Abstract: At least one olefinic hydrocarbon of 3 to 4 carbon atoms is oxidized catalytically in the gas phase in the presence of molecular oxygen at 200.degree.-450.degree. C. to produce the corresponding aldehyde and acid over a calcined catalyst of the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h O.sub.i wherein X is at least one alkali metal selected from the group consisting of potassium, rubidium and cesium; Y is at least one metal selected from the group consisting of cobalt, uranium, germanium, tungsten and titanium; a to h are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.2 to 12, e=0.2 to 12, f=0 to 20, g=0.01 to 4 and h=0 to 6; and i is determined according to the oxidation states of the metal atoms in the catalyst.

Abstract: At least one compound from the group of unsaturated hydrocarbons of three to four carbon atoms and t-butyl alcohol is oxidized catalytically in the gas phase in the presence of molecular oxygen at 200.degree.-450.degree. C to produce the corresponding aldehyde or acid over a calcined catalyst of the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h O.sub.i wherein X is at least one of potassium, rubidium or cesium, Y is at least one of cobalt, uranium, germanium, tungsten or titanium, a to h are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.2 to 12, e=0.2 to 12, f=0 to 20, g=0.01 to 4 and h=0 to 6 and i is a value determined by the oxidation state of the metal atoms in the catalyst.An embodiment of the calcined catalyst of the invention has the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h Z.sub.j O.sub.i wherein X and y are as defined above and Z is palladium and a to j are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.

Abstract: Acrylic acid or methacrylic acid is prepared by vapor-phase catalytic oxidation of acrolein or methacrolein, with molecular oxygen at a temperature of from 240.degree. to 450.degree. C in the presence of a catalyst represented by the formula:Mo.sub.12 P.sub.a Mg.sub.b Q.sub.b.sub.' R.sub.c T.sub.d O.sub.ewherein Mo is molybdenum, P is phosphorus, Mg magnesium, O is oxygen, Q is at least one of calcium, strontium, and barium, R is at least one of potassium, rubidium, cesium and thallium, T is at least one of vanadium, tungsten and nickel, and a, b, c, d, and e are atomic ratios of the respective elements, where a=0.5-6, b=0.2-6, b+b'= 0.2-6, b' ranges from 0 to a value determined by the magnesium content of the catalyst and the limits of b+b', c=0.2-6, d=0-6, and e is a value dependent upon the oxidation state of the catalyst.

Abstract: The gas phase catalytic oxidation of an unsaturated aldehyde with molecular oxygen at 240.degree. to 390.degree. C to give the corresponding unsaturated carboxylic acid is conducted in the presence of a catalyst represented by the following formula:P.sub.a Mo.sub.b As.sub.c (NH.sub.4).sub.d X.sub.e Y.sub.f O.sub.gwherein a, b, c, e, f and g represent the atomic ratio of each component and a is 0.03 to 0.2, b is 1, c is 0.015 to 0.15, e is 0.003 to 1, f is 0 to 0.17, g is a value determined by the valencies of the elements present in the catalyst, and d designates the number of ammonium groups which are within the range of 0.01 to 0.3, and wherein X is at least one metal selected from the group consisting of vanadium, tungsten, copper, iron, manganese and tin, and Y is at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium.

Abstract: Methacrolein is produced by catalytically oxidizing t-butyl alcohol with oxygen by using a catalyst system of MoSbBiFeNi-alkali. Propylene or isobutylene can also be catalytically oxidized with the same catalyst system to produce acrolein or methacrolein. Methacrolein and 1,3-butadiene can simultaneously be produced by catalytically oxidizing a mixture of isobutylene and n-butene with the same catalyst.

Abstract: Oxidation of tert.-butyl alcohol is accomplished by contacting said alcohol with a tungsten-molybdenum-tellurium-nickel catalyst in the vapor phase at an elevated temperature in the presence of oxygen, in order to produce methacrolein and methacrylic acid. The catalyst desirably contains phosphorus and/or antimony in addition to the elements mentioned above.