Propane gas removal material

Abstract

A propane gas utilization system includes: a housing having propane gas; and a propane leak protection material having a catalyst, scavenger and / or oxidizer of propane gas arranged in the housing and comprising at least one of the following: (a) an oxide material having at least one composition of formula (I): Ru1-xMxO2 (I), where 0 lt; x is less than or equal to 0.1, and M is Ag, K, Pt, Rh or Ir, or (b) an oxide material having at least one composition of formula (II): Co3-xMxO4 (II), where 0 lt; or (c) an oxide material having at least one composition of formula (III): MM'xOy (III), where x is the stoichiometric ratio of M 'to M, 0 < = x < = 1.5, y is the stoichiometric ratio of O to M, 1 < = y < = 3, M is an alkali metal, and M' (if xgt; 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au or Cr, or (c) an oxide material having at least one composition of formula (III): MM 'xOy (III), where x is the stoichiometric ratio of M' to M, 0 < = x < = 1.5, y is the stoichiometric ratio of O to M, 1 < = y < = 3.

Description

Technical Field

[0001] The present disclosure relates to materials for propane oxidation and / or scavenging to prevent unwanted propane accumulation in propane gas utilization devices or systems, methods for identifying such materials, and methods for utilizing such materials.

[0002] Background

[0003] A heat pump is an energy-efficient alternative to separate furnace and air conditioning systems. A heat pump uses electricity to transfer heat from a cool space to a warm space, further cooling the cool space and further warming the warm place. Some heat pumps utilize propane gas, which can accumulate over time and pose a safety hazard due to the flammability of propane. The same risk may be encountered in other propane gas utilization systems. Mitigating this risk is desirable. Summary of the Invention

[0004] In one embodiment, a propane gas utilization system is disclosed. The system may include: a housing containing propane gas; a propane leak prevention material that includes a catalyst, scavenger, and / or oxidizer for the propane gas disposed in the housing and includes at least one of the following: (a) an oxide material having a composition of at least one of formula (I):

[0005] Ru 1-x M x O2 (I),

[0006] wherein: 0 < x ≤ 0.1, and M is Ag, K, Pt, Rh, or Ir, or

[0007] (b) an oxide material having a composition of at least one of formula (II):

[0008] Co 3-x M x O4 (II),

[0009] wherein: 0 < x ≤ 0.3, and M is Pd, Cu, or Sr, or

[0010] (c) an oxide material having a composition of at least one of formula (III):

[0011] MM’ x O y (III),

[0012] wherein: x is the stoichiometric ratio of M' to M, 0 ≤ x ≤ 1.5, y is the stoichiometric ratio of O to M, 1 ≤ y ≤ 3, M is an alkali metal, and M' (if x > 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, or Cr.

[0013] The material can be configured as a coating on at least one surface of a housing. The material can be a scavenger and can comprise at least one oxide of formula (II) or (III). The material can form a multi-layer coating, with each layer having the same composition. The material can comprise an alkali metal oxide. M in formula (I) or (III) can be K. The material can be constructed as a replaceable component of a propane gas utilization system. The material can comprise at least one compound of formula (III), where M' can be a transition metal and M is Na, K, Rb or Cs.

[0014] In another embodiment, a propane gas catalyst is disclosed. The catalyst can comprise at least one of the following:

[0015] (a) an oxide material having a composition of at least one of formula (I):

[0016] Ru 1-x M x O2(I),

[0017] where: 0 < x ≤ 0.1, and M is Ag, K, Pt, Rh or Ir, or

[0018] (b) an oxide material having a composition of at least one of formula (II):

[0019] Co 3-x M x O4(II),

[0020] where: 0 < x ≤ 0.3, and M is Pd, Cu or Sr, or

[0021] (c) an oxide material having a composition of at least one of formula (III):

[0022] MM’ x O y (III),

[0023] where: x is the stoichiometric ratio of M' to M, 0 ≤ x ≤ 1.5, y is the stoichiometric ratio of O to M, 1 ≤ y ≤ 3, M is Na, K, Rb or Cs, M' (if x > 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au or Cr, and the catalyst can be configured to increase the rate of propane gas oxidation without being consumed in the reaction.

[0024] The catalyst can be a propane gas catalyst for a heat pump system. The catalyst can form a layer of nanoparticles. The catalyst can comprise only oxides of formula (I). The catalyst can be arranged as a multi-layer coating. Each layer of the multi-layer coating can comprise one or more compounds of the same formula (I), (II) or (III).

[0025] In yet another embodiment, the propane gas scavenger can comprise at least one of the following

[0026] (a) an oxide material having a composition of at least one of formula (I):

[0027] Ru 1-x M x O2(I),

[0028] wherein: 0 < x ≤ 0.1, and M is Ag, K, Pt, Rh or Ir, or

[0029] (b) an oxide material having a composition of at least one of formula (II):

[0030] Co 3-x M x O4(II),

[0031] wherein: 0 < x ≤ 0.3, and M is Pd, Cu or Sr, or

[0032] (c) an oxide material having a composition of at least one of formula (III):

[0033] M a M’ x O y (III),

[0034] wherein: x is the stoichiometric ratio of M' to M, 0 ≤ x ≤ 1.5, y is the stoichiometric ratio of O to M, 1 ≤ y ≤ 3, M is an alkali metal, M' (if x > 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au or Cr, and the scavenger is configured to selectively react with propane gas to convert the propane gas into a composition having a density lower than that of propane gas.

[0035] The scavenger can be a propane gas scavenger for a heat pump system. The scavenger can be a replaceable component of a heat pump system. The scavenger can form a layer of nanoparticles. The scavenger can comprise at least one compound of formula (III), wherein M' can be a transition metal. The scavenger can comprise a mixture of compounds of formula (II) and (III). Brief Description of the Drawings

[0037] Figures 1A-1C Shows a non-limiting example of a heat pump system employing the materials disclosed herein;

[0038] Figure 2 Shows an exemplary algorithm for stability screening of decomposition products;

[0039] Figures 3A-3CRelative reaction energy diagram ε(x) for several non-limiting examples of materials disclosed herein and reference material Co3O4 is shown;

[0040] Figures 4A-4I A material reactivity evaluation diagram showing non-limiting examples of materials disclosed herein relative to reference materials Co3O4 and RuO2, respectively;

[0041] Figure 5 A material stability assessment chart is shown, which includes red flag materials marked with an x ​​and the reason for the red flag in the legend;

[0042] Figure 6 Plots showing stability evaluation, weighted reactivity, and cost for materials studied in search space A;

[0043] Figure 7 Plots showing stability evaluation, weighted reactivity, and cost for materials studied in search space B;

[0044] Figure 8 Plot showing the stability evaluation, weighted reactivity, and cost of the materials studied in the search space C;

[0045] Detailed Description

[0046] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show the details of a particular component. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but only as a representative basis for teaching those skilled in the art to adopt the present embodiment in various ways. As will be understood by those of ordinary skill in the art, the various features shown and described with reference to any one of the drawings may be combined with the features shown in one or more of the other drawings to produce an embodiment that is not explicitly shown or described. The combination of features shown provides a representative embodiment for a typical application. However, various combinations and modifications of features consistent with the teachings of the present disclosure may be required for specific applications or implementations.

