Amoxidation catalyst with HCN production as a selective by-product

Abstract

A catalytic composition and process useful for converting an olefin selected from the group consisting of propylene, isobutylene or mixtures thereof to acrylonitrile, methacrylonitrile, hydrogen cyanide and acetonitrile and mixtures thereof, wherein the catalyst is increased in selectivity to hydrogen cyanide relative to prior art catalysts.

Description

Amoxidation catalyst with HCN production as a selective by-product Background of the invention Field of invention The present invention relates to an improved catalyst for use in the oxidation of unsaturated hydrocarbons with related unsaturated nitriles which unexpectedly increases the yield of hydrogen cyanide (HCN) product without significantly reducing the yield of saturated nitriles. In particular, the invention relates to an improved catalyst composition for the oxidation of propylene and / or isobutylene to acrylonitrile and / or methacrylonitrile, respectively, as well as hydrogen cyanide (HCN) and acetonitrile products, and an increased selectivity of the catalyst towards hydrogen cyanide compared to prior art catalysts, wherein said catalyst comprises a set of metal oxides comprising bismuth, molybdenum, iron, cerium and other promoter elements, and wherein said catalyst is characterized by the ratio of iron to bismuth and cerium present in the catalyst. Previous context description Catalysts containing oxides of iron, bismuth, and molybdenum, promoted with appropriate elements, have long been used for the conversion of propylene and / or isobutylene at elevated temperatures in the presence of ammonia and oxygen (usually in the form of air) to produce acrylonitrile and / or methacrylonitrile. In particular, British Patent 1436475; United States Patents 4,766,232; 4,377,534; 4,040,978; 4,168,246; 5,223,469 and 4,863,891 each relate to bismuth-molybdenum-iron catalysts which may be promoted with Group II elements to produce acrylonitrile. Additionally, U.S. Patents 5,093,299, 5,212,137, 5,658,842, 5,834,394 and CN103418400 relate to bismuth-molybdenum promoted catalysts that demonstrate high yields for acrylonitrile. In part, the instant invention relates to a cerium-promoted iron-bismuth-molybdenum catalyst that contains higher amounts of a cerium-bismuth-molybdenum phase with a scheelite crystal structure than previously produced catalysts of substantially similar nature. Such catalysts are taught in U.S. Patents 8,153,546; 8,258,073; 8,350,075; 8,420,566; 8,455,388; 9,211,572; 9,358,528 and U.S. Publication No. 0175817 / 2016. In part, the instant invention relates to bismuth-molybdenum-iron ammoxidation catalysts that provide enhanced hydrogen cyanide production. U.S. Patent 5,840,648 discloses bismuth-molybdenum-iron ammoxidation catalysts that include calcium that provide enhanced hydrogen cyanide production without significantly reducing acrylonitrile production. U.S. Patent 7,576,232 teaches the addition of various molybdates to ammoxidation catalysts to modify catalyst performance to enhance hydrogen cyanide production and inhibit molybdenum loss from such ammoxidation catalysts. Summary of the invention This invention relates to an improved process and catalyst for the synthesis of propylene to acrylonitrile, hydrogen cyanide and acetonitrile. The process and catalyst are characterized by a greater overall conversion of propylene to hydrogen cyanide and a greater overall conversion of propylene to acrylonitrile, hydrogen cyanide and acetonitrile than previously available in other processes and catalysts. Historically, catalysts that have increased the yield of hydrogen cyanide have been accompanied by a corresponding decrease in the yield of acrylonitrile. The catalysts of the instant invention do not conform to this historical trend. The process and catalyst of the instant invention provide for increased production of hydrogen cyanide without a significant decrease in the production of acrylonitrile and provide for an overall increase in the production of acrylonitrile, hydrogen cyanide and acetonitrile. In one embodiment, this invention relates to a catalytic composition comprising a set of metal oxides, the relative proportions of the elements mentioned in said catalyst being represented by the following formula: MomBiaFebAcDdEeFfGgCehCrnQqOx Where: A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium. At least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium. E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium, and tellurium. F is at least one element selected from the group consisting of lanthanum, europium, gadolinium, terbium, dysprosium, helmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, lead, silicon and germanium; G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury. Q is at least one of cerium, praseodymium, and neodymium, and A, b, c, d, e, f, g, h, n, m, and x are the atomic ratios of bismuth (Bi), iron (Fe), cerium (Ce), chromium (Cr), molybdenum (Cr), and oxygen (O), respectively, relative to "m" molybdenum (Mo) atoms, where: A is 0.05 to 7, B is 0.1 to 7, C is 0 to 5, D is 0.1 to 12, E is 0 to 5, F is 0 to 5, G is 0 to 0.2, H is 0.01 to 5, M is 10 to 15, N is 0 to 5, Q is 0 to 2.476, and X is the number of oxygen atoms required to meet the capacity requirements of the other available effective elements; and where 0.4 < b / (a+h) and 0.3 ≤ (a+h) / d. In other experiments, the above combination, independently 0.3 ≤ (a+h) / d ≤ 1, 0.8 ≤ h / b ≤ 5, 0.5 ≤ a / h < 1.5, 0.45 ≤ (a+h) / d ≤ 1, 0 ≤ q / (a+h+q) < 0.16, and / or 0 ≤ m – (3a+2b+c+2d+3h+3n) / 2 ≤ 1.0. The invention also relates to a propylene detoxification catalyst formulation capable of providing a variable and reversible range of useful nitrile yields including acrylonitrile and HCN. This variation in yield can be achieved by the appropriate addition of specific catalyst additives. In particular, the yield of hydrogen cyanide is increased with respect to the amount of acrylonitrile and methacrylonitrile produced in the process by adding to the catalyst at least one molybdate compound produced by this formulation. A2MoZO4+3(z-1) where A is Rb, Li, Na, K, Cs or a combination thereof, and Z ranges from 1 to about 8. Alkali molybdate may be used with or without support. Furthermore, where a molybdate is added to the catalyst to increase the production of hydrogen cyanide, the process is reversible by adding a molybdenum oxide compound selected from the group consisting of MoO3, ammonium molybdate, ammonium heptamolybdate, ammonium dimollite and related compounds to the catalyst and alkali molybdate which catalyzes the amidation process. Thus, the addition of molybdenum oxide to the molybdate catalyst and alkali mixture increases the yield of acrylonitrile and methacrylonitrile relative to the amount of hydrogen cyanide produced in the process (i.e. the amount of acrylonitrile and methacrylonitrile produced and the hydrogen cyanide will be stored near, or at excess levels before the molybdate). Detailed description of the invention This invention is directed to an improved mixed metal oxide catalyst and process for the amylation of propylene and / or isobutylene. More particularly, this invention is directed to an improved catalytic composition for the conversion of propylene and / or isobutylene to acrylonitrile and / or methacrylonitrile, respectively, and to the production of hydrogen cyanide (HCN) and acetonitrile products, said catalyst providing increased selectivity to hydrogen. Cyanide as compared to prior art catalysts, wherein said catalyst comprises a set of metal oxides comprising bismuth, molybdenum, iron, cerium and other promoter elements, and wherein said catalyst is characterized by the ratio of iron to bismuth and cerium present in the catalyst. . As used herein, "catalytic composition" and "catalyst" are synonymous and are used interchangeably. Catalyst: In part, this invention provides a multi-component mixed metal oxidation catalytic composition comprising a set of catalytic oxides, wherein the elements and relative proportions of the elements present in the catalytic composition are listed, with the following formula: MomBiaFebAcDdEeFfGgCehCrnQqOx wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium; D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium. E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium, and tellurium. F is at least one element selected from the group consisting of lanthanum, europium, gadolinium, terbium, dysprosium, helmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, lead, silicon and germanium; G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury. Q At least one of cerium, praseodymium, and neodymium, and A, b, c, d, e, f, g, h, n, m, and x are the atomic ratios of bismuth (Bi), iron (Fe), A, D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo), and oxygen (O), respectively, relative to "m" atoms of molybdenum (Mo); in which A is 0.05 to 7, B is 0.1 to 7, C is 0 to 5, D is 0.1 to 12, E is 0 to 5, F is 0 to 5, G is 0 to 0.2, H is 0.01 to 5, M is 10 to 15, N is 0 to 5, Q is 0 to 2.476, and X is the number of oxygen atoms required to meet the capacity requirements of the other available effective elements; and where 0.4 < b / (a+h) and 0.3 ≤ (a+h) / d. In one experiment, A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium. In one experiment, the catalytic composition is potassium-free. In an experiment, D is at least one element from the group consisting of nickel, cobalt, and magnesium. In an experiment, D is nickel. In one experiment, the catalyst is free of tellurium, antimony or selenium. In another experiment, the components or elements designated by "E" in the above formula may also include tellurium and / or antimony. In another experiment, the components or elements designated by "E" in the above formula are at least one element selected from the group consisting of chromium, aluminum, gallium, indium, arsenic, antimony and tellurium. In another experiment, "e" is zero (i.e., the above-mentioned compound does not contain any component or element designated by "E" in the above formula). In one experiment, h is from 0.01 to 5. In one experiment, "F" may also include lead (Pb). In another experiment, "F" does not include lead (Pb). In one experiment, "m" is 12. In some cases, the catalytic composition may be characterized by the relationship b / (a ​​+ h), where b is the relative amount of iron in the catalyst, a is the relative amount of bismuth in the catalyst, and h is the relative amount of cerium. In one experiment, 0.4 < b / (a + h), in another independent experiment, 0.45 ≤ b / (a + h). In part, the catalyst composition may be specified by the relationship (a+h) / d, where "a" is the relative amount of bismuth in the catalyst, "h" is the relative amount of cerium in the catalyst, and "d" is the relative amounts of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium, and barium in the catalyst. These relative amounts are the elements present in the catalyst formula, or in the case of "d" is the sum of the shares of the catalyst formula for any nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium, and barium present in the catalyst. In one experiment, 0.3 ≤ (a+h) / d. In another independent experiment, 0.15 ≤ (a+h) / d, other independent experiments (each line below an experiment) are: 0.15 ≤ (a+h) / d ≤ 1, 0.3 ≤ (a+h) / d ≤ 1, 0.3 ≤ (a+h) / d ≤ 0.8, 0.3 ≤ (a+h) / d ≤ 0.6, 0.3 ≤ (a+h) / d ≤ 0.4, (a+h) / d ≤ 1, (a+h) / d ≤ 0.8, (a+h) / d ≤ 0.6, (a+h) / d ≤ 0.5, and (a+h) / d ≤ 0.4 The catalyst composition may also be specified by the formula "m minus [(3a + 2b + c + 2d + 3h + 3n) / 2]" where "m" is the relative amount of molybdenum in the catalyst, "a" is the relative amount of bismuth in the catalyst, "b" is the relative amount of iron in the catalyst, "c" is the relative amount of elements "A" (lithium, sodium, potassium, rubidium and cesium) in the catalyst, "d" is the relative amount of elements "D" (i.e. nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium) in the catalyst, "h" is the relative amount of cerium in the catalyst and "n" is the relative amount of chromium in the catalyst. These relative amounts are the elements present in the catalyst formula or in the case of "a" the total amount of common elements present in the catalyst formula for each type of lithium, sodium, potassium, rubidium and cesium present in catalyst and in the case of "d" the sum of the common denominators of the catalyst formula for any nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium present in the catalyst. In an experiment, 0 ≤ [m minus [(3a+2b+c+2d+3h+3n) / 2]] ≤ 1.0 In one experiment, "Q" is samarium. In another experiment, the catalyst does not contain the element "Q" (i.e., "q" is zero). In other experiments, "q" is greater than zero. In another experiment, "q" ranges from 0 to 2.476. The catalytic composition may be characterized by the relationship q / (a + h + q), where "q" is the relative amount of samarium, praseodymium, and neodymium in the catalyst, where "a" is the relative amount of bismuth in the catalyst, and "h" is the relative amount of cerium in the catalyst. These are the relative amounts of the elements in the catalyst formula, or in the case of "q" the sum of the shares of the catalyst formula for each samarium, praseodymium, and neodymium present in the catalyst. In one experiment, 0 ≤ q / (a + h + q) and q / (a + h + q) < 0.16. In another experiment, 0 ≤ q / (a + h + q) and q / (a + h + q) < 0.05. In another experiment, 0.01 0 ≤ q / (a+h+q), 0.01 < q / (a+h+q), 0.02 < q / (a+h+q), 0.03 < q / (a+h+q), 0.04 < q / (a+h+q), q / (a+h+q) < 0.16,​ q / (a+h+q) < 0.14, q / (a+h+q) < 0.12, q / (a+h+q) < 0.10, q / (a+h+q) < 0.08, q / (a+h+q) < 0.06, and q / (a+h+q) < 0.05. The catalytic composition may also be characterized by the relationship h / b, where h" is the relative amount of cerium in the catalyst and b" is the relative amount of iron in the catalyst. These are the common relative amounts of the elements in the catalyst formula. In one experiment, 0.8 ≤ h / h / 5 ≤ 5. Other independent experiments (each row below one experiment) are: 1.2 ≤ h / b ≤ 5, 1.5 ≤ h / b ≤ 5, 1.2 ≤ h / b, 1.5 ≤ h / b, 0.8 ≤ h / b, and h / b ≤ 5 It has been discovered that catalysts described in the range described by 0.8 ≤ h / b ≤ 5 tend to be more robust because they lose less attraction as determined by a submerged jet attraction test. The catalytic composition may also be specified by the relationship (a / h), where a" is the relative amount of bismuth in the catalyst, h" is the relative amount of cerium in the catalyst. These are the common relative amounts of the elements in the catalyst formula. In one experiment, 0 0.2 ≤ a / h ≤ 1.5, 0.3 ≤ a / h ≤ 1.5, 0.4 ≤ a / h ≤ 1.5, 0.45 ≤ a / h ≤ 1.5, 0.5 ≤ a / h ≤ 1.5, 0.2 ≤ a / h, 0.3 ≤ a / h, 0.4 ≤ a / h, 0.45 ≤ a / h, 0.65 ≤ a / h, 0.5 ≤ a / h, 0.7 ≤ a / h, 0.8 ≤ a / h, 0.90 ≤ a / h, a / h ≤ 1.2, and a / h ≤ 1.5 In an alternative embodiment of the instant invention catalyst, the invention is a catalytic composition comprising a set of metal oxides wherein the relative proportions of said elements in said catalyst are represented by the following formula: MomBiaFebAcDdEeFfGgCehNiiCojMnkMglQqOx ​wherein A is at least one element selected from the group consisting of sodium, potassium, rubidium and cesium. and D At least one element is selected from the group consisting of zinc, calcium, strontium, cadmium and barium. E is at least one element selected from the group consisting of chromium, tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium, and tellurium. F is at least one element selected from the group consisting of lanthanum, europium, gadolinium, terbium, dysprosium, helmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, germanium and less than 10 ppm lead. G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury. Q is at least one of cerium, praseodymium, and neodymium, and where a is 0.05 to 7, B is 0.1 to 7, C is 0.01 to 5, D is 0 to 12, E is 0 to 5, F is 0 to 5, G is 0 to 0.2, H is 0.01 to 5, I is 0.1 to 12, J is 0 to 12, K is 0 to 12, L is 0 to 12, M is 10 not 15, Q is 0 to 2.476 X is the number of oxygen atoms required to meet the capacity requirements of the other available effective elements; and where 0.4< b / (a+h), 0.2 < i / (i+j+k+l), and, where z = d+i+j+k+l and 0.3 ≤ (a+h) / z. The catalyst of the present invention may or may not be supported (e.g., the catalyst may be a support). Suitable supports are silica, alumina, zirconia, titania, or mixtures thereof. A support typically acts as a binder for the catalyst and results in a stronger catalyst (i.e., greater resistance to adsorption). However, for commercial applications, a suitable combination of both the active phase (e.g., the catalytic oxide complex described above) and the support is critical to obtaining an acceptable activity and hardness (resistance to adsorption) for the catalyst. Typically, the support will comprise from 40 to 60 percent by weight of the catalyst being supported. In one embodiment of the invention, the support may comprise approximately 30 percent by weight of the supported catalyst. In another embodiment of this invention, the retainer may comprise approximately 70% by weight of the retained catalyst. In one embodiment, the catalyst is supported using a silica material. Typically, the silica solids contain some sodium. In one embodiment, the silica solution contains less than 600 ppm sodium. In another embodiment, the silica solution contains less than 200 ppm sodium. Typically, the average diameter of the colloidal particles of the silica