Electro-catalytic treatment of fluids and related materials and coatings therefor

Abstract

A coating and material design are disclosed. The coating includes an alloy of nickel and molybdenum, or an oxidic compound of nickel and molybdenum, or a composite or metal matrix composite of the oxidic compound in the alloy. The alloy is selected from high molybdenum alloys, where Nickel is the balance of the elemental analysis. The oxidic compound is selected from oxides, hydrates or hydrolysed oxides of nickel and oxides, hydrates or hydrolysed oxides of molybdenum. The composite or metal matrix composite includes the oxidic compound embedded in or bonded by a metallic matrix of the alloy. The material design has a solid surface in a system for electro-catalytic treatment of a fluid under turbulent flow conditions of the fluid to be treated, the material design comprising the alloy, or the oxidic compound, or the composite or metal matrix composite described above.

Description

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 548,652, titled “ELECTRO-CATALYTIC TREATMENT OF FLUIDS AND RELATED MATERIALS AND COATINGS THEREFOR” and filed on Feb. 1, 2024, the contents of which are incorporated herein by reference.

[0002] In various aspects, this invention relates generally to material-based improvements of the electro-catalytic efficiency of devices treating various types of fluids (liquids or gases), fluid mixtures, and liquid solutions including water in order to modify their functional profile or purify these or to eliminate bacteria and micro-organisms. The liquids include monophasic and multiphasic fluids, emulsions and / or loaded with particles, either as fresh or waste / used fluids.

[0003] According to the EC commission, an emulsion is “Any stable mixture of two liquids that naturally do not mix together or dissolve in each other (such as oil and water), where one liquid (in the form of fine droplets or globules) is dispersed in the other.” ASTM D4175 defined it as a suspension of fine particles or globules, or both, of one or more liquids in another liquid. DIN51835 defined an emulsifiable cooling lubricant (SCEM), water-miscible cooling lubricant that forms an oil-in-water emulsion, when mixed with water. Note that oil is usually understood to be a liquid phase that is not miscible with water. Emulsion or Emulsifying—Emulsions are “disperse systems of two or more immiscible liquids.”

[0004] In various aspects, this invention relates to a coating that may be applied to intermediate materials or structures (e.g., tube, pipe, sheet) or products (e.g., a pump casing) or finished products (e.g., a device or structure that operates with a fluid).

[0005] A need exists to further increase the catalytical efficiency of the system and method for an electro-catalytic treatment of fluids under turbulent flow conditions as described by WO 2021 / 108888 and WO 2021 / 217270.

[0006] Useful materials and coatings, and applications thereof, have been identified.BACKGROUND

[0007] WO 2021 / 108888 A1 (US 2022 / 410089 A1) discloses a reversing flow apparatus, system and method, which effectively converts the flow of a liquid from laminar to a turbulent flow by rings mounted on a shaft comprising a circumference and one or more S-shaped members extending from a point in the circumference to another point in the circumference and across a center of the ring. These rings may be manufactured in stainless steel 300 series (for example 316L and 317L) or stainless steel 904L, preferably stainless steels containing Molybdenum. The disc-like elements are made of a corrosion resistant and monolithic metal or alloy containing from about 0.5 wt.-% to about 5 wt.-% molybdenum in non-magnetic stainless steel alloys. These alloys are not claimed for the shaft / central rod (#180) or tube (#110).

[0008] The functional surfaces are mechanically processed or polished to remove any scale and surface contamination from the production process.

[0009] WO 2021 / 217270 A1 (US 2023 / 183097 A1) discloses a system and method, which effectively produces a cooled turbulent flow in a source of liquid material. A series of sequential disk-like elements generates cavitation zones and shear planes within the housing. These disk-like elements may be realized S-shaped or in a scallop design. The disc-like elements may be made from a stainless steel 300 series or 900 series alloy such as 316 or 316L; 317 or 317L; or 904 or 904L. The claimed metal alloys of the disc-like elements consist of 0.5-40 wt.-% molybdenum and 5-25 wt.-% Nickel. Apart from 300 and 900 series alloys as well as claiming Nickel and Molybdenum as main alloying elements, no other alloying elements needed for catalytical treatment were disclosed.

[0010] These alloys as well as Nickel and Molybdenum alloying are not claimed for the shaft / central tube (#180) or tube / housing (#110).

[0011] The surface finishing of the disc-like elements is limited to “machined or polished with a non-ionic sanding grit which contains no metal contaminants.”. The disclosed surface finish is a No. 4 finish produced by mechanical polishing. ASTM A480 defines no. 4 finish as “a linearly textured finish that may be produced by either mechanical polishing or rolling. Average surface roughness (Ra) may generally be up to 25 micro-inches (0.64 micro-meters).” It is in the nature of polishing that the inner surface area of a mechanical surface is reduced, which in turn should be large as possible for catalytic reactions, e.g. the points for adsorption of substances per surface area.