[0047] Except for the examples or otherwise explicitly stated, all numerical quantities in this specification indicating the amount of material or reaction conditions and / or conditions of use should be understood as modified by the word "about" to describe the broadest scope of the present invention. It is generally preferred to practice within the stated numerical limits. In addition, unless otherwise explicitly stated: percentages, "parts" and ratio values ​​are all by weight; describing a group or class of materials as suitable or preferred for a given purpose associated with the present invention means that a mixture of any two or more members of the group or class is also suitable or preferred; the description of ingredients in chemical terms refers to the ingredients when added to any combination specified in the specification, and does not necessarily exclude chemical interactions between the ingredients of the mixture once mixed.

[0048] The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein and to normal grammatical variations of the initially defined abbreviation. Unless expressly stated otherwise, measurements of properties shall be determined by the same techniques as previously or subsequently cited for the same property.

[0049] It must also be noted that, as used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to a component in the singular is intended to include plural components.

[0050] As used herein, the terms "substantially", "generally" or "about" indicate that the amount or value in question may be a specified specific value or some other value in its vicinity. Typically, the term "approximately" indicating a value is intended to indicate a range within + / -5% of the value. As an example, the phrase "about 100" indicates a range of 100+ / -5, i.e., a range of 95 to 105. Typically, when the term "approximately" is used, it can be expected that similar results or effects according to the present invention can be obtained within a range of + / -5% of the indicated value. The term "substantially" may modify a value or relative property disclosed or claimed in the present disclosure. In this case, "substantially" may indicate that the value or relative property it modifies is within a range of ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the value or relative property.

[0051] It should also be understood that integer ranges explicitly include all intermediate integers. For example, the integer range 1-10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4, ... 97, 98, 99, 100. Similarly, when any range is required, the intermediate numbers that are the difference between the upper and lower limits divided by the increment of 10 can be used as alternative upper or lower limits. For example, if the range is 1.1 to 2.1, the following numbers 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 and 2.0 can be selected as lower or upper limits.

[0052] In the embodiments described herein, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rate, etc.) can be implemented with plus or minus 50% of the values ​​shown rounded or truncated to two significant figures of the values ​​provided in the examples. In one refinement, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rate, etc.) can be implemented with plus or minus 30% of the values ​​shown rounded or truncated to two significant figures of the values ​​provided in the examples. In another refinement, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rate, etc.) can be implemented with plus or minus 10% of the values ​​shown rounded or truncated to two significant figures of the values ​​provided in the examples.

[0053] For all compounds indicated by empirical chemical formulas with multiple letter and number subscripts (e.g., CHO), the subscript value may be rounded or truncated to two significant figures plus or minus 50% of the indicated value. For example, if CHO is indicated, the chemical formula of the compound is C (0.8-1.2) H (1.6-2.4) O (0.8-1.2) In one refinement, the subscript value may be rounded or truncated to two significant figures plus or minus 30% of the indicated value. In another refinement, the subscript value may be rounded or truncated to two significant figures plus or minus 20% of the indicated value. The terms "compound" and "composition" are used interchangeably.

[0054] The term "and / or" used herein means that all elements of the group may be present, or only one may be present. For example, "A and / or B" means "only A is present, or only B is present, or both A and B are present". In the case of "only A is present", the term also covers the possibility that B does not exist, that is, "only A is present, but B is not present".

[0055] It should also be understood that the present invention is not limited to the specific embodiments and methods described below, as specific components and / or conditions may of course vary. In addition, the terminology used herein is only used to describe specific embodiments of the present invention and is not intended to limit the present invention in any way.

[0056] The term "comprising" is synonymous with "including," "having," "containing," or "characterized by." These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps.

[0057] The phrase "consisting of" excludes any element, step, or ingredient not specified in the claim. When this phrase appears in a clause in the body of a claim, rather than immediately following the preamble, it limits only the elements listed in that clause; other elements are not excluded from the claim as a whole.

[0058] The phrase "consisting essentially of" limits the scope of a claim to the specified materials or steps and to those materials or steps that do not materially affect the basic and novel characteristic(s) of the claimed subject matter.

[0059] With respect to the terms "comprising," "consisting of," and "consisting essentially of," when one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms.

[0060] The term "one or more" means "at least one," while the term "at least one" means "one or more." The terms "one or more" and "at least one" include "plurality" as a subset.

[0061] Describing a group or class of materials as suitable for a given purpose in connection with one or more embodiments means that mixtures of any two or more members of the group or class of materials are suitable. Descriptions of ingredients in chemical terms refer to the ingredients when added to any combination specified in the specification and do not necessarily preclude chemical interactions between the ingredients of the mixture once mixed. The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein and to normal grammatical variations of the initially defined abbreviation. Unless expressly stated otherwise, measurements of properties are determined by the same techniques as previously or later referenced for the same property.

[0062] A heat pump is a device or system that can replace furnaces and air conditioners in almost any climate. Heat pumps do not generate heat, they transfer heat. A heat pump is an electrical device that transfers heat from a cool space to a warm space, causing the warm space to warm up and the cool space to cool down. During the heating season, a heat pump transfers heat from the cool outdoors into a home or building. During the cooling season, a heat pump transfers heat from the home or building to the outdoors.

[0063] There are several types of ducted heat pumps: air-to-air, water-source, and geothermal. A heat pump collects heat from the air, water, or ground outside the house and transfers it to the house. Other types of heat pumps include ductless heat pumps.

[0064] Heat pumps are considered very efficient; a typical air source heat pump can reduce the electricity used to heat a single home by about 50% compared to a typical forced air furnace or baseboard heater. Another advantage of heat pumps over standard central air conditioning units is their ability to effectively dehumidify the air, which reduces energy use and provides cooler comfort in the summer.

[0065] Traditional heat pumps use materials that are close to phase change to transfer heat from one area to another, such as transferring heat from outside to inside in winter. To reduce environmental impact, some applications require simple hydrocarbons such as propane that operate near the liquid-to-gas transition. Propane is a gas with the molecular formula C3H8 that was commercialized more than 100 years ago. It is a gas at standard temperature and pressure, but can be compressed to a transportable liquid. Propane is denser than air. The density of propane gas at 25°C (77°F) is 1.808kg / m 3 , which is about 1.5 times the density of air at the same temperature. The density of liquid propane at 25°C (77°F) is 0.493 g / cm 3 , which is equivalent to 4.11 pounds per U.S. liquid gallon, or 493 g / L. Propane expands 1.5% every 10° F. Therefore, the density of liquid propane at 60° F (15.6° C) is about 4.2 pounds per gallon (504 g / L).

