF THE DRAWING of picoSeconds, emitted phonons have thermalized.

FIG. 1. Shows a cross-section of an exemplary embodi

SUMMARY OF THE INVENTION ment of a device for generating electricity in accordance In an exemplary embodiment of the present invention, the 50 with the present invention.

emissions of charge carriers, Such as electron-hole pairs, ment FIG. 2 shows a cross-section of an exemplary embodi generated by chemical activity and reactions on or within of a device for converting the energy released by a catalyst Surfaces, clusters or nanoclusters, are converted into catalytic reaction into mechanical work. electric potential. In an exemplary embodiment, Semicon FIG. 3 shows a cross-section of an exemplary embodi ductor diodes Such as p-n junctions and Schottky diodes 55 ment of a device for generating electricity piezoelectrically. formed between the catalyst and the Semiconductors are FIG. 4 shows an exemplary embodiment of an arrange used to carry out the conversion. The diodes are designed to ment for generating electricity or radiation beams in accor collect ballistic charge carriers and can be Schottky diodes, dance with the present invention.

pn junction diodes or diodes formed by various combina DETAILED DESCRIPTION tions of metal-Semiconductor-oxide Structures. The inter 60 layer oxide thickneSS is preferably less than the particular FIG. 1 shows a cross-sectional view of an exemplary ballistic mean free path asSociated with the energy loss of embodiment of a device in accordance with the present the appropriate charge carrier (e.g., hole or electron). The invention. The device of FIG. 1, includes a catalyst 105 diodes are placed in contact with or near the catalyst which is arranged on a top Surface of the device to come into nanolayer or nanocluster within a distance whose order of 65 contact with oxidizer molecules 103 and fuel molecules 102. magnitude is less than approximately the mean free path of In the exemplary embodiment of FIG. 1, the catalyst 105 can the appropriate ballistic charge carrier originating in the be comprised of platinum or palladium, the oxidizer 103 can

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be comprised of air and the fuel 102 can be comprised of having a thickness typically less than 20 nm and being hydrogen or a reactant hydrocarbon Such as methanol or Sufficiently Small So as to alter the density of electron States ethanol. Exhaust molecules 104 result from the catalyzed in the catalyst to favor the production of Substantially reaction. monoenergetic holes or electrons. The Substrate diode 109 The exemplary device of FIG. 1 comprises a pair of of and the catalyst 105 may be separated by an interlayer 106 Schottky diodes which act as charge carrier collectors, with catalyst metal that permits matching the lattice parameters of the one diode 113 being arranged on the top Surface of the to this interlayer. The catalyst 105 and interlayer 106 device, adjacent to the catalyst 105 (the “adjacent surface comprise the quantum well. The interlayer 106 must be Sufficiently thin So as to permit non-energy changing elec diode') and the other diode 109 being arranged in the tron transport into the diode. The thickness of the interlayer substrate 108, below the catalyst (the “substrate diode”). An 106 should be preferably less than 20 nanometers. insulating layer 111 is arranged between the adjacent Surface In an exemplary embodiment of a device in accordance diode 113 and the substrate 108, as shown. The diodes 109 with the present invention, the substrate diode 109 com and 113 preferably comprise a bipolar Semiconductor mate prises an n-type direct band gap Semiconductor with a band rial Such as InGaASSb with a composition chosen to opti gap chosen to favor the emission of energetic electrons. mize the chosen operating conditions. For example, the 15 In a further exemplary embodiment, the thickness or Second harmonic of a CO Stretch vibration on a catalyst cluster size (if arranged in clusters) of the catalyst layer 105 Surface at 2340 per cm energies gives a photon energy of is Sufficiently Small So as to permit the appearance of band 0.58 eV. (This matches the 0.53 eV band gap of a recently gaps, discrete electron States and catalyst properties unlike developed InCaAsSb diode described in G. W. Charache et the same material in bulk. In this case, the catalyst 105 can al., “InGaAsSb thermophotovoltaic diode: Physics be comprised, preferably, of gold, Silver, copper, or nickel evaluation,” Journal of Applied Physics, Vol. 85, No. 4, Feb. and be arranged as monolayer, 200 atom clusters. 1999). The diodes 109 and 113 preferably have relatively FIG. 2 shows an exemplary embodiment of a device in low barrier heights, such as 0.05 to 0.4 volts. accordance with the present invention in which the emis The Substrate diode 109 should be forward biased Suffi Sions of phonons generated by adsorbing and bonding ciently (e.g., up to 3 volts) to raise its conduction and 25 reactions on or within catalyst Surfaces, clusters or nano valence bands above the fermi level of the catalyst 105 so as Structures are converted into hydraulic fluid pressure. to match the energy levels of the adsorbed reactants on the In accordance with the present invention, pressures gen catalyst Surface, Such as oxygen or hydrocarbon free radi erated by phonons directed into a catalyst body on a first Side cals. This induces resonant tunneling of energy into the of the catalyst body form a phonon wave which can be substrate diode 109 by photons. The dimension of the oxide guided by the geometry of the catalyst (or Substrate upon barrier or the depletion region should be kept to less than the which the catalyst may be situated) So that the phonons ballistic transport dimension, which is on the order of 10 travel to the other Side of the Substrate and impart a preSSure nanometerS. onto a fluid. The thickness of this travel should be less than A metal such as Mg, Sb, Al, Ag, Sn Cu or Ni may be used 35 the mean distance over which the direction of the phonon to form an interlayer 106 between the catalyst 105 and the remains Substantially unperturbed. The phonons arrive at an semiconductor of the substrate diode 109. The interlayer 106 angle (a "grazing” angle) Such that the directional and Serves to provide a lattice parameter match between the asymmetric pressure of the arriving phonons appears as catalyst material and the Substrate, which in turn provides a wave motion on the other side of the catalyst body which Smooth and planar interface Surface with which to construct 40 pushes against a fluid Such as a liquid metal or Sacrificial a quantum well Structure consisting of the catalyst, the interface, causing it to move in a direction parallel to the Vacuum above and the interlayer below. A quantum well bottom Surface. An apparent negative coefficient of friction Structure with Smooth interfaces alters the density of elec between the wall and the fluid is exhibited due to the wave tron States in the directions toward the Substrate and toward motion or directed impulses along the Surface of the bottom the vacuum, So as to enhance the number of electrons with 45 of the device.