[0012] WO 2021 / 217270 (US 2023 / 183097) discloses polyvinyl chloride (PVC) as substantially inert material for the tubular housing of the disk-like elements. In order to enhance the efficiency of the system by increasing the catalytically active surface area, the tubular housings and the shaft / central rod are also made either in stainless steels of 300- and 900-series alloys or in alloys as shown in Table 1 or coated with the disclosed oxides, hydrated or hydrolysed oxides or hybrids.TECHNICAL PROBLEMS

[0013] Devices as per WO 2021 / 108888 and WO 2021 / 217270 have shown in many different applications, that the claimed results were achieved. It is a consequence of the subject matter of the invention, that the intentional generation of the turbulent flows between the disks impedes the flowing velocity through the device and thus limits the treatment performance per fluid volume, because the “disk” represent “flow barriers”, slow down the flow and effects total costs of ownership. The swirling fluids remain between the disks for a certain time and pass the catalytically active surfaces several times. In general, it is desirable to increase the flow rate without sacrificing treatment efficiency. The performance of a treating component can be increased, if the number of catalytically active centers on the surfaces is greatly increased. This increases the admissible volume flow rate of the device and thus lowers the total costs of ownership.

[0014] The number of catalytically active centers per surfaces area can be increased and improved by:

[0015] a. Increasing the concentration of Nickel and Molybdenum over WO 2021 / 108888 and WO 2021 / 217270 as well as reducing the non-catalytically active alloying element iron, and / or

[0016] b. Increasing the surface roughness and / or its surficial porosity, and / or

[0017] c. Growing of octahedral grain and plate-like grain type layers or coatings, and / or

[0018] d. Deposition of porous coatings, e.g. thermal spraying techniques.SUMMARY

[0019] In accordance with an aspect of an embodiment, there is proved a coating including: i) an alloy of nickel and molybdenum, or ii) an oxidic compound of nickel and molybdenum, or iii) a composite or metal matrix composite of ii) in i). The alloy of nickel and molybdenum is selected from high molybdenum alloys between 12-50 wt.-% molybdenum and iron contents below 10 wt.-% iron, where Nickel is the balance of the elemental analysis with at least 49 wt.-% Nickel. The oxidic compound of nickel and molybdenum is selected from oxides, hydrates or hydrolysed oxides of nickel (NiO, Ni2O5, β-NiOOH, γ-NiOOH, Ni(OH)2, Ni(OH)3) and oxides, hydrates or hydrolysed oxides of molybdenum (MoO2, MoO3, Magnéli-typeError! Bookmark not defined. phases of MoO3), Mo3O8xH2O (ilsemannite), e.g. Mo4+Mo6+2O8·nH2O, MoO3·nH20 with n=⅓, ½, 1 or 2, MoO2.5(OH)0.5 or their double oxides (α- / β-NiMoO4, NiMoO4n·H2O). The composite or metal matrix composite includes an oxidic compound from the oxidic compound of nickel and molybdenum embedded in or bonded by a metallic matrix of the alloy of nickel and molybdenum.

[0020] In accordance with another aspect of an embodiment, there is provided a material design with a solid surface in a system for electro-catalytic treatment of a fluid under turbulent flow conditions of the fluid to be treated, including i) an alloy of nickel and molybdenum, or ii) an oxidic compound of nickel and molybdenum, or iii) a composite or metal matrix composite of ii) in i). The alloy of nickel and molybdenum is selected from high molybdenum alloys between 12-50 wt.-% molybdenum and iron contents below 10 wt.-% iron, where Nickel is the balance of the elemental analysis with at least 49 wt.-% Nickel. The oxidic compound of nickel and molybdenum is selected from oxides, hydrates or hydrolysed oxides of nickel (NiO, Ni2O5, β-NiOOH, γ-NiOOH, Ni(OH)2, Ni(OH)3) and oxides, hydrates or hydrolysed oxides of molybdenum (MoO2, MoO3, Magnéli-typeError! Bookmark not defined. phases of MoO3), Mo3O8xH2O (ilsemannite), e.g. Mo4+Mo6+2O8·nH2O, MoO3·nH20 with n=⅓, ½, 1 or 2, MoO2.5(OH)0.5 or their double oxides (α- / β-NiMoO4, NiMoO4n·H2O). The composite or metal matrix composite includes an oxidic compound from the oxidic compound of nickel and molybdenum embedded in or bonded by a metallic matrix of the alloy of nickel and molybdenum.

[0021] The alloy may be deposited by electroplating, a galvanic process, or thermal spraying. The surface may be roughened to Ra of 3-4 μm and above. The surface may be is pre-oxidized.

[0022] The substrate may be selected from any alloys sufficiently resistant to corrosion in respect to the application.

[0023] The alloy may be casted. The alloy may be sintered with either an open or closed porosity.

[0024] The oxidic compound may be composed of individual composition of the oxides, hydrates or hydrolysed oxides of nickel and molybdenum including their doubles.

[0025] The oxidic compound may be deposited by thermal or cold gas spraying. The oxidic compound may be a sintered body with either on open or closed porosity. 10-90 vol. % of the oxidic compound may be embedded in or bonded by the metallic matrix and form a composite or metal matrix composite or hybrid material.

[0026] The composite or metal matrix composite or hybrid material may be a sintered body with either an open or closed porosity. The composite or metal matrix composite or hybrid material may be deposited by thermal or cold gas spraying.

[0027] An object, such as farm equipment, may be coated with the coating described above.DETAILED DESCRIPTION

[0028] It is an object of this invention to improve the catalytic efficiency of the prior art. It is an object of the present invention to execute surfaces in contact with the fluids in high molybdenum alloys and high nickel-molybdenum alloys in order to allow a significantly increased flow rate through the tubular system, because the catalytical efficiency is increased, and catalytically active compounds can be applied in form of monolithic alloys or as platings on corrosion resistant alloys (substrates). Provided are improvements to the catalytical efficiency of the system. They include the following steps:

[0029] a.) The shaft / rod, inner surface of the tube (housing) and surfaces of the disc-like elements are roughened in order to increase the catalytically active surface area.