[0066] There are risks associated with using propane. Propane can accumulate in spaces with low gravity, such as near the floor of a building. Propane is usually stored in tanks under pressure at room temperature. If any leaks occur in the tanks, the evaporated gas will sink into any enclosed area and may accumulate in one place, posing a fire hazard. The risk of explosion and fire is greater if the propane utilization unit is located underground because, due to the density of propane, the three-carbon alkane gas is less likely to move outside the building and will accumulate instead.

[0067] For example, a heat pump may emit 3-20 grams of propane per year. For a utility basement with a volume as small as 10 cubic meters (12.75 kg of air), the propane accumulation will be as high as about 1500 ppm / year. For reference, the lower explosive limit (LEL) and therefore safety limit of propane is 2100 ppm at room temperature.

[0068] In addition to heat pumps, propane is used in other systems and devices such as portable stoves and grills, as a refrigerant, a fuel for industrial and domestic purposes, as a motor vehicle fuel, a marine fuel, in blowtorches, as a hot air balloon fuel, etc.

[0069] The combustion hazard of propane is recognized, and many catalyst materials that can dehydrogenate propane have been identified in the literature. Typical methods for vaporized propane explosion focus on improving selectivity to dehydrogenate propane and produce propylene more selectively. A known catalyst is, for example, ruthenium oxide (RuO2). Ruthenium is a rare transition metal and platinum group metal. Ruthenium is also one of the most expensive metals in the world. Therefore, its supply is limited. Another known catalyst is cobalt tetroxide (Co3O4). In order to improve the performance of Co3O4, Ni or other elements are usually doped, which increases the price. In addition, due to the widespread use of Co3O4 in battery cathodes, the price of Co3O4 is expected to rise.

[0070] Therefore, there is a need to identify additional reliable, low-cost materials and / or methods to prevent the hazards associated with propane leaks, particularly underground leaks. There is also a need to identify a material that can be used over a long period of time, such as at least 10 to 20 years, over the life of a heat pump or other propane utilizing device.

[0071] In one or more embodiments, a material is disclosed. The material comprises a propane gas catalyst, a propane gas scavenger, a propane gas oxidant, or a combination thereof. The material can be incorporated into a propane application. A non-limiting example application can be a propane gas utilization device or system. A heat pump is only a non-limiting example, and other systems and devices discussed further herein are contemplated. The device or system can be located below ground or below ground in a house, building, or structure (e.g., a heat pump).

[0072] Figure 1A A schematic diagram of a non-limiting embodiment of a heat pump or heat pump system 20 is shown, and its installation in a cellar or basement 50 of a house or building. The heat pump 20 has a housing 22, which is configured to include the various components of the heat pump 20. The housing 22 may include a refrigerant circuit 24, a ventilation / exhaust duct 26 (through which exhaust gas 27 enters and / or leaves the cellar or basement 50), and a gas seal 30. The housing 22 may also include additional lines, pipes, connectors, and tubes configured to deliver propane gas to the housing 22. The heat pump system 20 may also include a propane source, such as a propane gas inlet or a propane gas tank. The housing 22 also includes the disclosed material 28, as a separate component, a coating, a layer on one or more surfaces of the housing, a portion of the housing exterior (e.g., a pipe in a line), various components of the heat pump, and / or a basement surface.

[0073] Material 28, also referred to as material X, may be suitable for (a) catalyzing a propane gas oxidation reaction and returning to its natural state X after the oxidation reaction is complete to oxidize additional amounts of propane. Material 28 may be suitable for (b) a scavenging reaction, in which material X selectively reacts with propane gas to be converted into a secondary material containing propane, preventing propane from accumulating in the air. Material 28 may be suitable for (c) containing such a high excess of oxygen that the material oxidizes propane and produces carbon dioxide by self-reduction; it is consumable in this reaction. The (c) oxidant may be classified as a scavenger because the material is consumed during the reaction.

[0074] Heat pump system 20 or another propane gas utilization system implementing materials disclosed herein can include optional heat source 32. Non-limiting heat source 32 can be a battery-powered resistance heater. Heat source 32 can improve the catalytic activity of the material, because high temperatures of about 100-300, 120-280 or 150 to 250°C can enhance the conversion of propane into CO2 and / or other "lighter" products. Heat source 32 helps control the reaction rate. The degree of heating can be adjusted to increase the reaction rate without approaching the ignition point of propane. The term "lighter" product refers to any chemical substance with a density lower than that of propane, which can be safely dissipated into the atmosphere, rather than accumulating below the ground, in heat pump system 20, basement 50 or a combination thereof. "Lighter" products will not sink into the bottom or floor, and will not accumulate. On the contrary, "lighter products" will be derived from the system, such as through ventilation / exhaust duct 26.

[0075] In addition, during operation of the heat pump 20 or another propane gas utilization system, the material is maintained below the ignition point of propane. The ignition point of propane in air is 493 to 549°C (920 to 1020°F). The material can be selected so that the system does not undergo reactions with the highest spontaneity (reaction free energy) to avoid generating additional heat that may increase the risk of fire. To further reduce the risk of fire, the material can include one or more heat dissipation and / or heat removal additives. Non-limiting examples can include one or more heat sinks, heat sinks, etc.

[0076] Table 1 below summarizes the reactions of materials X(a)-(c) with propane gas.

[0077] Table 1 – Reaction mechanism of material X (a) – (c) with propane gas

[0078] reaction describe <![CDATA[X+C3H8+5O2→X+4H2O+3CO2]]> (a) Oxidation of propane using material X (catalyst) <![CDATA[X+C3H8→XC3H8]]> (b) Scavenging reaction with material X (scavenging material) <![CDATA[XO 10 +C3H8→X+4H2O+3 CO2]]> (c) Oxidation reaction with material X (strong oxidant)

[0079] The material is designed to minimize spontaneous reactions with air, CO2, and water vapor. Reactions with any of these may result in a shorter than expected service life of the material. For example, since CO2 is one of the oxidation products of propane, the material's CO2 reactivity should be relatively low. Likewise, moisture or water vapor may be present in the heat pump environment, so the material's reactivity with water vapor is relatively low. The reactions are summarized in Table 2 below.

[0080] Table 2 – Adverse reactions of material X in heat pump systems

[0081] reaction describe <![CDATA[X+O2→XO2]]> Spontaneous reaction of material X in air <![CDATA[X+CO2→XC O 2]]> Spontaneous reaction of material X with carbon dioxide <![CDATA[X+CO2→XCO2]]> Spontaneous reaction of material X with water vapor

[0082] The material is configured to maintain its catalytic, oxidative and / or scavenging capabilities for at least 10 to about 20 years. Alternatively, the material may be configured to last for a shorter period of time and included in the device or system so that the material can be removed and replaced, such as during routine maintenance inspections / cycles (e.g., every 1, 5, 10, or 15 years).