solution is between about 15 nm and about 50 nm. In one embodiment of the invention, the average diameter of the colloidal particles of the silica sol is between about 10 nm and can be as small as about 4 nm. In another embodiment of the invention, the average diameter of the colloidal particles of the silica material is between about 100 nm. In another embodiment of the invention, the average diameter of the colloidal particles of the silica sol is between about 20 nm. In another embodiment of the invention, the average diameter of the colloidal particles of the silica sol is between about 40 nm. Use of nitrogen The instant invention also defines a novel process and catalyst for the production of acrylonitrile, acetonitrile and hydrogen cyanide characterized by the relative yields of acrylonitrile, acetonitrile and hydrogen cyanide produced in the process and / or by the catalyst by:  = [(%AN + (3 × %HCN) + (1.5 × %ACN)) ÷ %PC] × 100 where %AN is the acrylonitrile yield and %AN > 82, %HCN is the yield of hydrogen cyanide and %HCN > 5, %ACN is the yield of acetonitrile, %PC is the propylene conversion, and  is greater than 102.5. In other experiments, independently, %AN is greater than or equal to 82.5%; %PC is greater than 90; %PC is greater than 95; %PC is greater than 98; and  is greater than 103. As used herein, "acrylonitrile yield" means the mole percent of acrylonitrile (expressed numerically without any percentage sign) calculated as follows: (moles of acrylonitrile produced ÷ moles of propylene fed to the reactor × 100. "Hydrogen cyanide yield" means the percent molar yield of hydrogen cyanide (expressed numerically without any percentage sign) calculated as follows: [(moles of hydrogen cyanide produced ÷ 3) ÷ moles of propylene fed to the reactor] × 100. "Acetonitrile yield" means the percent molar yield of acetonitrile (expressed numerically without any percentage sign) calcined as follows: [(moles of acetonitrile produced ÷ 1.5) ÷ moles of propylene fed to the reactor] × 100.Propylene conversion means the percentage molar conversion of propylene to products and by-products (in numerical form without any percentage sign), which is calculated as follows: [(moles of propylene fed to the reactor minus moles of propylene leaving the reactor) - moles of propylene fed to the reactor] × 100. """ is a scale measuring "nitrogen insertion" or "nitrogen utilization" (i.e., nitrogen from ammonia combines with propylene to form compounds having a "CN" functional group during the oxidation reaction; thus, the greater "", the greater the overall conversion of propylene to acrylonitrile, hydrogen cyanide, and acetonitrile). The catalyst of the instant invention is characterized by a high """ (i.e., greater than 102.5) with a scale measuring how efficient the catalyst is in utilizing ammonia for the ammoniation of propylene to acrylonitrile. Catalyst preparation: The catalyst may be prepared by any of a number of catalyst preparation methods known to those skilled in the art. A typical preparation method begins by forming a mixture of water, a molybdenum source compound, and a support material (e.g., a silica solution). Separately, the remaining element source compounds in the catalyst are combined in water to form a second mixture. The two mixtures are then combined with stirring at a slightly elevated temperature (approximately 65°C) to form a catalyst precursor solution. The catalyst precursor solution is then dried and nitrate-free as described. In one experiment, the elements in the catalyst composition identified above are combined together in an aqueous catalyst precursor solution, the resulting precursor solution is dried to form a catalyst precursor, and the catalyst precursor is calcined to form the catalyst. However, the following are unique to the process of the instant invention: (a) combining, in aqueous solution, source compounds of Bi and Ce, and optionally one or more of Na, K, Rb, Cs, Ca, lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thallium, ytterbium, lutetium, scandium, yttrium, lead and W to prepare a mixture (i.e., a first mixture), (b) adding a molybdenum source to the mixture (i.e., the first mixture) to react with the mixture and form a precipitate solution, and (c) combining the precipitate solution with the remaining element source compounds and the remaining molybdenum in the catalyst to form an aqueous catalyst precursor solution. As used herein, "source compositions" are compositions that include or provide one or more metals for the composition of the mixed metal oxide catalyst. As used herein, "residual elements" or "residual elements in the catalyst" refers to those elements and amounts of those elements represented by "A", "D", "E", "F" and "G" in the above formula that are not included in the first composition. In an experiment, some elements may be part of the first and second mixtures. In addition, as used herein, "residual molybdenum" or "residual molybdenum in the catalyst" refers to that amount of molybdenum required in the finished catalyst that was not present (i.e., not included in its preparation) in the precipitation solution. Consequently, the sum of the amounts of molybdenum present in the molybdenum source compositions added in (b) and (c) is equal to the total amount of molybdenum present in the catalyst. In the preparation of the above catalyst, the residual element source compounds and residual molybdenum that are combined with the precipitation solution may be combined with any order or combination of these residual elements and residual molybdenum. In one experiment, a mixture of the residual element source compounds and residual molybdenum is combined with the precipitation solution to form an aqueous catalyst precursor solution. In another experiment, (a) a mixture of the residual element source compounds is combined with the precipitation solution, and (b) the residual molybdenum source compounds are added separately to the precipitation solution to form an aqueous catalyst precursor solution. In another experiment, the residual element source compounds and residual molybdenum are added separately (e.g., one at a time) to the precipitation solution.In another experiment, several mixtures (i.e., more than one) of source compounds of residual elements and residual molybdenum, wherein each mixture contains one or more source compounds of residual elements or residual molybdenum, are added separately (i.e., one mixture at a time or several mixtures added simultaneously) to the precipitation solution to form an aqueous catalyst precursor solution. In another experiment, a mixture of the source compounds of the elements is combined with a molybdenum source compound and the resulting mixture is then added to the precipitation solution to form a catalyst precursor solution. In another experiment, the support is silica (SiO2) and the silica is combined with the source compound for residual molybdenum before the residual molybdenum is combined with the precipitation solution (i.e., silica and a source compound for residual molybdenum) to form the mixture and then this mixture is added to the precipitation solution, either separately or in combination with one or more source compounds of residual elements). In the preparation of the above catalyst, molybdenum is added both in the preparation of the precipitation solution and in the preparation of the aqueous catalyst precursor solution. At the atomic level, the minimum amount of molybdenum added to form the precipitation solution is determined by the following relationships Mo = 1.5(Bi+Ce) + 0.5(Rb+Li+Na+K+Cs) + (Ca) + 1.5 The total number of atoms of lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, helmium, erbium, thallium, ytterbium, lutetium, scandium, and yttrium) + (lead) - W)) In this relation, "Mo" is the number of molybdenum atoms to be added to the first compound, and "Bi", "Ce", "Rb", "Li', "Na" "K", "Cs", "Ca", "Pb" and "W" are the numbers of bismuth, cerium, rubidium, lithium, sodium, potassium, cesium, calcium, lead and tungsten atoms respectively present in the first compound. In the above catalyst preparation, typically, the amount of molybdenum added to the first mixture to form the precipitation solution is about 20 to 35% of the total molybdenum present in the final catalyst. In one experiment, a source compound for the residual molybdenum present in the catalyst is added to the mixture of the residual element source compounds (i.e., the second mixture) before the mixture of the residual element source compounds is combined with the precipitation solution to form the catalyst precursor solution. In other experiments, a molybdenum source containing the residual molybdenum present in the catalyst is added to the precipitation solution either before, after, or simultaneously with the mixture of the