[0030] b.) Pre-oxidation by static oxidation in air or by an oxygen plasma generates the catalytically active oxidic compounds on the surfaces prior to utilization.

[0031] c.) Electroplating of coatings based on Nickel and Molybdenum or containing these elements at elevated contents.

[0032] d.) Thermal spraying of oxidic compound and compounds of mixed oxides of Nickel and / or Molybdenum, e.g. NiMoO4.

[0033] e.) Disk elements sintered with metal powders containing high amounts of Nickel and Molybdenum or of oxidic compounds (e.g. NiO, MoO2, MoO3) and compounds of mixed oxides of Nickel and / or Molybdenum.

[0034] It is another object of this invention to provide one or more of the above benefits to structures and devices in general. This may be achieved by way of a coating, as will be discussed in detail below, that may be applied to intermediate materials or structures, intermediate products, or finished products.EXEMPLARY EMBODIMENTS

[0035] The present electro-catalytic concept under turbulent flow can be applied to a wide range of fluids and pollutants as well as for targeted functional modifications of fluids. The specific catalytic selectivities of Nickel and Molybdenum as well as their oxides and mixed oxides can be individually adapted to the application by adjusting the composition in the alloy or coating. Consequently, different ratios of nickel and molybdenum metal as well as NiO, MoO2, MoO3, NiMoO4 or Magnéli-type phases of MonO3n-1 can be chosen. These substances are chemically described and commercially available as powders of different granulometries.

[0036] Prof. Dr. Arne Magnéli recognized first at end of the 1930s, that oxides of molybdenum form homologous series with planar faults according to the common principles of MonO3n-1. “n” (n=4-10) is the plane spacing (distance) between the crystallographic shear (CS) planes These “grotesque” stoichiometries are sequences of ordered structures as homologous series of planar defect of the oxygen lattice, where oxygen layers are missing and are called CS planes. These types of thermally stable sub-oxides with planar oxygen defects are electrically conductive, because the valence of the metal atom adjunct to oxygen deficient plane changes. MonO3n-1 have a valence distribution (e.g. Mo5O14═Mo6+3Mo5+2) as consequences of the electrical conductivity in the CS plane.High Nickel and Molybdenum Alloys

[0037] Not all alloys represented in Table 1 containing Nickel and Molybdenum were part of 300 and 900 series alloys as disclosed by WO 2021 / 108888 (US 2022 / 410089) and WO 2021 / 217270 (US 2023 / 183097). These documents cover:

[0038] a. WO 2021 / 108888: stainless-steel containing molybdenum (Mo) in the range from 0.5 wt.-% to 4.0 wt.-% molybdenum as non-magnetic steels or in a metallurgical under-standing as austenitic steels and

[0039] b. WO 2021 / 217270: corrosion-resistant alloys containing molybdenum or stainless steel containing combinations of 0.5-40 wt.-% molybdenum and 5-25 wt.-% Nickel.

[0040] Both documents preconize and claim specifically 316L stainless steel, 317L stainless steel or 904L stainless steel. The claimed 300- and 900-series alloys are a too wide claim, because within these only 316L, 317L and 904L contain molybdenum. The specific alloys claimed by WO 2021 / 108888 and WO 2021 / 217270 contain also 16-23 wt.-% of chromium and iron as balance between <49-63 wt.-% iron (Table 1).

[0041] Irrespective of the maximum claimed sum of nickel (<25%) and of molybdenum (<40%) totaling to <65 wt.-% NiMo in WO 2021 / 217270, only 904L reaches max. 33 wt.-% NiMo or 316L max. 17 wt.-% of NiMo.

[0042] As visible from Table 1, the upper limit of 28 wt.-% nickel in 904L, as specified, lies outside of the range of the <25 wt.-% nickel claimed by WO 2021 / 217270.

[0043] There is a mismatch between the up to 4.0 wt.-% molybdenum claimed by WO 2021 / 108888 and that 904L is specified with 4-5 wt.-% molybdenum.

[0044] If around 17 wt.-% of chromium is added, 8 wt.-% of nickel is sufficient to obtain a stable “austenitic” microstructure. This is the case for the claimed 316L, 317L and 904L.

[0045] Duplex steels (3.5-8 wt.-% Ni, 0-5 wt. % Mo) are not covered by WO 2021 / 108888, because their concentrations of nickel are too low to fully stabilize the claimed “non-magnetic steels” (austenite). Duplex steels have a mixed microstructure of about 30-70% of austenite and ferrite phases. The austenite (γ) provides ductility and toughness and the ferrite (α) provides strength to be superior to that of fully austenitic steels. https: / / www.imoa.info / download_files / stainless-steel / Duplex_Stainless_Steel_3rd_Edition.pdf

[0046] The balance in the claimed AISI 316,317 or 904 alloys range between 38-62 wt.-% iron. It was found that the enrichment of iron oxides in the passive films or oxidative films / scales on these alloys reduces the catalytical efficiency and guides to the necessity to reduce the concentration of iron in alloys.