[0083] The material may comprise one or more materials / compounds of formula (I), (II) and / or (III). The materials / compounds of formula (I), (II) and / or (III) may be catalysts, scavengers, oxidants (strong oxidants or superoxidants) and / or propane leak prevention materials for propane capture, conversion, removal, oxidation and / or catalysis. The material may be a propane leak prevention material.

[0084] Catalyst refers to a material that participates in a catalytic reaction. A catalyst can catalyze the propane oxidation reaction, causing it to become (one or more) "lighter" materials as defined herein, and to return to its original state over time to oxidize additional amounts of propane. The catalyst may not be consumed in the oxidation reaction. The catalyst may work by providing a different pathway for the propane oxidation reaction that has a lower activation energy than the uncatalyzed pathway. The catalyst may increase the rate of the propane oxidation reaction.

[0085] The scavenger reacts with the propane gas to convert it into another material containing propane molecules. Thus, the scavenger can capture the propane molecules and form a third material with the propane, thereby removing the propane from the system. The scavenger can be consumable in the conversion reaction. The scavenger can selectively target the propane gas molecules.

[0086] An oxidant or superoxidant is a material that contains excess oxygen so that the material can oxidize propane by reducing itself and producing CO2. The oxidant can be consumable in the oxidation reaction and can therefore be considered a scavenger. The oxidant can convert propane into propane oxide and water.

[0087] The material may include, contain, consist of, or consist essentially of one, one or more, or at least one composition or compound of formula (I):

[0088] Ru 1-x M x O2(I),

[0089] in:

[0090] x can be any number from about 0 to 0.1, inclusive,

[0091] M may be an element from period 4, 5 or 6 of the periodic table.

[0092] In formula (I), x can be any number from 0 to 0.1. x can be about 0, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.10 or a range including any two of the disclosed numbers. Non-limiting examples of the range can be about 0 - 0.1, 0.02 - 0.08, 0.03 - 0.07 or 0.04 - 0.06. x can be greater than 0 and less than or equal to 0.1, such that 0 < x ≤ 0.1. x can be greater than 0 and less than 0.1, such that 0 < x < 0.1.

[0093] In formula (I), M can be an element of the 4th period of the periodic table and can include K; an element of the 5th period of the periodic table and can include Rh, Ag or Ru; or an element of the 6th period of the periodic table and can include Pt or Ir. In formula (I), M can be from Group IA, Group IB or Group VIIIB. In formula (I), M can be an alkali metal, a noble metal, a coinage metal and / or a transition metal. In formula (I), M can be an element selected from Ag, K, Pt, Rh, Ir and Ru. In formula (I), M can be an element selected from Ag, K, Pt, Rh and Ir. In formula (I), M can be one of Ag, K, Pt, Rh, Ir and / or Ru. M can be Ag, K, Pt, Rh, Ir, or Ru.

[0094] Non-limiting examples of the oxide of formula (I) can include Ru 1-x Ag x O2, Ru 1-x K x O2, Ru 1-x Pt x O2, Ru 1- x Rh x O2, Ru 1-x Ir x O2, Ru 1-x Ru x O2, Ag 0.1 Ru 0.9 O2, K 0.1 Ru 0.9 O2, Ru 0.9 Pt 0.1 O2, Ir 0.1 Ru 0.9 O2 or Ru 0.9 Rh 0.1 O2.

[0095] The material can comprise, consist of, consist essentially of one, one or more, or at least one composition or compound of formula (II):

[0096] Co 3-x M x O4 (II),

[0097] wherein:

[0098] x can be any number from about 0 to 0.3, including 0.3,

[0099] M can be an element of the 4th or 5th period of the periodic table of elements.

[0100] In formula (II), x can be any number from 0 to 0.3. x can be about 0, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.10, 0.105, 0.11, 0.115, 0.12, 0.125, 0.13, 0.135, 0.14, 0.145, 0.15, 0.155, 0.16, 0.165, 0.17, 0.175, 0.18, 0.185, 0.19, 0.195, 0.20, 0.21, 0.215, 0.22, 0.225, 0.23, 0.235, 0.24, 0.245, 0.25, 0.255, 0.26, 0.265, 0.27, 0.275, 0.28, 0.285, 0.29, 0.295, 0.30, or a range including any two disclosed numbers. Non-limiting examples of ranges can be about 0 - 0.3, 0.01 - 0.29, 0.05 - 0.25 or 0.07 - 0.20. x can be greater than 0 and less than or equal to 0.3, such that 0 < x ≤ 0.3. x can be greater than 0 and less than 0.3, such that 0 < x < 0.3.

[0101] In formula (II), M can be an element of the 4th period of the periodic table of elements and can include Co, Ni or Cu; or an element of the 5th period of the periodic table of elements and can include Sr or Pd. In formula (II), M can be from Group IA, Group IB or Group VIIIB. In formula (II), M can be an alkaline earth metal, a noble metal, a transition metal and / or a metal from the iron group elements. In formula (II), M can be an element selected from Pd, Cu, Sr, Ni and Co. In formula (II), M can be an element selected from Pd, Cu, Sr or Ni. In formula (II), M can be one of Pd, Cu, Sr, Ni and / or Co. M can be Pd, Cu, Sr, Ni or Co.

[0102] Non-limiting examples of the oxide of formula (II) may include Co 3-x Pd x O4、Co 3-x Cu x O4、Co 3-x Sr x O4、Co 3- x NiO4、Co 3-x Co x O4、Co 2.7 Pd 0.3 O4、Co 2.7 Cu 0.3 O4、Sr 0.3 Co 2.7 O4、Co 2.8 Pd 0.2 O4、Co 2.8 Ni 0.2 O4、Co 2.8 Cu 0.2 O4、Sr 0.2 Co 2.8 O4.

[0103] The material may include, contain, consist of, or consist essentially of one, one or more, or at least one composition or compound of formula (III):

[0104] MM' x O y or M a M' x O y (III)

[0105] in:

[0106] a can be 1;

[0107] x can be any number from 0 to 1.5, inclusive;

[0108] y can be any number from 1 to 3, inclusive;

[0109] M may be an alkali metal;

[0110] M' may be an element from period 4, 5 or 6 of the periodic table.

[0111] In formula (III), a may be 1. In formula (III), a is 1.