residual element source compounds (i.e., the second mixture) to form the catalyst precursor solution. In the above preparation, the source compounds Bi and Ce, and optionally one or more of Li, Na, K, Rb, Cs, Ca, a rare earth element, lead and W, are combined in an aqueous solution to form a mixture. In one experiment, bismuth nitrate and other metal nitrates (e.g., Li, Na, K, Rb, Cs, Ca, a rare earth element and / or lead nitrate) are dissolved in an aqueous solution of ceric ammonium nitrate. If tungsten is added, the source compound is typically ammonium paratungstate, (NH4)10H2(W2O7)6. As used herein, "rare earth element" means at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, helmium, erbium, thallium, ytterbium, scandium and yttrium. A mixture containing bismuth and cerium (and optionally one or more of Li, Na, K, Rb, Cs, Ca, a rare earth element, Pb and / or W) is a source of molybdenum. In one experiment, this molybdenum source compound is water-soluble ammonium heptamolybdate. By adding the molybdenum source compound to the mixture containing bismuth and cerium, a reaction will occur that causes precipitation, and the resulting mixture is the precipitate solution. The precipitation solution is then combined with a mixture of the source composition of the remaining elements from the catalyst and a molybdenum source to form an aqueous catalyst precursor solution. The mixture of the source compositions of the remaining elements and a molybdenum source may be prepared by combining the source compositions of the remaining elements in an aqueous solution (e.g., the source compositions are combined in water) and then adding a molybdenum source. In one experiment, this molybdenum source composition is water-soluble ammonium heptamolybdate. When combining the precipitation solution with the remaining molybdenum elements / mixture, the order of addition is not critical, i.e., the precipitation solution may be added to the remaining molybdenum elements / mixture or the remaining molybdenum elements / mixture may be added to the precipitation solution. The aqueous catalyst precursor solution is maintained at an elevated temperature. The amount of aqueous solvent in each of the above aqueous mixtures and solutions may vary due to the solubility of the compound source compounds to form the specific mixed metal oxide. The amount of aqueous solvent should be at least sufficient to obtain a solution or mixture of solids and liquids that is miscible. In any case, the source compounds are preferably compounded by a protocol that includes mixing the source compounds in the compounding and / or reaction step. The specific mixing mechanism is not critical and can include, for example, mixing (e.g., stirring or agitation) during the reaction by any effective method of compounding. Such methods include, for example, agitating the contents of the vessel, for example, by shaking, swirling or oscillating the vessel containing the compound. Such methods also include, for example, stirring using a stirring member that is at least partially within the reaction vessel and the driving force is coupled to the stirring member or the reaction vessel to create relative motion between the stirring member and the reaction vessel. The stirring member can be a drive member or a shaft. The driving force can be directly coupled to the stirring member or can be indirectly coupled to the stirring member (e.g., via a magnetic coupling).Mixing is generally preferred to mix the components sufficiently to allow effective reaction between the components of the reaction medium to occur, resulting in a more homogeneous reaction medium (i.e., and thus a more homogeneous mixed metal oxide precursor) than would be the case in an unmixed reaction. This results in better utilization of the starting materials and a more uniform mixed metal oxide product. Mixing the precipitation solution during the reaction step also allows the precipitate to form in solution rather than on the sides of the reaction vessel. Of further advantage, having the precipitate form in solution allows for particle growth on all sides of the particle rather than being confined to the exposed areas as it grows from the walls of the reaction vessel. A molybdenum source compound may include molybdenum (VI) oxide (MoO3), ammonium heptamolybdate, or molybdic acid. The molybdenum source compound may be derived from any molybdenum oxide such as the dioxide, trioxide, pentoxide, or heptoxide. However, it is preferred to use a hydrolyzable or degradable molybdenum salt as the molybdenum source compound. Typical source compounds for bismuth, cerium, and the remaining elements from the catalyst are metal nitrate salts. Such nitrate salts are readily available and readily soluble. A bismuth source may consist of an oxide or a salt formed during the propagation of the oxide. Water-soluble salts that are easily dispersed but form stable oxides upon heat treatment. In one experiment, the bismuth source is bismuth nitrate, Bi(NO3)3·5H2O. A cerium source compound may consist of an oxide or a salt that, upon calcination, yields the oxide. Water-soluble salts that are readily dispersed but form stable oxides upon heat treatment. In one experiment, the cerium source compound is ceric ammonium nitrate, (NH4)2Ce(NO3)6. In another experiment, the cerium source compound is ceric nitrate, Ce(NO3)3·6H2O. An iron source compound may include any iron compound that produces an oxide upon calcination. As with other elements, water-soluble salts are preferred for the ease with which they may be uniformly dispersed within the catalyst. Iron nitrate is preferred. The source compounds for the remaining elements may be obtained from any suitable source. For example, cobalt, nickel and magnesium may be introduced into the catalyst using a nitrate salt. In addition, magnesium may be introduced into the catalyst as an insoluble carbonate or hydroxide which, after heat treatment, results in an oxide. Phosphorus may be introduced into the catalyst as an alkali metal salt or an alkaline earth metal salt or an ammonium salt but is preferably introduced as phosphoric acid. The source compounds for the alkaline components of the catalyst may be introduced into the catalyst as an oxide or as a salt that produces an oxide upon calcination. Solvents other than water may be used to prepare the mixed metal oxides of the invention, including, but not limited to, alcohols such as methanol, ethanol, propanol, diols (e.g., ethylene glycol, propylene glycol, etc.), organic acids such as acetic acid, as well as other polar solvents known in the art. The metal source compounds are at least partially soluble in the solvent. As previously mentioned, the catalyst of the present invention may or may not be protected (i.e., the catalyst may be a protector). Suitable protectors are silica, alumina, zirconia, titania, or mixtures thereof. The protector may be added at any time before the catalyst precursor solution is dried. The protector may be added at any time during or after the preparation of any mixture of elements, the precipitate solution, or the catalyst precursor solution. Furthermore, the support does not need to be added at a single point or step (i.e., the support may be added at multiple points in the preparation). In one experiment, the support is incorporated during the preparation of the aqueous catalyst precursor solution. In one experiment, the support is added to the precipitation solution (i.e., after the precipitation solution has been prepared). In one experiment, the support is combined with the molybdenum source composition before the molybdenum source composition is combined with the remaining element source composition. In the catalyst to form the "second mixture" referred to above. The catalyst precursor solution is dried and removed (i.e., nitrates are removed) for catalyst precursor function. In one experiment, the catalyst precursor solution is dried to form catalyst particles. In one experiment, the catalyst precursor solution is sprayed onto microspheroidal catalyst particles. In one experiment, the outlet temperature of the spray dryer is between 110 and 350°C. The outlet temperature of the dryer is preferably between 110 and 250°C, preferably between 110 and 180°C. In one experiment, the spray dryer is a co-current spray dryer (i.e., the particles are sprayed simultaneously into the gas stream). In another experiment, the spray dryer is of the counter-current type (i.e., the particles are sprayed against the gas stream). In another experiment, the spray dryer is of the pressure nozzle type. In such spray drying steps, the water-containing solid phase particles are sprayed into contact with a hot gas (usually air) to evaporate the water. Drying is controlled by the temperature of the gas and the distance the particles