the desired energy. The thickness of the catalyst and the The exemplary device comprises a substrate 202 with top interlayer should be Small enough to permit ballistic trans and bottom Surfaces having a Saw-tooth pattern, as shown in port of charge carriers. This dimension is typically less than the cross-sectional view of FIG. 2. The bottom Surface is in 20 nanometers. Quantum well Structures with thickneSS leSS contact with a hydraulic fluid 204. As shown in FIG. 2, the than 0.5 nanometer are possible in the present State of the art. 50 Substrate can be thought of as comprising a plurality of The quantum well Structure may be constructed as an island, Sub-structures 200 having rectangular cross-sections and like a pancake on a Surface (also referred to as a "quantum arranged adjacent to each other at an angle with respect to dot”). the hydraulic fluid 204.

The device of FIG. 1 may also include a non-conducting At the top surface of the substrate, each sub-structure 200 layer 107 arranged between the substrate diode 109 and the 55 includes a layer 201 comprising a catalyst. On an exposed catalyst 105. The layer 107, which can be comprised of an Side Surface between adjacent Sub-structures, each Sub oxide, permits forward-biasing of the diode 109 without a structure 200 includes a layer 202 of material which is inert significant increase in the forward current. The layer 107 with respect to the catalyst and the reactants. The body of provides a barrier against Such forward current. An optional each sub-structure is comprised of a substrate 203, which oxide 114 barrier may also be arranged on the Surface of the 60 also acts as a phonon waveguide. Platinum can be used for device between the catalyst 105 and the surface diode 113. the catalyst layer 201 and for the Substrate 203 with air as the Electrical contacts 101, 110 and 112 are arranged as oxidizer, ethanol or methanol as the hydrocarbon reactant shown in FIG. 1. Contacts 101 and 110 serve as electrical fuel and water or mercury as the hydraulic fluid 204. The output leads for the substrate diode. Contacts 101 and 112 hydraulic fluid can also serve as a coolant for the device, are the electrical output leads for the Surface diode. 65 thereby permitting high power density operation. In the device of FIG. 1, the catalyst layer 105 may The catalyst 201 and substrate 203 may be comprised of comprise a quantum well Structure (including quantum dots) the same material, e.g., platinum. Other Substrate materials