[0112] In formula (III), x may be the stoichiometric ratio of M' to M. In formula (III), x may be any number from 0 to 1.5. x can be about 0, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.10, 0.105, 0.11, 0.115, 0.12, 0.125, 0.13, 0.135, 0.14, 0.145, 0.15, 0.155, 0.16, 0.165, 0.17, 0.175, 0.18, 0.185, 0.19, 0.195, 0.20, 0.21, 0.225, 0.235, 0.245, 0.250, 0.265, 0.275, 0.280, 0.290, 0.300, 0.315, 0.326, 0.330, 0.345, 0.350, 0.361, 0.375, 0.380, 0.390, 0.400, 0.410, 0.420, 0.430, 0.440, 0.450 2. 0.225, 0.23, 0.235, 0.24, 0.245, 0.25, 0.255, 0.26, 0.265, 0.27, 0.275, 0.28, 0.285, 0.29, 0.295, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60、0.61、0.62、0.63、0.64、0.65、0.66、0.67、0.68、0.69、0.70、0.71、0.72、0.73、0.74、0.75、0.76、0.77、0.78、0.79、0.80、0.81、0.82、0.83、0.84、0.85、0.86、0.87、0.88、0.89、0.90、0.91、0.92、0.93、0.94、0.95、0.96、0.97、0.98、0.99、1.00、1.01、1.02、1.03、1.04、1.05、1.06、 47, 1.48, 1.49, 1.50, or a range including any two of the disclosed numbers.Non-limiting examples of the range can be about 0 - 1.5, 0.01 - 1.4, 0.1 - 1.25 or 0.5 - 1.0.

[0113] x can be greater than or equal to 0 and less than or equal to 1.5 such that 0 ≤ x ≤ 1.5. x can be greater than 0 and less than or equal to 1.5 such that 0 < x ≤ 1.5. x can be greater than or equal to 0 and less than 1.5 such that 0 ≤ x < 1.5. x can be greater than 0 and less than 1.5 such that 0 < x < 1.5.

[0114] In formula (III), y may be a stoichiometric ratio of O to M. In formula (III), y may be any number from 1 to 3. x can be about 1.0, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.30, 1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.39, 1.40, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47、1.48、1.49、1.50、1.51、1.52、1.53、1.54、1.55、1.56、1.57、1.58、1.59、1.60、1.61、1.62、1.63、1.64、1.65、1.66、1.67、1.68、1.69、1.70、1.71、1.72、1.73、1.74、1.75、1.76、1.77、1.78、1.79、1.80、1.81、1.82、1.83、1.84、1.85、1.86、1.87、1.88、1.89、1.90、1.91、1.92、1.93、1.94 , 1.95, 1.96, 1.97, 1.98, 1.99, 2.00, 2.01, 2.02, 2.03, 2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.10, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, 2.20, 2.21, 2.22, 2.23, 2.24, 2.25, 2.26, 2.27, 2.28, 2.29, 2.30, 2.31, 2.32, 2.33, 2.34, 2.35, 2.36, 2.37, 2.38, 2.39, 2.40, 2.41, 2.4 2.2, 2.43, 2.44, 2.45, 2.46, 2.47, 2.48, 2.49, 2.50, 2.51, 2.52, 2.53, 2.54, 2.55, 2.56, 2.57, 2.58, 2.59, 2.60, 2.61, 2.62, 2.63, 2.64, 2.65, 2.66, 2.67, 2.68, 2.69, 2.70, 2.71, 2.72, 2.73, 2.74, 2.75, 2.76, 2.77, 2.78, 2.79, 2.80, 2.81, 2.82, 2.83, 2.84, 2.85, 2.86, 2.87, 2.88, 2.89, 2.90, 2.91, 2.92, 2.93, 2.94, 2.95, 2.96, 2.97, 2.98, 2.99, 3.00, or a range including any two disclosed numbers. Non-limiting examples of the range can be about 1.0 - 3.0, 1.1 - 2.8, 1.5 - 2.5, or 1.8 - 2.0.

[0115] y can be greater than or equal to 1 and less than or equal to 3, such that 1 ≤ y ≤ 3. y can be greater than 1 and less than or equal to 3, such that 1 < y ≤ 3. y can be greater than or equal to 1 and less than 3, such that 1 ≤ y < 3. x can be greater than 0 and less than 3, such that 1 < y < 3.

[0116] The total oxygen content (y / y + 1) can be from 0.5 to 0.75. The total oxygen content (y / y + 1) can be about 0.5 - 0.75, 0.55 - 0.72, or 0.58 - 0.70.

[0117] In formula (III), M can be an element of the 3rd period of the periodic table and can include K; or an element of the 4th period of the periodic table and can include K; an element of the 5th period of the periodic table and can include Rb; or an element of the 6th period of the periodic table and can include Cs. In formula (III), M can be from Group IA. In formula (III), M can be an alkali metal. In formula (III), M can be an element selected from Na, K, Rb, and Cs. In formula (III), M can be one of Na, K, Rb, or Cs. M can be Na, K, Rb, or Cs.

[0118] In formula (III), M' can be an element of the 4th period of the periodic table and can include Nb, Mn, or Cr; an element of the 5th period of the periodic table and can include Y, Rb, or Ag; or an element of the 6th period of the periodic table and can include Ta, La, Au, or Nd. In formula (III), M' can be from Group IB, IIIB, VB, VIB, or VIIB. In formula (III), M' can be a transition metal, noble metal, lanthanide element, and / or coinage metal. In formula (III), (if x > 0), M' can be an element selected from Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, and Cr. In formula (III), M' can be one of Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, or Cr. M can be Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, and / or Cr.

[0119] In formula (III), at least one or both of M and M' can be a metal.

[0120] Non-limiting examples of the oxide of formula (III) can include K a M’ xO y , K a Mn x O y , K a Nb x O y , K a Ta x O y 、Na a M' x O y , Rb a M' x O y , Rb a Mn x O y , Rb a Nd x O y , Rb a La x O y , NaO2, KO2, RbO2, CsO2, RbYO2, K2PtO6, Rb2CeO3, K3NbO8, K3TaO8, Rb3NbO8, Rb3Ta O8, Cs3TaO8, KMnO4, RbLaO2, RbNdO2, RbMnO4, CsMnO4, Na4(NiO2)9, KAgO2, NaAgO2.

[0121] In formula (III), due to the stoichiometric ratios x and y, the formula can be written in more than one form. For example, K2PtO6 can be rewritten as KPt 0.5 O3, which is within the scope of the nomenclature. Similarly, Rb3NbO8 can be rewritten as RbNb 0.33 O 2.67 Thus, in the non-limiting examples disclosed herein, where "a" is written as a formula with a value greater than 1, x and y can be divided by the value of "a" to obtain a formula in which "a" is represented as 1 and x and y are stoichiometric values. For example, K3NbO8 can also be written as KNb 0.33 O 2.67 , because x = 1 / 3 and y = 8 / 3.

[0122] In one or more embodiments, the material of formula (I) can be combined with the material of formula (II), (III), or both. In one or more embodiments, the propane gas utilization system as described herein can include one, at least one, or more than one composition of the material of formula (I), one, at least one, or more than one composition of the material of formula (II), and / or one, at least one, or more than one composition of the material of formula (III).