[0047] Further improvements in catalytic efficiency over WO 2021 / 108888 and WO 2021 / 217270 were found by using high molybdenum alloys between 12-30 wt.-% molybdenum and essentially low iron contents below 10 wt.-%, where mainly 53.1-59.2 wt.-% of Nickel is the balance of the elemental analysis (Table 1).

[0048] This balance in Nickel is much higher than the <25 wt.-% nickel claimed by WO 2021 / 217270. In the case of “High molybdenum alloys” as represented in Table 1, nickel balances range between ˜53-65 wt.-% nickel. In consequences, the “High molybdenum alloys” in Table 1 are not covered by the NiMo criteria as per WO 2021 / 217270. The newly claimed low iron content make an additional distinction. The iron content in the “High molybdenum alloys” is very low in order to enable high NiMo content for an improvement of the catalytical activity / efficiency.

[0049] The maximum efficiency was achieved additionally with master alloys (MO, MO1916 or Neirolium 130, C—NiMo31 (NC0012)) composed of nickel and molybdenum. Neirolium 130 is composed of 27 wt.-% Mo, bal. nickel. The ratio between nickel and molybdenum needs to be specifically adopted to the fluid of the application. Nickel and molybdenum range each between 10 wt.-% to 90 wt.-%. Such master alloys contains less than 5 wt.-% of other alloying elements.TABLE 1Denominations and elemental compositions of standardized alloys with molybdenumENComposition [wt. %]AlloyNo.UNS No.NiCuMoCrFeWMnAustenitic Stainless Steels316L (Fe bal. <62.5%)1.4404S3160310-14—2-316-18Bal.—<2317L (Fe bal. <58.5%)1.4438S3170311-15—3-418-20Bal.—<2904L (Fe bal. <39.0%)1.4539N0890423-281-24-519-23Bal.—<2Super Duplex alloysSuper Duplex Cr25*1.4410S327506-8<0.53-524-26Bal.—<1.2High molybdenum alloys#Hasteloy C-222.4602N06022Bal.—12.5-14.5  20-22.5—<0.35<0.5Nicrofer 5923 hMo2.4605N06059Bal.−0.515-1622-24<1.5—−0.5Hastelloy C2762.4819N10276Bal.—15-1714.5-16.54-7—<1Hastelloy C (CW-—N30002Bal.—16-1815.5-17.54.5-7.5—<112M)VDM 2120 MoN2.4700N06058Bal.—18.5-21  20-23<1.5—<0.5Hastelloy BC-12.4708N10362Bal.—2215<2<0.3<0.25Hastelloy B-22.4617N10665Bal.<0.526-30<1<2<0.5<1Haynes 242N10242Bal.<0.524-267-9<2—<0.8Haynes 244—Bal.22.58<26<0.8Hastelloy B-3 ®2.4600N10675>65<0.228.51.51.5<3<3N-7M (G-NiMo28)~2.4685N30007Bal.—31.5<1<3—<1N-12MV (G-~2.4882N30012Bal.—26-30<14-6—<1NiMo30)N-3MJ30003Bal.—30-33<1<3—<1MO1916——47-51—47-51—<0.5——Stainless steels with special additionsX1NiCrMoCuN25-1.4529N0892525-260.5-1.56-719-21Bal.—<120-7X1CrNiMoCuN25-1.453724-271-24.7-5.724-26Bal.—<225-5X1CrNiMoCuN20-1.4547S3125417.5-18.50.5-1  6-719.5-20.5Bal.—<118-7X1NiCrMoCu31-27-41.4563N0802830-32—3-426-28Bal.—<2X2CrNiMnMoN25-1.4565S3456516-19—4-524-26Bal.—5-718-6-5X2NiCrMoN25-21-71.4478N0836723.5-25.5<0.756-720-22Bal—<2Chemically resistant and high temperature resistant Ni alloysNiCr22Mo9Nb#2.4856N06625Bal. 8-1020-23<5<0.5X1CrNiMoCuN24-1.4652S3654221-230.3-0.67-823-25Bal.—2-422-8X1CrNiMoCuNW24-1.4659S3126621-231-25.5-6.523-25Bal.1.5-2.52-422-6*Alloy 2507, X2CrNiMoN25-7-4; UNS = Unified Numbering System;#Bal. Nickel: 53.1-59.2 (65) wt.-% Ni.TABLE 1(Cont): Denominations and elemental compositions of standardized alloys with molybdenumComposition [wt. %]AlloyEN No.UNS No.SiCAlTiOtherAustenitic Stainless Steels316L (Fe bal. <62.5%)1.4404S31603<0.75<0.03——317L (Fe bal. <58.5%)1.4438S31703<0.75<0.03——N: <0.1904L (Fe bal. <39.0%)1.4539N08904<1<0.02——N: <0.1Super Duplex alloysSuper Duplex Cr25*1.4410S32750<0.8<0.03——N: 0.24-0.32High molybdenum alloys#Hasteloy C-222.4602N06022<0.08<0.015——V: <0.35. Co: <2.5,Nicrofer 5923 hMo2.4605N06059<0.1<0.01<0.4—Co: <0.3Hastelloy C2762.4819N10276<0.08<0.01——<0.35 V, <2.5 CoHastelloy C (CW-12M)—N30002<1<0.12——V: 0.20.4,W: 3.75-5.25VDM 2120 MoN2.4700N06058<0.08<0.01<0.4—0.2-0.15 N, <0.3CoHastelloy BC-12.4708N10362<0.1<0.01<0.5—Co: <0.1,Hastelloy B-22.4617N10665<0.1<0.02——Co: <1Haynes 242N10242<0.8<0.03−0.5—B: <0.006, Co: <1,Haynes 244—<0.03<0.5—Hastelloy B-3 ®2.4600N10675<0.1<0.01<0.5<0.2—N-7M (G-NiMo28)~2.4685N30007<1<0.07———N-12MV (G-NiMo30)~2.4882N30012<1<0.12——V: 0.2-0.6N-3MJ30003<0.5<0.12——MO1916——<2.2———<0.015 NStainless steels with special additionsX1NiCrMoCuN25-20-71.4529N08925<0.5<0.02——N: 0.15-0.25X1CrNiMoCuN25-25-51.4537<0.7<0.02——N: 0.17-0.25X1CrNiMoCuN20-18-71.4547S31254<0.7<0.02——N: 0.18-0.25X1NiCrMoCu31-27-41.4563N08028<0.7<0.02——N: <0.11X2CrNiMnMoN25-18-1.4565S34565<1<0.03——Nb: <0.15;6-5N: 0.3-0.6X2NiCrMoN25-21-71.4478N08367<1<0.03——N: 0.18-0.25Chemically resistant and high temperature resistant Ni alloysNiCr22Mo9Nb#2.4856N06625<0.5<0.1<0.4<0.4Nb: 3.15-4.15,X1CrNiMoCuN24-22-81.4652S36542<0.5<0.02Cu: 0.3-06,N: 0.45-0.55X1CrNiMoCuNW24-1.4659S31266<0.7<0.02N: 0.35-0.5022-6*Alloy 2507, X2CrNiMoN25-7-4; UNS = Unified Numbering System;#Bal. Nickel: 53.1-59.2 (65) wt.-% Ni.The alloys in Table 1 or “high nickel and molybdenum alloys” can also be manufactured by means of sintering of metallic powders.