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S 6 may be used based on Structural considerations, manufac the reactions are conducted into the piezoelectric material turability and/or impedance matching So as to maximize the 303. AS a result, a potential is induced in the piezoelectric propagation of the phonon motion into the hydraulic fluid. material 303 at the electrical contacts 302. The thickness of the platinum catalyst layer 201 and The geometry of the Substrate 303 is preferably such as to Substrate 203 should be less than the energy-changing mean focus phonons So as to enhance the nonlinearity of the free path of optical branch phonons or high frequency piezoelectric element 303. This results in self-rectification of acoustic branch phonons, which is at least of order 10 the high frequency phonons. In an exemplary embodiment, nanometers and can be as large as one micron. the piezoelectric element 303 is preferably curved and Nanofabrication methods can be used to form the saw shaped like a lens or concentrating reflector So as to focus tooth patterns on the surfaces of the Substrate 202, with the the phonons generated by the catalyst on to the piezoelectric dimension of a unit of Such pattern being as large as 1 material. The focusing of the phonons causes large ampli micron. tude atomic motions at the focus. The atomic motions By depositing the inert layerS 202 as shown, e.g., on the induced by this focusing cause the piezoelectric material to right-facing facets of the Saw-tooth pattern of the top 15 become nonlinear, causing non-linear responses Such as the Surface, a preferential direction is thereby established for generation of electricity in the material at the focus. This in reactions and thus for phonon propagation, as indicated by turn results in the piezo-material becoming a rectifier of the the arrow in FIG. 2. phonon-induced high frequency current. Acoustic, ultraSonic or gigahertz acoustic Rayleigh waves Acoustic, ultraSonic or gigahertz acoustic Rayleigh waves on the catalyst Side can be used to Stimulate the reaction rate can be used on the catalyst Side of the exemplary device of and Synchronize the emission of phonons. The waves FIG. 3 to stimulate the reaction rate and synchronize the increase the magnitude of the phonon emission and cause emission of phonons, to enhance the magnitude of the coherent emission, greatly enhancing both the peak and phonon emission and to cause coherent emission, greatly average power. enhancing both the peak and average power delivered to the In a further embodiment, a thin layer or layers of material 25 piezoelectric material 303. Acoustic Rayleigh waves accel are arranged between the Substrate and the fluid. These erate oxidation reactions on platinum catalyst Surfaces. layers are comprised of materials having acoustic imped Surface acoustic waves can be generated on the Surface of ances between that of the substrate 202 and the hydraulic the catalyst 301 using a generator (not shown). Such waves fluid 204, So as to maximize the transmission of momentum may have acoustic, ultrasonic or gigahertz frequencies. The into the hydraulic fluid and minimize reflections back into Rayleigh waves induce reactions So as to Synchronize the the Substrate 204. The material should be selected So that the reactions, which in turn Synchronizes the emission of bulk modulus and phonon propagation properties of the phonons. The result is a pulsing bunching of the reactions, material cause the phonons emerging from the Substrate to which enhances the power delivered to the piezoelectric be transmittied substantially into the fluid with minimal material 303.

reflection and energy loSS. 35 The frequency of operation of the device of FIG. 3 is In a further embodiment of a device in accordance with preferably in the GHz range and lower so that rectification the present invention, the emissions of phonons generated of the alternating currents produced by the piezoelectric by catalytic reactions are converted into electrical current by material 303 can be achieved with conventional means, Such piezo-electric effects within materials as the phonons impact as with Semiconductor diodes.