[0123] In a non-limiting example, the material may include at least one composition of formula (I) (which includes K 0.1 Ru 0.9 O2、Ag 0.1 Ru 0.9 O2 or both) and at least one composition of formula (II) (including Co 2.7 Cu 0.3 O4、Sr 0.3 Co 2.7 In addition, or alternatively, the material may comprise one or more compositions of formula (III) (which comprise NaO2, KO2, K3NbO8, K3TaO8, or a combination thereof). Furthermore, depending on the priorities of the application, such as cost, reactivity, and / or stability, the material may be tailored from compounds of formula (I), (II), and / or (III), for example as disclosed in Tables 3-9 in the Experimental section below.

[0124] In addition, the material may include at least one of a catalyst, a scavenger or an oxidant having a composition of formula (I), (II) or (III). The material may include a combination of a catalyst, a scavenger and / or an oxidant having a composition of formula (I), (II) and / or (III). The material may include only one or more compounds of formula (I), (II) and / or (III), which are arranged as a catalyst, which is configured to convert propane into one or more compounds having a density lower than that of propane. The material may include only one or more compounds of formula (I), (II) and / or (III), which are arranged as a scavenger, which is configured to convert into another compound comprising propane. The material may include only one or more compounds of formula (I), (II) and / or (III), which are arranged as a superoxidant, which is configured to oxidize propane by self-reduction and forming CO2.

[0125] The materials disclosed herein may be concentrated in components such as Figure 1A , 1B 20. The component 34 may be of any size, shape, and configuration to act as a catalyst, oxidant, or scavenger for any propane gas that may have the ability to escape from the propane gas utilization system 20. The component 34 may be located anywhere within the system 20, the cellar or basement 50, or both. The component 34 may be located at the bottom of the housing 22 so that propane that tends to sink to the ground due to its density will encounter the component 34, and the material will prevent the propane from accumulating in the system 20. The component 34 may include a layer or block that includes a composition of one or more materials of formula (I), (II), and / or (III).

[0126] Assembly 34 may be a removable and / or replaceable assembly containing the material. Thus, the material may be replaced, replenished and / or exchanged during periodic maintenance of the propane gas utilization system. This is particularly true for materials that are converted by reaction with propane during the scavenging reaction (the amount of which will decrease / be consumed over time).

[0127] The material may be provided as a coating 36, such as Figure 1C As shown. Coating 36 can have one or more layers. Each layer can have the same or different composition. For example, the first layer / top layer can contain a composition of one or more materials of formula (I), (II) and / or (III). The second layer can contain the same or different composition of materials of formula (I), (II) and / or (III). Additional layers are contemplated. Each additional layer of coating 36 can contain a composition of materials of formula (I), (II) and / or (III) that is the same or different from the first layer and / or second layer.

[0128] The coating 36 may be a coating on any portion / surface of the propane gas utilization system, heat pump system 20, including but not limited to the ventilation / exhaust duct 26, the surface of the shell 22, the refrigerant circuit 24 shell, the gas seal 30, (one or more) pipe sections, etc., or a combination thereof. The coating 36 may be disposed on the surface of the cellar or basement 50. The coating 36 may be limited to or applied only to any lower portion of the house / basement where propane gas is prone to accumulation.

[0129] The materials disclosed herein can be in the form of nanoparticles. The nanoparticles can have the same or different sizes, diameters, dimensions, orientations, structures, facet contents, compositions. The loads of the oxides of formula (I), (II), (III) or combinations thereof can be different or the same. It is expected that more than one layer comprising the oxides of formula (I), (II), (III) or combinations thereof can be formed. These layers can have the same or different structures, loads of various oxides, types of oxides, sizes of oxide nanoparticles, etc., or combinations thereof. The form of nanoparticles can increase the surface area, thereby increasing the reaction rate.

[0130] In non-limiting examples, the nanoparticles can have a size of about 10 nm to 1 μm (1000 nm), 50 nm to 0.75 μm (750 nm), or 100 nm to 0.5 μm (500 nm). The size of the nanoparticles can be about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 520, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, or 1000 nm.

[0131] The oxide material(s) may be deposited on a specified support material(s), including but not limited to carbon, metal, ceramic, CeO2, AlO x 、TiO x 、MnO x 、NbO x etc., or a combination thereof.

[0132] In addition to the example heat pump systems disclosed herein, the materials disclosed herein may also be used in any propane gas utilization system, such as another heat pump system, a propane storage tank, a propane heater, a chemical engineering process that produces propane as a byproduct, or another application containing propane gas.

[0133] The oxides disclosed herein can be prepared by conventional methods known to those skilled in the art. For example, the oxides can be deposited using solution processes; these processes may include involving hydrate or hydroxide precursors, and may include baking steps above about 50-100°C. The oxides can also be prepared using sputtering or plasma processes, or by high temperature sintering above about 400-600°C. The oxides can also be prepared as thin film coatings using atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0134] The propane gas utilization system can have two modes or states. The system can include a first state in which propane gas accumulates in the system. The system can be operated or shut down in the first state. The system can include a second state in which the disclosed material removes accumulating or accumulated propane from the system. The second state can include the disclosed material for catalyzing the accumulating or accumulated propane and returning it to its natural state, removing the accumulating or accumulated propane by converting it into a secondary material containing propane molecules, and / or oxidizing the propane. The system can be operated or shut down in the second state.

[0135] In one or more embodiments, a method of using a material of formula (I), (II) and / or (III) is disclosed. The method may include preparing a compound of one or more materials of formula (I), (II) and / or (III). The method may include adjusting the composition of the material based on a priority factor (e.g., reactivity or cost). The method may include forming the material into a permanent or temporary application within a propane gas utilization system. For example, the method may include arranging the material into one or more layers, a single layer coating, a multilayer coating, or an assembly. The method may include applying the material to one or more surfaces of a propane gas utilization system, such as a housing surface, a gas seal surface, a pipeline surface, etc. The method may include providing the material as a separate component and installing the component within the propane gas utilization system, such as near or on the ground surface within the system. The method may include regularly or randomly checking, replacing, reinstalling, removing, reapplying, or reinstalling the component, coating, and / or material within the system.

[0136] Experimental Section

[0137] The materials disclosed herein were identified using density functional theory (DFT), which solves the electron interaction system of the ground state energy of the material. There are multiple energy databases available. In order to identify the disclosed materials, the following steps were taken:

[0138] Calculate the total energy, which describes the calculated energy of the structure (usually in units of eV / atom or eV). The differences between the structures correspond to the reaction energies between those structures. For example, the reaction A→B has a reaction energy E B -E A (where energy can be written in kJ / mol).

[0139] The convex hull of all stable compositions is constructed like this: every chemical composition C has a minimal stable state combination, C→A+B, where the stoichiometry of C is equal to the sum of A and B, and there is no other A'+B' with lower energy. Then A+B represents the convex hull decomposition products of C. If the energy of C is known, the hull energy or decomposition energy (usually eV / atom or eV) is E h =E C -E A -E B and is always non-negative. In some conventions, it is reported as the reaction energy E rxn =E A +E B -E C And it is always a non-positive number.