[0051] ISO 20507, item 2.2.58 described sintering as a process of densification and consolidation of a green body by the application of heat with resulting joining of ceramic particles and increasing contact interfaces due to atom movement within and between the ceramic grains of the developing polycrystalline microstructure. Sintering may take place either directly or through the agency of a secondary phase, e.g. in reaction sintering and liquid-phase sintering.

[0052] Sintering offers the advantages of near net shape forming and to realize a controllable open or closed porosity, which increases the catalytically active surface area. This represents a favored production method, because near net shape articles meet the tolerances of the parts used in an “electro-catalytic treatment of liquids under turbulent flow conditions”.

[0053] Table 2 in ISO 12725-2019 discloses nickel and nickel alloy castings with molybdenum concentration between 8-33 wt.-% molybdenum and iron concentrations below 10 wt.-% iron. Apart of the outer and inner dimensions to be machined, the neat net shaped tolerances of castings for the rings / disks are sufficient for leaving the other surfaces unmachined. The intrinsic roughness of castings increases the inner surface area and is therefore beneficial for the catalytic efficiency.Oxidic Compounds

[0054] Corrosion resistance of many metals is provided by a passive film, preferably a non-porous oxide layer at the surface of a metallic material, either spontaneously formed on the metal surface or intentionally prepared by a special technique. This is called passivation of nascent metal so a dense, non-porous oxidic layer is formed, which “isolates” / “separates” the metal from the environment or surrounding media.

[0055] The functional effects of the molybdenum-&nickel-containing alloys are derived from their surface chemistry in combination with the turbulent flow, which can consist of metallic and / or oxidized forms. In the present case, oxidized, hydrated or hydrolyzed molybdenum and nickel compounds are preferably effective. Stainless steels or rust- and acid-resistant alloys form a natural oxide layer on their surfaces in air or a passivating layer that protects against corrosive attack.

[0056] Table 2 compiles the different catalytically active oxidic compounds. Fortunately, the compounds mentioned in table 2 all have a catalytic effect to varying degrees. There is therefore a broad spectrum of different, catalytically active compounds present on the surface. Their presence, nature and ratios depend from the surrounding conditions for their formation.

[0057] The water solubility is a criteria for selection, because water soluble oxidic compounds will be irreversibly loosed from the surfaces and limiting lifetime. This is a distinction between hydrous and anhydrous applications. All substances in table 2 have either a CAS or EINECS registry number, even a powder diffraction file number (e.g. JCPDS), which indicate, that all are real existing and well described compounds.