the materials. An exemplary embodiment of Such a device is 40 In a further exemplary embodiment of the present shown in FIG. 3. invention, electromagnetic radiation, Such as infrared pho The exemplary device of FIG.3 comprises a catalyst layer tons emitted by excited State products Such as highly vibra 301 arranged on a piezo-electric element 303, which is in tionally excited radicals and final product molecules, is turn arranged on a Supporting Substrate 304. The catalyst converted into electricity photovoltaically. Stimulated emis layer 301 can be implemented as a nanocluster, nanolayer or 45 Sion of radiation is used to extract the energy from the quantum well. Electrical leads 302 are provided at opposite excited State products, Such as highly vibrationally excited ends of the piezo-electric element 303 across which a radical and reaction product molecules both on the catalyst potential is developed, in accordance with the present inven Surface and desorbing from it. The extracted energy appears tion. In the exemplary embodiment of FIG. 3, the catalyst in the form of a coherent beam or a Super-radiant beam of layer 301 comprises platinum, with air as the oxidizer and 50 infra-red or optical energy. The frequencies of the radiation ethanol or methanol as the hydrocarbon reactant fuel. The correspond to fundamental (vibration quantum number piezo-electric element 303 can comprise any piezomaterial, change of 1) or overtones (vibration quantum number including Semiconductors that are not normally change 2 or greater) of the normal mode vibration frequen piezoelectric, Such as InGaAsSb. The lattice mismatch cies of the reactants. Several different frequencies may be between the Semiconductor and the platinum produces a 55 extracted simultaneously in this invention. While the result Strain, commonly called a deformation potential which ing coherent beam is useful in its own right, this high induces piezoelectric properties in Semiconductors, or fer intensity beam can also be photovoltaically converted into roelectric or piezoelectric materials with a high nonlinearity electricity. In accordance with the present invention, Such such as (Ba, Sr)TiO3 thin films, AlxGa1-xAS/GaAs and emissions are created by reactions on catalyst Surfaces, and strained layer InCaAS/GaAs (111) B quantum well p-i-n 60 are accelerated by the use of optical cavities. FIG. 4 shows StructureS. an exemplary embodiment of an electric generator for Where the piezoelectric element 303 is comprised of a performing Such a conversion.

Semiconductor, the Semiconductor becomes a diode element The device of FIG. 4 comprises one or more substrates that converts photons into electricity, collects electrons as 401 upon which a catalyst 402 is arranged in a plurality of electricity, and converts phonons into electricity. 65 islands, nanoclusters, quantum well clusters or quantum In the exemplary embodiment of FIG. 3, as the reactants dots. The catalyst clusters are Sufficiently spaced apart (e.g., interact with the catalytic layer 301, phonons generated by tens of nanometers or more) and the Substrate is made

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Sufficiently thin (e.g., less than a centimeter total optical high brightness, quasi-monochromatic, poly-chromatic thickness), So that IR absorbtion is mitigated at the frequen radiations or coherent beams.

cies of Specie emission. The assembly of catalyst clusters on In each of the above described embodiments which the substrates 401 is substantially transparent to the reaction include photovoltaic Semiconductors, the catalyst is prefer radiations. The catalyst 402 is preferably platinum or pal ably operated at a high Surface power density, e.g., in exceSS ladium. The device preferably comprises a plurality of of 10 watts per Square centimeter or with a peak Surface Substrates 401 Stacked So as to permit a volume of reactions. power density of at least one watt per Square centimeter, to The catalyst-substrate stack 401/.402 is enclosed in an enhance the efficiency of the photovoltaic Semiconductors. What is claimed is:

optical cavity having a highly reflective element 403 and a 1. A method of generating electricity comprising: less reflective element 404 arranged as shown in FIG. 4. The forming Species in highly excited States on a catalyst to optical cavity and the catalyst-substrate stack 401/402 are enable radiating electromagnetic energy before the preferably resonant to the reaction radiations or their over Species desorb, and tones. The optical cavity can be used to Stimulate overtone converting the electromagnetic energy into electricity radiation, i.e., multipole radiation where the change in with a photovoltaic collector. quantum number is 2 or more, to increase the energy of the 15 2. The method of claim 1, wherein the Species includes at radiation. The optical cavity preferably has multiple least one of an excited State radical and an exhaust product. frequencies, as in a Fabrey-Perot cavity, that are tuned to 3. The method of claim 1, wherein the catalyst operates at overtones of the Specie frequencies. a peak Surface power density greater than one watt per A fuel 407, Such as hydrogen, ethanol or methanol and an Square centimeter.

oxidizer 408, such as air, are introduced into the optical 4. The method of claim 1 comprising Storing the electrical cavity where they interact with the catalyst-Substrate Stack energy in at least one of a capacitor, a Super-capacitor and a 401/.402. Lean mixtures of fuel can be used so as to battery.

minimize resonant transfer, exchange or decay of excited 5. A method of generating electricity comprising: State vibrational energy to other Specie of the same chemical 25 forming Species in highly excited States on a catalyst hereby radiating electromagnetic energy;

makeup in the exhaust Stream, during the time these Species are in the optical cavity and the photovoltaic converter 405 converting the electromagnetic energy into electricity collects the radiation and converts it into electricity. with a photovoltaic collector; and A Stimulated emission initiator and Synchronizer device Stimulating and accelerating a reaction emission rate 412 is used to initiate and Synchronize the emissions in the using an optical cavity.