[0140] Identify the chemical potential (usually in units of eV / atom or eV), which describes the stoichiometric imbalance of the elements in the reaction process. The chemical potential of oxygen or hydrogen is often used, corresponding to an oxidizing or reducing environment. Chemical potential can also be used as a proxy for temperature, as high temperatures may accelerate oxidation.

[0141] Explore various types of materials using information on total energy, convex hull decomposition, and chemical potential. These include any known material whose DFT structure can be calculated, typically single crystals or gas-phase molecules, and compositional formulas, even if the atomic structure is unknown, as long as there is a relevant structure in the database. This includes: adjusting compositional ratios, such as excess oxygen or oxygen vacancies, and / or dopants and substituents.

[0142] The following properties are calculated:

[0143] (A) Stability at a fixed temperature - this can be given by the packet energy; if this value is less than the temperature (times the Boltzmann constant k B ), then the material is stable. Alternatively, stability at a fixed temperature can be calculated from the oxygen chemical potential, which can be referenced to a known scale of temperature. Only the package energy is used.

[0144] (B) Filter by atomic size, oxidation state, metal-oxygen ratio, crystal structure, space group, element, etc.

[0145] (C) Cost of basic materials per mole or kilogram.

[0146] (D) Composition stability, defined as composition C having no decomposition products that are "red flag" products. It is not reasonable to set a standard of having no decomposition products because many materials with non-zero decomposition energies are commonly used. Instead, we evaluate the decomposition products based on reference materials. Figure 2 An algorithm for screening decomposition products is shown. The “red flag” product C i The total scores of are weighted summed and used as a measure of instability.

[0147] (E) Reactivity screening was performed, i.e., the probability of a reaction between a composition C and a reactant R. Using the convex hull method, the reactivity was calculated by examining (1) the decomposition products of the composition C+xR and (2) the relative decomposition energy ε(x) = E(C+xR)-E(C)-xE(R) (non-positive). The latter is Figures 3A-3C The most stable reaction is the one with the smallest ε, while the dilution limit is the lowest value of x with non-zero ε.

[0148] Using this approach, the reactivity can be benchmarked to some known material C' using the following two quantities:

[0149] (I) At what mole fraction x does the reaction occur? The higher the reactivity, the higher the value of x, i.e. more reactions occur per mole unit C (or C'). A typical measure is: RR stoich =x C / x C’ , where C' is the reference material and RR stands for relative reactivity.

[0150] (II) What is the relative decomposition energy ε? The higher the reactivity, the lower the ε value (the higher the absolute value), i.e. the more energetically favorable the reaction. The typical metric here is: RR en =ε C / ε C’ , where C' is the reference material. It can also be: RR en =(ε C′ -ε C ) / k B T, where k B is the Boltzmann constant and T is the absolute temperature. Use the latter where T is room temperature.

[0151] Table 3 below lists non-limiting examples of chemical reactivity, reactions, stoichiometric fractions, and relative decomposition energies for various materials.

[0152] Table 3 - Chemical reactivity, reactions, stoichiometric fractions and relative decomposition energies of various materials

[0153]

[0154] The various oxide materials were screened according to the following criteria:

[0155] (I) For search spaces A and B, the stability metrics described above are used, respectively, where the reference materials are RuO2 and Co3O4;

[0156] (II) reactivity with O2, H2O and CO2, where the enthalpy and stoichiometric RR for the most stable reaction give a score of -0.25 (negative) for each reactant, as described above;

[0157] (III) reactivity with C3H3, where the enthalpy and stoichiometry RR for the most stable reaction give a positive ("good") score, as described above; and

[0158] (IV) Cost per kilogram (basic material cost).

[0159] Under (I), search space A: Since RuO2 is a known catalyst material, a search was conducted for a Ru-based material in which at least a portion of the Ru could be replaced. The goal was to have at least 10% Ru substitution, so the search focused on identifying Ru 0.9 M 0.1M in O2, where M is a non-radioactive element and / or metal. The reference material is RuO2. The search revealed 59 materials / compounds.

[0160] Search space B: Since Co3O4 is a known catalyst material and can be doped with Ni, we searched for Co 3-x M x O4, where x is 0.2 or 0.3 and M is a non-radioactive element and / or metal. The reference material is Co3O4. The search revealed 117 materials / compounds.

[0161] Search space C: binary and ternary oxides A 1-x B x O y A search was performed with the following restrictions. These materials tend to be scavenging materials. The reference material is Co3O4, but no stability analysis was performed because these materials are very different from the reference material. The restrictions on the search space C are as follows:

[0162] i. The package energy is less than 25meV (300K);

[0163] ii. A and B are not radioactive and are not the following rare, reactive or unwanted elements: F, Cl, Be, Pb, Hg, He, H, Li, P, S, As, Se, Br, Cd, I, Sb, Te, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu;

[0164] iii. y is from 1 to 3, or the total oxygen content (y / y+1) is from 0.5 to 0.75; and

[0165] iv. At least one of A and B must be a metal.

[0166] Under (II), the reactivity screen was evaluated. Figures 4A-4I Several examples of interface reaction energy diagrams are shown. Table 4 below further shows several examples of chemical reactivity, reactions, stoichiometric fractions, and relative decomposition energies.

[0167] Table 4 - Non-limiting examples of chemical reactivity, reactions, stoichiometric fractions, and relative decomposition energies for materials identified in search spaces AC

[0168]

[0169]

[0170] Tables 6, 7 and 9 and Appendix Figure 6-8 The "weighted reactivity" measure in the plot of is given by the weighted sum of the following values, all for the "most stable" reaction (the minimum in the interfacial reactivity plot):

[0171] 4x RR stoich For C3H8

[0172] 4x RR en For C3H8

[0173] -1x RR stoich For each of O2, CO2 and H2O

[0174] -1x RR en For each of O2, CO2 and H2O

[0175] Under (III), stability screening was evaluated. Table 5 lists and Figure 5 The stability of several example materials is shown. The weight fractions of unstable materials are summed and used as a measure of stability.

[0176] Table 5 - Stability analysis results for non-limiting examples of materials identified in search spaces AC

[0177]

[0178] Under (IV), Table 6 and Figure 6 The cost evaluation is summarized along with the overall evaluation of the materials identified in search space A. The listed materials are at least 80 wt% stable (unstable weight fraction < 0.2) and have better weighted reactivity than RuO2 (reference material) (reacts with C3H8 but not with other reactants as described above).

[0179] Table 6 - Evaluation of non-limiting examples of compounds in search space A relative to reference materials

[0180]

[0181]

[0182] Under (IV), the following Table 7 and Figure 7 The cost evaluation and overall assessment of the materials identified in search space B are summarized in . The following materials are at least 90 wt% stable (unstable weight fraction < 0.1) and have better weighted reactivity (reacts with C3H8 but not with other reactants as defined above) than Co3O4 (reference material). Ni was used to validate the approach.