[0058] Note that CAS refers to Chemical Abstracts Service; a unique and unambiguous identifier for a specific substance. Similarly, EINECS refers to European inventory of existing commercial chemical substances; an inventory of substances that were deemed to be on the European Community market.TABLE 2Catalytically active oxidic compoundsRegistrationnumber [CAS]Compound nameFormulaValence{EINECS}CommentsNickelNickel oxideNiONi2+[34492-97-2,11099-02-8]{234-323-5}Dinickel trioxideNi2O3Ni3+[1314-06-3]Ni3O4Ni2+, Ni3+[12137-09-6]Mixte oxidesNickeldihydroxideNi(OH)2Ni2+[12054-48-7]Insoluble in water“light green”(108 μg / L at 20° C.and pH 8.3)NickeldihydroxideNi(OH)2Ni2+[11113-74-9]Nickel hydroxideNi2+[36897-37-7]x•hydrateNickel(III)hydroxideNi(OH)3Ni3+[12125-56-3]“nickel black”Nickel oxideNiOOHNi3+[12026-04-9]hydroxide{805-483-9}Nickel oxideβ-NiOOHNi3+[55070-72-9]hydroxideMolybdenumMolybdenumMo2O3Mo4+[1313-29-7]sequioxideMolybdenum dioxideMoO2Mo4+[18868-43-4]Water solubility: 1.1-23.3 mg / L at 20° C.and pH 3.5-5.Molybdenum trioxideα-MoO3Mo6+[1313-27-5]Water solubility: 1g / L at 20° C. and pH2.5.Molybdenum OxideMo4+Mo6+2O8•nH2OMo4+, Mo6+JCPDS card no.IlsemanniteHydrate210574(Mo3O8•nH2O).Naturally occurringmineral.Molybdenum oxideMoO3•H2O[39082-25-2][MoO3 n H20], withdihydraten = ⅓, ½, 1 or 2Molybdenum oxideMoO3•2H2O[25942-34-1]Sidwillite. Naturallydihydrateoccurring mineral.Molybdic acidH2MoO4Mo6+[7782-91-4]675.5 mg / L at 20° C.(MoO2(OH)2)Molybdenum blueMo4O10(OH)2Mo6+, Mo5+[66771-43-5]Sub-oxides of MoO3MonO3n−1, withMo6+, Mo5+Sub-stoichiometric4 ≤ n ≤ 10oxides with planaroxygen defects (e.g.Mo18O52, Mo9O26,Mo8O23, η-Mo4O10).Double oxidesNickel molybdateα- / β-NiMoO4Ni2+, Mo6+[14177-55-0]Water solubility:{238-034-5}4.65 g / L at 20° C. andpH 7Nickel molybdateNiMoO4n•H2OhydrateHybrid Materials

[0059] Hybrid materials are composites made by synergistic combination of at least two distinct types of materials or compounds. Hybrid materials according to the present invention are oxides and mixtures of oxides including hydrated or hydrolysed oxides embedded in or bonded by a metallic matrix as per Table 1 or by any alloys sufficiently resistant to corrosion in respect to the application. Composites or metal matrix composites are synonyms to hybrid materials.

[0060] These hybrid materials are preferably realized by sintering or co-deposited electroplatings or vacuum assisted or thermal spray techniques.Coating of Parts

[0061] Coating of only the surfaces mating with the fluid reduces the component costs and saves materials resources, because only the catalytically effective nickel and / or molybdenum and their compounds are plated in a thickness suited to last the expected lifetime of operation.

[0062] The second advantage is that effective concentrations of catalytically active compounds and metals are maximized. In the case of stainless steel alloys, other present elements may reduce the density of catalytically active centers on the surfaces. Regarding the designs of the devices as per WO 2021 / 108888 and WO 2021 / 217270, electrically insulating PVC can be used for the housing or the shafts / central rods and these surfaces be functionalized by coating these with the disclosed metals and oxidic compounds. The parts can be coated by

[0063] a. Metallic alloys (table 1) or

[0064] b. Oxidic compounds (table 2) and / or

[0065] c. composites or metal matrix composites or hybrid materials.

[0066] It is contemplated that the coatings of any nature should exhibit a certain thickness resulting in a wear stockpile, because they will wear-off due to

[0067] a. Turbulent flows, or

[0068] b. Depending from the fluid, by solvency of oxides, hydrated or hydrolysed oxides, even very small or

[0069] c. Erosion anticipated by entrained particles with the turbulent flows or

[0070] d. Even by a minimal solubility in the media.

[0071] Apart from tolerance requirements, the surfaces coated by thermal spraying techniques remain rough and / or porous. This increases the catalytically active surface area and is an advantage of this coating process.Metallic Alloys

[0072] Metallic coatings composed of Nickel and Molybdenum can be electroplated on any alloys sufficiently resistant to corrosion in respect to the application, which not consequently belong to AISI 316x-, 317x- or 904x-series, or onto thermoplastics.Oxides

[0073] It is preferable to coat oxides, hydrated or hydrolysed form of the oxides, as well as mixtures of these, of the present disclosure by means of thermal spray deposition techniques, more preferably by cold gas spraying, which are well known by the state-of-the-art. Thermal spray deposition techniques include: plasma spraying, either atmospheric or vacuum, high-velocity oxygen fuel (HVOF), detonation gun, and cold gas spraying. The deposition of porous coatings is well known for thermal barrier coatings and not object of claims in this invention.Composites

[0074] Coatings composed of a metallic binder of Nickel-Molybdenum-based alloys with embedded particles of oxides, hydrated or hydrolysed form of the oxides, can be co-deposited by means of electroplating. It is well known by the state-of-the-art how to execute a co-deposition of a metallic matrix with particles from a suspension / suspended in the electrolyte.Porosity

[0075] ISO 10308:2006(en), “Metallic coatings-Review of porosity tests” reviews published methods for revealing pores and discontinuities in coatings. Normally and in general, coatings are deposited in a manner, that they are dense. In view of the catalytic actions of the disclosed substances, the coatings, either by plating or thermal spray techniques, are deposited under parameters, which intentionally create an open or closed porosity. ASTM B243, item #3306, describes an open as a pore communicating with an exterior surface. ISO 20507:2014, item 2.3.23 defines a pore as cavity in a ceramic. Note that pores may be located in the interior or at the surface. Pores at the surface are usually called pits. The catalytically effective surface area is greatly increased by doing so. The open porosity is limited to the coatings and thus to the surface.Roughening of Surfaces