travel in contact with the gas.It is usually undesirable to adjust these parameters to achieve excessive drying because this leads to the formation of dry flakes on the partially dried particles of the solid phase which later rupture due to the decomposition of water within the particles and attempt to escape. By the same token, it is desirable to prepare the catalyst in a form with little water retention. Therefore, where a fluidized bed reactor is to be used and microspheroidal particles are desired, it is advisable to select spray drying conditions to achieve complete drying without particle rupture. The dried catalyst material is then heated to remove residual nitrate. The denitrification temperature may be from 100°C to 500°C, preferably from 250°C to 450°C. Finally, the dry, undesorbed catalyst precursor is calcined to form the finished catalyst. In one experiment, the calcination is carried out in air. In another experiment, the calcination is carried out in an inert atmosphere. In one experiment, the catalyst precursor is calcined in nitrogen. The calcination conditions include temperatures from about 300°C to about 700°C, preferably from about 350°C to about 650°C, and in some experiments may be carried out at about 600°C. In one experiment, the calcination may be carried out in multiple stages of increasing temperature. In one experiment, the first calcination stage is carried out at a temperature in the range of about 300°C to about 450°C, and in a subsequent stage, a second calcination stage is carried out at a temperature in the range of about 500°C to about 650°C. . Detoxification process The catalysts of the instant invention are useful in detoxification processes for converting an olefin selected from the group consisting of propylene, isobutylene or mixtures thereof, to acrylonitrile, methacrylonitrile and mixtures thereof, respectively, by reacting in the vapor phase at elevated temperature. and pressurizing said olefin with molecular oxygen containing gas and ammonia in the presence of the catalyst. The catalysts of the instant invention are also useful for the oxidization of methanol to hydrogen cyanide and the oxidation of ethanol to acetonitrile. In an experiment using the catalysts described herein, methanol and / or ethanol can be simultaneously introduced into a process for the detoxification of propylene, isobutylene or mixtures thereof to acrylonitrile, methacrylonitrile or mixtures thereof in order to enhance the production of hydrogen cyanide and / or acetonitrile products resulting from such a process. Preferably, the amixidation reaction is carried out in a fluidized bed reactor, although other types of reactors, such as conveyor line reactors, are contemplated. Fluidized bed reactors are well known in the prior art for the production of acrylonitrile. For example, the reactor design disclosed in U.S. Pat. No. 3,230,246, which is incorporated herein by reference, is suitable. The conditions for the oxidation reaction also occur as is evident from the prior art, as evidenced by U.S. Pat. Nos. 5,093,299; 4,863,891; 4,767,878 and 4,503,001; incorporated herein by reference. Typically, the olefination process is carried out by contacting propylene or isobutylene in the presence of ammonia and oxygen with a fluidized bed catalyst at elevated temperatures to produce acrylonitrile or methacrylonitrile. Any source of oxygen may be used. However, for economic reasons, the use of air is preferred. The typical molar ratio of oxygen to olefin in the feed should be from 0.5:1 to 4:1, preferably from 1:1 to 3:1. The molar ratio of ammonia to olefin in the feed to the reaction may be between 0.5:1 and 2:1. There is no real upper limit on the ratio of ammonia to olefin, but there is generally no reason to exceed a ratio of 2:1 for economic reasons. Suitable feed ratios for use with the catalyst of the instant invention for the production of acrylonitrile from propylene are ammonia to propylene ratios in the range of 0.9:1 to 1.3:1 and air to propylene ratios of 8.0:1 to 12.0:1. The catalyst of the instant invention is capable of providing high yields of acrylonitrile at relatively low ammonia to propylene feed ratios of about 1:1 to about 1.05:1. These “low ammonia conditions” help reduce unreacted ammonia in the reactor effluent, a condition called “ammonia recovery,” which later helps reduce process wastes. Specifically, unreacted ammonia must be removed from the reactor effluent before acrylonitrile can be recovered.The deactivated ammonia is typically removed by contacting the reactor effluent with sulfuric acid to obtain ammonium sulfate or by contacting the reactor effluent with acrylic acid to yield ammonium acrylate, in both cases resulting in a process waste stream for treatment and / or disposal. The reaction is carried out at a temperature between about 260 and 600°C, with preferred ranges being 310 to 500°C, particularly preferred being 350 to 480°C. The contact time, although not critical, is generally between 0.1 and 50 seconds, and preferably the contact time is 1 to 15 seconds. The reaction products may be recovered and purified by any of the methods known to those skilled in the art. One such method is to scrub the reactor exhaust gases with cold water or a suitable solvent to remove the reaction products and then purify the reaction product by distillation. The main catalyst tool prepared by the process of the instant invention is for the decarboxylation of propylene to acrylonitrile. Other applications of these devices include any of the oxidation of propane to acrylonitrile, the oxidation of an alcohol selected from the group consisting of methanol, ethanol or mixtures thereof, to hydrogen cyanide (HCN), acetonitrile and mixtures thereof, and the amixidation of glycerol to acrylonitrile. . The catalyst prepared by the process of the instant invention may also be used for the oxidation of propylene to acrolein and / or acrylic acid. Such processes are typically two-step processes in which, in the first step, propylene is converted primarily to acrolein in the presence of a catalyst, and acrolein is converted primarily to acrylic acid in the presence of a catalyst. The catalyst described herein is suitable for use in the first step for the oxidation of propylene to acrolein for use in the first step. Modulating HCN production during detoxification In an experiment of the instant invention, the yield of hydrogen cyanide was increased with respect to the amount of acrylonitrile and methacrylonitrile produced in the process by adding a catalyst of at least one alkali molybdate compound produced by the formula. where A is Rb, Li, Na, K, Cs, or a combination of these, and Z ranges from 1 to about 8. The alkali molybdate compound may or may not be supported on a suitable carrier such as silica, alumina, zirconia, titania or unsupported mixtures. If supported, the supporting or supporting compounds comprise between 1% by weight and 99% by weight of the alkali molybdate compound and the supporting compound. The amount of said alkali molybdate compound added to the catalyst is in the range of 0.01% by weight to 10% by weight based on the weight of said catalyst compound. For the catalytic systems previously described here (i.e. with 0.4 <b (a ​​+ h) و 0.3 ≤ + d) تعریف شده است، افزودن مولیبدات قلیایی به ویژه برای افزایش سطح درج نیتروژن یا مفید است. استفاده، قبلاً در بالا عنوان"a" توصیف این یک اندازه گیری از میزان کارایی کاتالیزور استفاده آمونیاک سم زدایی پروپیلن آکریلونیتریل کاتالیزورهای اختراع فوری توسط "a" زیاد (یعنی بزرگتر 102.5) مشخص می شود که آکریلونتریل است.In addition, where an alkali molybdate compound is added to the catalyst to increase hydrogen cyanide production, the process is reversible by adding a molybdenum oxide compound selected from the group consisting of MoO3, ammonium molybdate, ammonium heptamolybdate, ammonium dimolybdate, and mixtures thereof to the catalyst and the alkali molybdate mixture which catalyzes the amidation process. Thus, the addition of the molybdenum oxide compound to the catalyst and alkali molybdate mixture increases the yield of acrylonitrile and methacrylonitrile relative to the amount of hydrogen cyanide produced in the process (i.e., the amount of acrylonitrile and / or methacrylonitrile produced increases to or approaches the level present prior to the addition of the alkali molybdate and the amount of hydrogen cyanide decreases to or approaches the level present prior to the addition of the alkali molybdate). The molybdenum oxide composition may be unsupported or may be supported on a suitable carrier such as silica, alumina, zirconia, titania, or other mixtures.If retained, the retainer or carrier comprises between 1% by weight and 99% by weight of the molybdenum oxide composition and the support composition. The amount of said molybdenum oxide