[0183] Table 7 - Evaluation of non-limiting examples of compounds in search space B relative to reference materials

[0184] Material Weighted Reactivity Unstable weight fraction Cost per kg <![CDATA[Co 2.7 Pd 0.3 O4]]> 1.281 0.056 2906.888 <![CDATA[Co 2.7 With 0.3 O4]]> 1.065 0.000 25.209 <![CDATA[Sr 0.3 What 2.7 O4]]> 1.031 0.000 23.917 <![CDATA[Co 2.8 Pd 0.2 O4]]> 0.948 0.037 1983.446 <![CDATA[Co 2.8 In 0.2 O4]]> 0.797 0.100 26.650 <![CDATA[Co 2.8 With 0.2 O4]]> 0.786 0.000 25.902 <![CDATA[Sr 0.2 What 2.8 O4]]> 0.770 0.000 25.017 <![CDATA[Co3O4 (Reference material)]]> 0.250 0.000 27.295

[0185] In search space C, over 3000 materials were screened. Trends were sought among the best candidates to identify a class of materials that could be used for catalyst / scavenger / strong oxidant purposes. Several of the best candidates identified were a group of basic oxides that can form metal carbonates and act as scavenger materials. These oxides generally have a set of reactions similar to the following, where the carbonation of the alkali metals has a high enthalpy.

[0186] Surprisingly, it has been found that alkali metals can be used in propane gas scavenging reactions, while readily forming carbonates with propane, but with less preference with carbon dioxide. Tables 8 and 9 and Figure 8 Example materials are shown.

[0187] Table 8 - Evaluation of non-limiting examples of compounds in search space C

[0188]

[0189] Table 9 - Evaluation of non-limiting examples of compounds in search space C

[0190]

[0191]

[0192] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The words used in the specification are descriptive rather than restrictive words, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. As previously mentioned, the features of various embodiments can be combined to form further embodiments of the present invention that may not be clearly described or illustrated. Although various embodiments may be described as providing advantages or being superior to other embodiments or prior art embodiments in terms of one or more desired characteristics, it is recognized by those of ordinary skill in the art that one or more features or characteristics can be sacrificed to achieve the desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cost, marketability, appearance, packaging, size, applicability, weight, manufacturability, ease of assembly, etc. Therefore, if any embodiment is described as not as ideal as other embodiments or prior art embodiments in terms of one or more characteristics, then these embodiments do not exceed the scope of the present disclosure and may be ideal for specific applications.

Claims

1. A propane gas utilization system, comprising: A housing containing propane gas; An anti-propane leakage material, which contains a catalyst, a scavenger, and / or an oxidant for the propane gas disposed in the housing, and contains at least one of the following (a) An oxide material having a composition of at least one of formula (I): Ru 1-x M x O2(I), Where: 0 < x ≤ 0.1, and M is Ag, K, Pt, Rh, or Ir, Or (b) An oxide material having a composition of at least one of formula (II): Co 3-x M x O4(II), Where: 0 < x ≤ 0.3, and M is Pd, Cu, or Sr, Or (c) An oxide material having a composition of at least one of formula (III): MM’ x O y (III), Where: x is the stoichiometric ratio of M' to M, 0 ≤ x ≤ 1.5, y is the stoichiometric ratio of O to M, 1 ≤ y ≤ 3, M is an alkali metal, and M' (if x > 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, or Cr.

2. The system according to claim 1, wherein the material is configured as a coating on at least one surface of the housing.

3. The system according to claim 1, wherein the material is a scavenger containing at least one oxide of formula (II) or (III).

4. The system according to claim 1, wherein the material forms a multi-layer coating, and each layer has the same composition.

5. The system according to claim 1, wherein the material contains basic oxides.

6. The system according to claim 1, wherein M in formula (I) or (III) is K.

7. The system according to claim 1, wherein the material is configured as a replaceable component of the propane gas utilization system.

8. The system according to claim 1, wherein the material contains at least one compound of formula (III), wherein M' is a transition metal and M is Na, K, Rb, or Cs.

9. A propane gas catalyst, comprising: At least one of the following (a) An oxide material having a composition of at least one of formula (I): Ru 1-x M x O2(I), Where: 0 < x ≤ 0.1, and M is Ag, K, Pt, Rh, or Ir, Or (b) An oxide material having a composition of at least one of formula (II): Co 3-x M x O4(II), Where: 0 < x ≤ 0.3, and M is Pd, Cu, or Sr, Or (c) An oxide material having a composition of at least one of formula (III): MM’ x O y (III), Where: x is the stoichiometric ratio of M' to M, 0 ≤ x ≤ 1.5, y is the stoichiometric ratio of O to M, 1 ≤ y ≤ 3, M is Na, K, Rb, or Cs, and M' (if x > 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, or Cr, The catalyst is configured to increase the rate of propane gas oxidation without being consumed in the reaction.

10. The catalyst according to claim 9, wherein the catalyst is a propane gas catalyst for a heat pump system.

11. The catalyst according to claim 9, wherein the catalyst forms a nano-particle layer.

12. The catalyst according to claim 9, wherein the catalyst only contains oxides of formula (I).

13. The catalyst according to claim 9, wherein the catalyst is disposed as a multi-layer coating.

14. The catalyst according to claim 13, wherein each layer of the multilayer coating comprises one or more compounds of the same formula (I), (II) or (III).

15. A propane gas scavenger, comprising: at least one of the following (a) an oxide material having a composition of at least one formula (I): Ru 1-x M x O2(I), wherein: 0 < x ≤ 0.1, and M is Ag, K, Pt, Rh or Ir, or (b) an oxide material having a composition of at least one formula (II): Co 3-x M x O4(II), wherein: 0 < x ≤ 0.3, and M is Pd, Cu or Sr, or (c) an oxide material having a composition of at least one formula (III): M a m' x O y (III), wherein: x is the stoichiometric ratio of M' to M, 0 ≤ x ≤ 1.5, y is the stoichiometric ratio of O to M, 1 ≤ y ≤ 3, M is an alkali metal, and M' (if x > 0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au or Cr, the scavenger is configured to selectively react with propane gas to convert the propane gas into a composition having a density lower than that of the propane gas.

16. The scavenger according to claim 15, wherein the scavenger is a propane gas scavenger for a heat pump system.

17. The scavenger according to claim 16, wherein the scavenger is a replaceable component of a heat pump system.

18. The scavenger according to claim 15, wherein the scavenger forms a nanometer particle layer.

19. The scavenger according to claim 15, wherein the scavenger comprises at least one compound of formula (III), wherein M' is a transition metal.

20. The scavenger according to claim 15, wherein the scavenger comprises a mixture of compounds of formula (II) and (III).

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