[0076] Alloys and coatings can be roughened by an emery cloth belt with an ANSI grit size smaller than 120 mesh, preferably 36 mesh. The surface roughness is increased by using a grit size of 36 mesh to Ra of 3-4 μm. This type of roughening is required for electroplatings / galvanic coatings, because they naturally deposit quite smoothly. Ra (CLA) is an arithmetic average (CLA=centre line average) of the absolute distances of all profile points from the mean line for a given distance, as defined in EN 10049—Measurement of roughness average Ra and peak count RPc on metallic flat products.

[0077] Mechanical conditioning (in the sense of roughening) of the surface (e.g. shot peening) prior to oxidation induces grain refinement by twinning. The higher grain boundary density facilitates diffusion / migration of Molybdenum and Nickel to the surface promoting NiMoO4 formation in the scale / oxidation layers and enhances the replenishing of Molybdenum and Nickel due to irreversible wear and dissolution of the scales / oxidic layers.Pre-Oxidation of Alloys and Coatings

[0078] Most metals are thermodynamically unstable in air and react with the surrounding media (air, humidity, fluids) to form oxides. In the case of Nickel, Molybdenum or Chromium, the oxide scale grow until the surface is covered with the respective oxide. The layer continues to grow in thickness depending from the diffusion rate of oxygen until the thickness is high enough to slow down the diffusion of oxygen. The surface is thus passivated by a complete layer. The rate of thickening depends by the temperature and / or oxygen partial pressure and / or oxygen diffusivity. Oxide layers can be generated by means of

[0079] a. Pre-oxidation or

[0080] b. Abel black process.Pre-Oxidation

[0081] Such native oxide layers can be grown by static oxidation in air at temperatures above 300° C. or in an oxygen plasma. The time for pre-oxidation can be shortened by increasing the ambient temperature to e.g. 800° C. in air or by increasing the oxygen content far above ˜20 vol.-% oxygen in air.Plasma Oxidation and Deposition

[0082] Cathodic plasma electrolytical oxidation (CPEO), termed also micro-arc oxidation, enables thick coatings of 100-300 μm with a porosity created by the arcs / sparks / discharges during the growth process in water-based electrolytes.

[0083] Cathodic cage plasma deposition (CCDP) is an anhydrous deposition process using a vacuum chamber. The samples are covered with a cathodic metallic screen (perforated cap or cage). The inner surfaces of linings or pipes can be coated by CCDP. The screen or cap or cage are made in the claimed alloys and composites as per tables 1 and 2. Oxidic compounds can be synthesized by detachment of metal atoms from the cage due to ions bombardment into plasma area followed by reaction with gases atoms and their deposition on the sample surface.Abel Black

[0084] “Abel black” is a proprietary surface finishing of stainless steels by ABEL Co., Ltd., 1-1-42, Minami Taishido, Yao-shi, Osaka, 581-0056, Japan. Surface oxides on stainless steels are generated by an electrolytic treatment.Further Considerations and Other Useful Applications

[0085] It is contemplated that the above-discussed techniques are useful in general for applications that experience biofilm buildup, biofouling, corrosion, or other undesirable attacks to a surface. This applies to a coating composed of materials discussed above or a structure made from materials discussed above.

[0086] The techniques may be applied to intermediate materials or structures such as pipe, tubing, sheet, panel, structural shapes (I-beams, angle iron, etc.) and other fundamental elements that are used to manufacture various structures, devices, and / or machines. With pipe or tubing or other hollow elements, the inside, the outside, or both the inside and outside may be coated.

[0087] The techniques may be applied to intermediate products that are used to manufacture finished products. Examples of intermediate products include housings, casings, manifolds, machine parts, subassemblies, and similar products that are used in downstream manufacturing processes to make finished products.

[0088] The techniques may be applied to finished products that are generally used and / or sold as complete products or as components for complete products. Examples include commercial appliances, home appliances, countertops, pumps, tables, vehicle bodies (e.g., boat hulls, aircraft fuselages / wings, automobile bodies / frames), vehicle mufflers, etc.

[0089] A coating according to the techniques may applied to other structure or decorative elements, such as concrete.

[0090] A coating according to the techniques may be applied to equipment, such as farm machinery. Such application will contribute to soil remediation, which can reduce the need to implement the Fenton reaction. The Fenton reaction is a known reaction that is widely used in soil remediation to break down organic pollutants. However, the Fenton reaction has potential adverse effects that must be carefully managed. These effects can impact soil chemistry, structure, microbial life, and long-term fertility.

[0091] For example, application of the Fenton reaction can result in the incomplete oxidation of contaminants, which can lead to the formation of intermediate toxic compounds instead of full mineralization to CO2 and H2O. In contrast, the advanced oxidation processes provided by the coating degrades the contaminants rather than concentrating or transferring them into a diffused phase. As another example, the hydroxyl radicals (·OH) generated by the Fenton reaction are highly reactive and can oxidize and destroy beneficial soil microorganisms. In contrast, the coating provides singlet oxygen for soil remediation and rejuvenation. As another example, the Fenton reaction is most effective at a low pH. However, acidic soil can reduce nutrient availability. Accordingly, post Fenton reaction treatment is required to reduce the acidity level of the soil. High acidity is not required for the coating to be effective.