optical cavity. The device 412 can be a commonly available 6. A method of generating electricity comprising: Stimulated emission oscillator and can be coupled to the forming Species in highly excited States on a catalyst device of the present invention in known ways. The optical thereby radiating electromagnetic energy; cavity can be designed in a known way to create Stimulated converting the electromagnetic energy into electricity emission of radiation. A photovoltaic cell is typically not 35 with a photovoltaic collector; and very efficient in converting long wavelength IR photons Stimulating an overtone radiation using an optical cavity. (1000 to 5000 per centimeter) characteristic of the catalytic 7. The method of claim 6, wherein the overtone radiation reactions. The high peak power output of the device 412 includes multipole radiation with a change in quantum remedies this situation and makes the IR photovoltaic cell number of two or more.

more efficient. 8. A device for generating electricity comprising:

A photovoltaic converter 405 is placed outside the volume a catalyst to enable emission of radiation before reactants of the catalyst-substrate stack 401/402 anywhere visible to desorb;

the emitted radiation. Such a placement allows cooling the a Substrate, wherein the catalyst is arranged on the Sub photovoltaic collector 405 using known methods. The elec Strate; and trical output leads 406 of the photovoltaic collector 405 can 45 a photovoltaic converter, the photovoltaic converter being be coupled to an electrical energy Storage device 411 via a located anywhere visible to radiation emitted by reac diode 410. The output of the photovoltaic converter 405 is tions involving the catalyst. in pulses with the pulse rate typically being greater than one 9. The device of claim 8, wherein the catalyst includes at megahertz. The electrical energy Storage device 411 may least one of a nanocluster, a nanolayer and a quantum well. comprise, for example, a capacitor, Super-capacitor or bat 50 10. The device of claim 8, comprising cooling means for tery. Given the high frequency of the pulsed output, a cooling the photovoltaic converter.

capacitor used as the Storage device 411 can be quite 11. The device of claim 8 comprising an electrical Storage compact. The capacitor need only be large enough to collect device, the electrical Storage device being coupled to the the energy of a Single pulse. The energy Stored in the photovoltaic converter, wherein the electrical Storage device capacitor can thus be millions of times less than the energy 55 includes at least one of a capacitor, a Super-capacitor and a delivered by the converter 405 in one second. battery.

The chemical reactants on the catalyst Surface permit 12. A device for generating electricity comprising: overtone transitions because they are part of a “ladder” of a catalyst;

transitions and Strongly polarized on the catalyst Surface, a Substrate, wherein the catalyst is arranged on the Sub which permits all the transitions to have non-Zero dipole 60 Strate, radiation transition matrix elements. Also, the reactants have a photovoltaic converter, the photovoltaic converter being no rotational Smearing associated with free molecules in a located anywhere visible to radiation emitted by reac gas because they are attached to the Surface and can not tions involving the catalyst; and rotate. These features permit a near monochromatic over an optical cavity, wherein the catalyst is located in the tone light amplification by Stimulated emission of radiation. 65 optical cavity and wherein the optical cavity is tuned to The electromagnetic energy radiated by the Stimulation of a frequency of an excited State Species within the species, as in the embodiment of FIG. 4, can be formed into cavity.

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13. The device of claim 12 comprising an optical oscil 16. A device for generating electricity comprising: lator for Stimulating emissions in the optical cavity. a catalyst;

14. A device for generating electricity comprising: a Substrate, wherein the catalyst is arranged on the Sub a catalyst; Strate, a Substrate, wherein the catalyst is arranged on the Sub a photovoltaic converter, the photovoltaic converter being Strate, located anywhere visible to radiation emitted by reac tions involving the catalyst, a photovoltaic converter, the photovoltaic converter being wherein the catalyst includes at least one of an island, located anywhere visible to radiation emitted by reac nanocluster, quantum well cluster and a quantum dot tions involving the catalyst, and the Substrate includes a plurality of Substrates wherein the optical cavity has multiple frequencies that arranged in a Stack, thereby forming a catalyst are tuned to overtones of the Specie frequencies and Substrate Stack, wherein the catalyst-Substrate Stack is wherein the optical cavity Stimulates overtone transi tuned to at least one of a frequency or overtone thereof tions. of the radiation.

15. The device of claim 14, wherein the optical cavity is 15 a Fabrey-Perot cavity.