composition added to the catalyst is in the range of 0.01% by weight to 10% by weight, based on the weight of said catalyst composition. The alkali molybdate compound and / or molybdenum oxide compound may be added to the catalyst in situ, for example while the catalyst is operating in the reactor, or it may be added to the catalyst external to the reactor. In one experiment, the alkali molybdate compound or molybdenum oxide compound is added to (i.e. mixed with) fresh fluidized bed detoxification catalyst which is then added to the reactor as a "make-up" catalyst to maintain the catalyst bed height in the reactor and to replace catalyst that is lost to the reactor in the effluent or by gravity. Special experiences In order to demonstrate the instant invention, the catalyst prepared in accordance with the instant invention was examined and compared under similar reaction conditions with similar catalysts prepared by prior methods outside the scope of the instant invention. These examples are provided for illustrative purposes only. The catalyst compositions, for each example, are indicated as in the example number. The examples marked with "C" are comparative examples. Example C1 - Ni4Mg3Fe0.9Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 Reaction mixture A was prepared by heating 1370.303 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (1245.730 g) with stirring over 30 min to prepare a clear colorless solution. Reaction mixture B was prepared by heating 257.123 mL of deionized water to 55 °C and then adding Fe(NO3)3·9H2O (285.052 g), Ni(NO3)2·6H20 (911.870 g), Mg(NO3)2·6H2O (603.024 g), and Cr(NO3)3 .9H2O (15.685 g) with stirring. Reaction mixture C was prepared by heating 586.185 mL of deionized water to 65 °C and then adding ammonium heptamolybate (532.896 g) with stirring over 30 min to form a clear colorless solution. Reaction mixture D was prepared by (a) heating 1074.497 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (ii) while the solution was stirring and warming, adding Bi(NO3)3·5H2O (475.357 g) and RbNO3 (23.121 g) respectively. Reaction mixture E was prepared by adding, with stirring, a silica solution (5487.8 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to prepare the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment in air for 3 hours at 290°C, followed by an additional 3 hours at 425°C. The powder was then calcined at 560°C for 3 hours. Example C2 - Ni6Mg1Fe0.7Rb0.1Cr0.05Bi0.83Ce1.67Mo12.85Ox + 50wt% 38.2 nm SiO2 Reaction mixture A was prepared by heating 304.303 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (276.6 g) with stirring over 30 min to form a clear colorless solution. Reaction mixture B was prepared by heating 38.310 mL of deionized water to 55 °C and then adding Fe(NO3)3·9H2O (48.962 g), Ni(NO3)2·6H20 (302.070 g), Mg(NO3)2·6H2O (44.391 g), and Cr(NO3)3.9H2O (11.547 g) with stirring. Reaction mixture C was prepared by heating 127.774 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (116.158 g) with stirring over 30 min to create a clear colorless solution. Reaction mixture D is prepared by (a) heating 317.026 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (b) adding Bi(NO3)3·5H2O (69.706 g) and RbNO3 (8.510 g) respectively while the solution was stirring and heating. Reaction mixture E was prepared by adding, with stirring, a silica solution (1219.5 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to form the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment for 3 hours in air at 290°C, followed by an additional 3 hours at 425°C. The powder was then calcined for 3 hours in air at 560°C. Example 1 and 2 - Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 Reaction mixture A was prepared by heating 1358.961 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (1235.4 g) with stirring over 30 min to form a clear colorless solution. Reaction mixture B was prepared by heating 265.465 mL of deionized water to 55 °C and then adding Fe(NO3)3·9H2O (376.923 g), Ni(NO3)2·6H20 (904.322 g), Mg(NO3)2·6H2O (598.033 g), and Cr(NO3)3.9H2O (15.555 g) with stirring. Reaction mixture C was prepared by heating 581.333 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (488.485 g) with stirring over 30 min to prepare a clear colorless solution. Reaction mixture D was prepared by (a) heating 1065.603 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (b) while the solution was stirring and heating, adding Bi(NO3)3·5H2O (471.422 g) and RbNO3 (22.930 g) in sequence. Reaction mixture E was prepared by adding, with stirring, a silica solution (5487.8 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to form the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment in air for 3 hours at 290°C, followed by an additional 3 hours at 425°C. The powder was then calcined at 560°C for 3 hours. Example 3 and 4 - Ni6Mg1Fe1Rb0.2Cr0.05Bi1Ce1.22Mo12.505Ox + 50wt% 38.2 nm SiO2 Reaction mixture A was prepared by heating 1399.413 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (1272.194 g) with stirring over 30 min to prepare a clear colorless solution. Reaction mixture B was prepared by heating 259.349 mL of deionized water to 55 °C and then adding Fe(NO3)3·9H2O (320.780 g), Ni(NO3)2·6H20 (1385.318 g), Mg(NO3)2·6H2O (203.582 g), and Cr(NO3)3.9H2O (15.886 g) with stirring. Reaction mixture C was prepared by heating 528.924 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (480.840 g) with stirring over 30 min to create a clear colorless solution. Reaction mixture D is prepared by (a) heating 1062.136 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (b) adding Bi(NO3)3·5H2O (385.155 g) and RbNO3 (23.417 g) respectively while the solution was stirring and heating. Reaction mixture E was prepared by adding, with stirring, a silica solution (5263.2 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to form the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment in air for 3 hours at 290°C, followed by an additional 3 hours at 425°C. The powder was then calcined at 560°C for 3 hours. Example 5 - Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.730Ox Reaction mixture A was prepared by heating 150.66 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (60.136 g) with stirring over 30 min to create a clear colorless solution. Reaction mixture B was prepared by heating 29.93 mL of deionized water to 55 °C and then adding Fe(NO3)3·9H2O (42.2625 g), Ni(NO3)2·6H20 (101.42 g), Mg(NO3)2·6H2O (67.0604 g), and Cr(NO3)3·9H2O (1.7441 g) with stirring. Reaction mixture C was prepared by heating 71.75 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (3332.59 g) with stirring over 30 min to prepare a clear colorless solution. Reaction mixture D is prepared by (a) heating 119.53 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (b) adding Bi(NO3)3·5H2O (52.8606 g) and RbNO3 (2.7027 g) respectively while the solution was stirring and heating. Reaction mixture E was prepared by adding, with stirring, a silica solution (609.76 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to form the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment in air for 3 hours at 290°C, followed by a further 3 hours at 425°C. The powder was then calcined at 560°C for 3 hours. Example 6 - Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.130Ox + 50wt% 38.2 nm SiO2 Reaction mixture A was prepared by heating 144.67 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (131.32 g) with stirring over 30 min to prepare a clear colorless solution. Reaction mixture B was prepared by heating 30.87 mL of deionized water to 55 °C and then adding iron Fe(NO3)3·9H2O (43.5883 g), Ni(NO3)2·6H20 (104.57 g), Mg(NO3)2·6H2O (69.1397 g) and Cr(NO3)3.9H2O (1.7983 g) with stirring. Reaction mixture C was prepared by heating 12.74 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (61.1793 g) with stirring over 30 min to form a clear colorless solution. Reaction mixture D is prepared by (a) heating 123.30 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (b) adding Bi(NO3)3·5H2O (54.5021 g) and RbNO3 (2.7847 g) respectively while the solution was stirring and heating. Reaction mixture E was prepared by adding, with stirring, a silica solution (609.80 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to form the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment in air for 3 hours at 290°C, followed by a further 3 hours at 425°C. The powder was then calcined at 560°C for 3 hours. Example 7 - Ni4Mg3Fe1.2Rb0.192Cr0.05Bi1.0Sm0.1Ce1.5Mo12.996Ox +50wt% 38.2 nm SiO2 Reaction mixture A was prepared by heating 152.49 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (139.06 g) with stirring over 30 min to prepare a clear colorless solution. Reaction mixture B was prepared by heating 28.35 mL of deionized water to 55 °C and then adding Fe(NO3)3·9H2O (41.73229 g), Ni(NO3)2·6H20 (100.16 g), Mg(NO3)2·6H2O (66.2090 g) and Cr(NO3)3·9H2O (1.7272 g) with stirring. Reaction mixture C was prepared by heating 70.69 mL of deionized water to 65 °C and then adding ammonium heptamolybdate (58.4395 g) with stirring over 30 min to create a clear colorless solution. Reaction mixture D is prepared by (a) heating 141.57 g of a 50 wt% aqueous solution of (NH4)2Ce(NO3)6 to 55 °C, (b) adding Bi(NO3)3·5H2O (41.7512 g), RbNO3 (2.4389 g), and Sm(NO3)3·6H2O (3.8270 g) in order while the solution was stirring and heating. Reaction mixture E was prepared by adding, with stirring, a silica solution (609.76 g, 41 wt% silica) to reaction mixture A, followed by the addition of reaction mixture B. Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (this mixture was from the precipitation solution). Stirring of the precipitation solution was continued for 15 minutes while maintaining the temperature in the range of 50-55 °C. Reaction mixture F was then added to reaction mixture E to form the final catalyst precursor solution. The catalyst precursor solution was allowed to stir for one hour while cooling to approximately 40°C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The solution was then dried in a spray dryer at an inlet / outlet temperature of 325 / 140°C. The resulting powder was degassed by heat treatment in air for 3 hours at 290°C, followed by a further 3 hours at 425°C. The powder was then calcined at 560°C for 3 hours. Example 8 The sample catalyst was prepared using the same preparation as in Example 7, except that 0.094 g of solid K2MoO4 crystals was added to the finished catalyst. Example 9 This example is a continuation of the catalyst test of Example 8. After 382 hours on stream, 0.144 g of MoO3 was added to the catalyst of Example 8 and the test continued for the detoxification of propylene to acrylonitrile. Catalyst test All catalysts were tested in a bench-scale reactor for the detoxification of propylene to acrylonitrile using 30 g of catalyst. All experiments were conducted in a 40 cc fluidized bed reactor. Propylene was fed into the reactor at the rates shown in Table 1 and Table 3, between 0.080 and 0.100 WWH (i.e., weight of propylene / weight of catalyst per hour). The pressure inside the reactor was maintained at 10 psig. The reaction temperature was 430°C. Samples of the reaction products were collected after several days of testing (between about 140 and about 190 hours on-stream). The reactor effluent was collected in bubble-type scrubbers containing cold hydrochloric acid solution. The off-gas was measured with a soap film, and the off-gas composition was separated at the end of the run by means of a gas chromatograph equipped with a column gas analyzer. At the end of the recovery period, the total scrubber liquid was diluted to approximately 200 g with distilled water. A weighted amount of 2-butanone was used as an internal standard in a 50 g dilution ratio. A 2 μL sample was analyzed in a GC equipped with a flame ionization detector and a Carbowax column.The NH3 content was determined by titrating the excess HCl with NaOH solution. The propylene conversion and acrylonitrile yield for the tested catalysts are as shown in Tables 1 and 3. HCN was titrated using AgNO3 solution after addition of caustic iodide. Table 1 Ex. No. Catalyst Composition WWH T°C HOS % C= Conv. % AN Yield % HCN Yield % ACN Yield α C1 Ni4Mg3Fe0.9Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 0.080 430.0 120.6 98.1 84.6 3.6 2.1 100.5 C2 Ni6Mg1Fe0.7Rb0.1Cr0.05Bi0.83Ce1.67Mo12.85Ox + 50wt% 38.2 nm SiO2 0.100 430.0 347.1 99.2 82.2 5.0 2.0 101.0 1 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 0.090 430.0 144.8 99.5 84.3 5.1 2.0 103.1 2 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 0.090 430.0 504.0 99.1 83.4 6.3 1.7 105.8 3 Ni6Mg1Fe1Rb0.2Cr0.05Bi1Ce1.22Mo12.505Ox + 50wt% 38.2 nm SiO2 0.090 430.0 319.4 99.2 83.7 5.0 2.1 102.7 4 Ni6Mg1Fe1Rb0.2Cr0.05Bi1Ce1.22Mo12.505Ox + 50wt% 38.2 nm SiO2 0.085 440.0 990.0 98.5 82.9 5.8 2.0 104.9 5 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.730Ox + 50wt 38.2 nm SiO2 0.090 435.0 190.3 98.3 82.6 6.4 1.6 105.8 6 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.130Ox + 50wt% 38.2 nm SiO2 0.090 430.0 290.5 98.2 82.3 6.1 2.1 105.7 7 Ni4Mg3Fe1.2Rb0.192Cr0.05Bi1.0Sm0.1Ce1.5Mo12.996Ox + 50wt% 38.2 nm SiO2 0.100 435.0 237 98.9 82.8 5.7 1.9 103.9. Table 2 Ex. No. Catalyst Composition b / (a+h) (a+h) / d m-[(3a+2b+c+2d+3h+3n) / 2] C1 Ni4Mg3Fe0.9Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 0.36 0.357 1.025 C2 Ni6Mg1Fe0.7Rb0.1Cr0.05Bi0.83Ce1.67Mo12.85Ox + 50wt% 38.2 nm SiO2 0.28 0.375 1.275 1 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 0.48 0.375 0.725 2 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.85Ox + 50wt% 38.2 nm SiO2 0.48 0.375 0.725 3 Ni6Mg1Fe1Rb0.2Cr0.05Bi1Ce1.22Mo12.505Ox + 50wt% 38.2 nm SiO2 0.45 0.317 1.0 4 Ni6Mg1Fe1Rb0.2Cr0.05Bi1Ce1.22Mo12.505Ox + 50wt% 38.2 nm SiO2 0.45 0.317 1.0 5 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.730Ox + 50wt 38.2 nm SiO2 0.48 0.375 0.6 6 Ni4Mg3Fe1.2Rb0.2Cr0.05Bi1.25Ce1.25Mo12.130Ox + 50wt% 38.2 nm SiO2 0.48 0.375 0 7 Ni4Mg3Fe1.2Rb0.192Cr0.05Bi1.0Sm0.1Ce1.5Mo12.996Ox + 50wt% 38.2 nm SiO2 0.48 0.375 0.875 Table 3 Combined composition of molybdate oxide and molybdenum oxide Ex. No. Catalyst Composition WWH T°C HOS % C= Conv. % AN Yield % HCN Yield % ACN Yield α 7 Ni4Mg3Fe1.2Rb0.192Cr0.05Bi1.0Sm0.1Ce1.5Mo12.996Ox + 50wt% 38.2 nm SiO2 0.100 435.0 237 98.9 82.8 5.7 1.9 103.9 8 Example 8 + 0.144g MoO3 added after 382 hours on stream 0.100 430.0 2.5 99.1 84.0 5.2 2.3 103.9 Notes from Tables 1, 2 and 3 (are applicable): 1.WWH is the weight of propylene per weight of catalyst per hour in feed. 2. T°C is the reactor temperature in Celsius. 3. HOS is hours on stream. 4. %C3=Conv or %PC is the propylene conversion (i.e., mole percent of the percentage amount per conversion of propylene to all products). 5. Yield % AN is the percentage yield of acrylonitrile. 6. Yield % AN is the percentage yield of acrylonitrile. 7. Aceto % yield is the acetonitrile yield. 8.  is calculated as follows:  = [(%AN + (3 × %HCN) + (1.5 × %ACN)) ÷ %PC] × 100 9. b / (a+h) is the ratio of the composition of iron atoms to bismuth atoms plus cerium atoms. 10. (a+h) / d) is the ratio in the composition of bismuth atoms plus cerium atoms to atoms of the D elements (i.e. nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium). 11. For catalysts according to the formula given in this article, m - [(3a + 2b + c + 2d + 3h + 3n) / 2]" ", the numerical value is obtained by subtracting the number of molybdenum atoms (subset "m" of the formula). The sum [(3 × number of bismuth atoms). 0 + (2 number of iron atoms) + (number of lithium, sodium, potassium, rubidium and cesium atoms) + (2 × number of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium atoms) + (3 × number of cerium atoms) + (3 × number of chromium atoms)] divided by 2. The present invention is directed to a novel and improved mixed metal oxide catalyst for the detoxification of propylene and / or isobutylene. The improved catalyst provides for a higher overall conversion of propylene and / or isobutylene to hydrogen cyanide while maintaining the level of acrylonitrile and / or methacrylonitrile production at the same level as prior art catalysts. The data in Tables 1 and 2 clearly demonstrate the benefits of the present invention. Examples 1 to 6 have values ​​of "b / (a+h)" and "(a+h) / d" within the claimed invention range (i.e. 0.4 <b (a ​​+ h) و 0.3 ≤(a + h ) d عملکرد سیانید هیدروژن بیشتری (تقریباً 1 تا 3٪ بالاتر) نسبت به کاتالیزورهای c1 از طریق c2 که خارج یک یا هر دو "(a b" d" نشان داده شده دارند، می دهیم.The data in Table 3 clearly demonstrate the experience of this invention. In particular, for propylene to acrylonitrile with hydrogen cyanide produced as a co-product when combining the inventive catalyst (i.e., the composition of Example 7) with an alkaline molybdate (i.e., the mixture of Example 8) there will be a further increase in HCN yield and a further increase in nitrogen efficiency as shown by the increase in the α factor. As shown in Example 9, this effect may be reversed. Example 9 shows that the catalyst mixture of Example 8 can be returned to a state that provides high acrylonitrile yields by the addition of molybdenum oxide (with Example 7) (i.e., in Example 9 the catalyst has returned to the performance of the base composition as shown in Example 7). While the foregoing description and experiments are typical of the practice of the instant invention, it is obvious that many alternatives, modifications and variations consistent with this description will be apparent to those skilled in the art. Accordingly, it is intended that all such alternatives, modifications and variations be embraced and fall within the spirit and scope of the appended claims.