[0092] The coatings are especially useful for farm machinery that interacts with the soil. Examples include tillage equipment, planting equipment, fertilization and irrigation equipment, harvesting equipment, and soil maintenance equipment.

[0093] Examples of tillage equipment include plows, tillers, rototillers, and cultivators. Examples of planting equipment include seed drills and planters, and transplanters. Examples of fertilization and irrigation equipment include fertilizer spreaders and irrigation systems. Examples of harvesting equipment include combines and harvesters. Examples of soil maintenance equipment include rollers and packers, subsoilers and deep rippers, mulchers, and cover crop seeders.

[0094] The distinction between intermediate and finished products is not strict and these terms are used merely for sake of explanation. In general, devices, structures, products, etc. may be referred to as objects.

[0095] A coating according to the techniques discussed herein may be manufactured and then later applied to any suitable object to attain the benefits of the present invention. For example, the coating may be applied to farming equipment.

[0096] A coating according to the techniques discussed herein may be applied to an object by electroplating, a galvanic process, thermal spraying, cold gas spraying, etc., as discussed above. An object may be fully or partially coated depending on its service requirements.

[0097] In addition, while flow, specifically turbulent flow, of fluid is contemplated as a useful application for the present invention, it is contemplated that at least some (if not all) of the benefits of the techniques discussed herein may also apply to non-flowing fluid.

Claims

1. Material design with a solid surface in a system for electro-catalytic treatment of a fluid under turbulent flow conditions of the fluid to be treated, comprisingi) an alloy of nickel and molybdenum, orii) an oxidic compound of nickel and molybdenum, oriii) a composite or metal matrix composite of ii) in i),whereini) is selected from high molybdenum alloys between 12-50 wt.-% molybdenum and iron contents below 10 wt.-% iron, where Nickel is the balance of the elemental analysis with at least 49 wt.-% Nickel,ii) is selected from oxides, hydrates or hydrolysed oxides of nickel (NiO, Ni2O5, β-NiOOH, γ-NiOOH, Ni(OH)2, Ni(OH)3) and oxides, hydrates or hydrolysed oxides of molybdenum (MoO2, MoO3, Magnéli-typeError! Bookmark not defined. phases of MoO3), Mo3O8xH2O (ilsemannite), e.g. Mo4+Mo6+2O8·nH2O, MoO3·nH20 with n=⅓, ½, 1 or 2, MoO2.5(OH)0.5 or their double oxides (α- / β-NiMoO4, NiMoO4n·H2O),andiii) includes an oxidic compound from ii) embedded in or bonded by a metallic matrix of i).

2. The material design according to claim 1, wherein the alloy is deposited by electroplating, a galvanic process, or thermal spraying.

3. The material design according to claim 2, wherein the substrate is selected from any alloys sufficiently resistant to corrosion in respect to the application.

4. The material design according to claim 1, wherein the alloy is casted.

5. The material design according to claim 1, wherein the alloy is sintered with either on open or closed porosity.

6. The material design according to claim 2, wherein the surface is roughened to Ra of 3-4 μm and above.

7. The material design according to claim 2, wherein the surface is pre-oxidized.

8. The material design according to claim 1, wherein the oxidic compound is composed of individual composition of the said oxides, hydrates or hydrolysed oxides of nickel and molybdenum including their doubles as said by ii).

9. The material design according to claim 1, wherein the oxidic compound is deposited by thermal or cold gas spraying.

10. The material design according to claim 1, wherein oxidic compound is a sintered body with either on open or closed porosity.

11. The material design according to claim 1, wherein 10-90 vol. % of the oxidic compound are embedded in or bonded by a metallic matrix as by that said i) and claim 3 and form a composite or metal matrix composite or hybrid material.

12. The material design according to claim 1, wherein the composite or metal matrix composite or hybrid material is a sintered body with either an open or closed porosity.

13. The material design according to claim 1, wherein the composite or metal matrix composite or hybrid material is deposited by thermal or cold gas spraying.

14. A coating comprising:i) an alloy of nickel and molybdenum, orii) an oxidic compound of nickel and molybdenum, oriii) a composite or metal matrix composite of ii) in i),whereini) is selected from high molybdenum alloys between 12-50 wt.-% molybdenum and iron contents below 10 wt.-% iron, where Nickel is the balance of the elemental analysis with at least 49 wt.-% Nickel,ii) is selected from oxides, hydrates or hydrolysed oxides of nickel (NiO, Ni2O5, β-NiOOH, γ-NiOOH, Ni(OH)2, Ni(OH)3) and oxides, hydrates or hydrolysed oxides of molybdenum (MoO2, MoO3, Magnéli-typeError! Bookmark not defined. phases of MoO3), Mo3O8xH2O (ilsemannite), e.g. Mo4+Mo6+2O8·nH2O, MoO3·nH20 with n=⅓, ½, 1 or 2, MoO2.5(OH)0.5 or their double oxides (α- / β-NiMoO4, NiMoO4n·H2O),andiii) includes an oxidic compound from ii) embedded in or bonded by a metallic matrix of i).

15. An object coated with the coating of claim 14.

16. The object of claim 15, wherein the object is farm machinery.