Claims

1. A catalytic composition comprising a complex of metal oxides wherein the relative ratios of the listed elements in said catalyst composition are represented by the following formula: Mom Bia Feb Ac Dd Ee Ff Gg Ceh Crn Qq Ox wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium; D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium; E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium; F is at least one element selected from the group consisting of lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, lead and germanium; G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury; Q is at least one of samarium, praseodymium and neodymium; and a, b, c, d, e, f, g, h, n, m and x are, respectively, the atomic ratios of bismuth (Bi), iron (Fe), A, D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo) and oxygen (O), relative to “m” atoms of molybdenum (Mo), wherein a is 0.05 to 7, b is 0.1 to 7, c is 0 to 5, d is 0.1 to 12, e is 0 to 5, f is 0 to 5, g is 0 to 0.2, h is 0.01 to 5, m is 10 to15, n is 0 to 5, q is 0 to 2.476, and x is the number of oxygen atoms required to satisfy the valence requirements of the other component elements present; and wherein 0.4< b / (a+h) and 0.3 ≤ (a+h) / d; and wherein 0 ≤ m − (3a+2b+c+2d+3h+3n) / 2 ≤ 1.

0.

2. The catalyst composition of claim 1, wherein 0.3 ≤ (a+h) / d ≤ 1.

3. The catalyst composition of claim 1, wherein 0.45 ≤ (a+h) / d ≤ 1.

4. The catalyst composition of claim 1, wherein 0.8 ≤ h / b ≤ 5.

5. The catalyst composition of claim 1, wherein 0.5 ≤ a / h < 1.

5.

6. The catalyst composition of claim 1, wherein 0 ≤ q / (a+h+q) and q / (a+h+q) < 0.16 .

7. The catalyst composition of claim 1 wherein D is nickel.

8. The catalyst composition of claim 1, additionally comprising at least one alkali molybdate compound represented by the formula: A2 Moz O4+3(z-1) wherein A is Rb, Li, Na, K, Cs, or a mixture thereof. z is from 1 to about 8.

9. The catalyst composition of claim 8, wherein the alkali molybdate compound comprises a support selected from the group consiting of silica, alumina, zirconia, titania, or mixtures therof, and wherein the support comprises between 1 wt% to 99 wt% of the alkali molybdate compound and support combination.10 The catalyst composition of claim 8, wherein the catalyst composition comprises between of 0.01 wt% to about 10 wt% of the alkali molybdate compound relative to the total weight of said catalyst composition.11 The catalyst composition of claim 1, wherein the catalytic composition when utilized as a catalyst for the production of acrylonitrile, acetonitrile and hydrogen cyanide in a process comprising contacting at an elevated temperature, propylene, ammonia and oxygen in the vapor phase in the presence of a catalyst, the relative yields of acrylonitrile, acetonitrile and hydrogen cyanide from said process are defined by the following:  = [(%AN + (3 × %HCN) + (1.5 × %ACN)) ÷ %PC] × 100 wherein %AN is the Acrylonitrile Yield and %AN > 82, %HCN is the Hydrogen Cyanide Yield and %HCN > 5 %ACN is the Acetonitrile Yield, %PC is the Propylene Conversion, and  is greater than 102.5.

12. A process for the conversion of an olefin selected from the group consisting of propylene, isobutylene and mixtures thereof, to acrylonitrile, methacrylonitrile, and mixtures thereof, with hydrogen cyanide produced as a co-product, by reacting in the vapor phase at an elevated temperature and pressure said olefin with a molecular oxygen containing gas and ammonia in the presence of a catalyst wherein the relative ratios of the listed elements in said catalyst are represented by the following formula: Mom Bia Feb Ac Dd Ee Ff Gg Ceh Crn Qq Ox wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium; D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium; E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium; F is at least one element selected from the group consisting of lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, lead and germanium; G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury; Q is at least one of samarium, praseodymium and neodymium and a, b, c, d, e, f, g, h, n, m and x are, respectively, the atomic ratios of bismuth (Bi), iron (Fe), A, D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo) and oxygen (O), relative to “m” atoms of molybdenum (Mo), wherein a is 0.05 to 7, b is 0.1 to 7, c is 0 to 5, d is 0.1 to 12, e is 0 to 5, f is 0 to 5, g is 0 to 0.2, h is 0.01 to 5, m is 10 to 15, n is from 0 to 5, q is 0 to 2.476 and x is the number of oxygen atoms required to satisfy the valence requirements of the other component elements present; and wherein 0.4< b / (a+h) and 0.3 ≤ (a+h) / d; and wherein 0 ≤ m − (3a+2b+c+2d+3h+3n) / 2 ≤ 1.0.13 The process of claim 12, wherein the yield of hydrogen cyanide is increased relative to the amount of acrylonitrile and methacrylonitrile produced in the process by the addition to the catalyst of at least one alkali molybdate compound represented by the formula: A2 Moz O4+3(z-1) wherein A is Rb, Li, Na, K, Cs, or a mixture thereof, and z is from 1 to about 8.

14. The process of claim 13, wherein the catalyst comprises between of 0.01 wt% to about 10 wt% of the alkali molybdate compound relative to the total weight of said catalyst.

15. The process of claim 12, wherein the yield of acrylonitrile and methacrylonitrile is increased relative to the amount of hydrogen cyanide produced in the process by the addition to the catalyst of a molybdenum oxide compound selected from the group consisting of MoO3 , ammonium molybdate, ammonium heptamolybdate, ammonium dimolybdate and mixtures thereof.

16. The process of claim 15, wherein t he amount of said molybdenum oxide compound added to the catalyst is in the range of 0.01 wt% to about 10 wt%, relative to the weight of said catalyst. 17 The process of claim 12, wherein 0.3 ≤ (a+h) / d ≤ 1 in the catalyst.

18. The process of claim 12, wherein 0.45 ≤ (a+h) / d ≤ 1 in the catalyst.

19. The process of claim 12, wherein 0.8 ≤ h / b ≤ 5 in the catalyst.

20. The process of claim 12, wherein 0.5 ≤ a / h < 1.5 in the catalyst.

21. The process of claim 12, wherein 0 ≤ q / (a+h+q) and q / (a+h+q) < 0.16 in the catalyst.

22. The process of claim 12, wherein D is nickel in the catalyst .

23. The process of claim 12, wherein said process is defined by the following:  = [(%AN + (3 × %HCN) + (1.5 × %ACN)) ÷ %PC] × 100 wherein %AN is the Acrylonitrile Yield and %AN > 82, %HCN is the Hydrogen Cyanide Yield and %HCN > 5 %ACN is the Acetonitrile Yield, %PC is the Propylene Conversion, and  is greater than 102.5.