Abstract: Disclosed are a process for producing an unsaturated aldehyde and an unsaturated carboxylic acid which comprises subjecting propylene, isobutylene or tertiary butanol to gas phase catalytic oxidation with molecular oxygen in the presence of (i) a catalyst comprising composite oxide of the formula Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g O.sub.x and (ii) a molybdenum oxide which in itself is substantially inert to the gas phase catalytic oxidation; a process for reusing the catalyst deteriorated due to the gas phase catalytic oxidation after mixing it with the molybdenum oxide; and a method of regenerating the deteriorated catalyst by mixing it with the molybdenum oxide.

Abstract: Nitrobenzenes are prepared by nitrating benzenes in vapor phase using nitric acid as a nitrating agent and under continuous or intermittent feeding of sulfuric acid as a catalyst in the presence of a catalyst comprising sulfuric acid supported on a carrier or in the presence of only a carrier. This process can provide very high and prolonged nitration activity.

Abstract: Nitrobenzenes are prepared by nitrating benzenes in a vapor phase with dilute or concentrated nitric acid wherein the following (A) or (B) is used as a catalyst:(A) acidic sheet clay minerals ion-exchanged with polyvalent metals, or(B) acidic composite oxides comprising oxides of metals belonging to Group IVA of the Mendeleefs' periodic table and tungsten oxide, molybdenum oxide, niobium oxide or zinc oxide.These catalysts have high catalyst activity and selectivity for vapor phase nitration reaction of benzenes with nitric acid and besides the activity is retained for a long time.

Abstract: In the production of methacrolein by vapor phase catalytic oxidation of isobutylene and/or t-butyl alcohol, an improved process for suppressing the amount of acetone to be by-produced which comprises contacting a gaseous mixture comprising isobutylene or t-butyl alcohol, molecular oxygen and steam with a metal oxide catalyst composition comprising molybdenum and bismuth as the essential metal components, the amount of steam in the gaseous mixture being kept to be not more than 4 mol per mol of isobutylene or not more than 3 mol per mol of t-butyl alcohol.

Abstract: A process for production of acrylic acid by the gas phase catalytic oxidation of acrolein with molecular oxygen in the presence of a catalyst, characterized in that the catalyst is a metal oxide catalyst containing as the metal elements Mo, V, Cu and X in a ratio of 12 : 0.1-16 : 0.1-8 : 0.01-12 as the number of atoms (wherein X represents at least one element selected from the group consisting of Fe, Co, Ni and Mg), whereby acrylic acid can be produced at a greatly lowered reaction temperature in a markedly increased yield with an improved perpass yield.

Abstract: A catalytic process for the preparation of acrolein by the vapor phase oxidation of propylene which comprises contacting propylene and oxygen with a catalyst composition comprising a catalyst system of the formula:Mo.sub.a Bi.sub.b Fe.sub.c X.sub.d Ni.sub.e Tl.sub.f P.sub.g O.sub.hwherein X is one or more of Mg, Mn and Co and a, b, c, d, e, f, g and h represent, respectively, the number of atoms wherein a is 12, b is 0.1 to 5, c is 0.1 to 5, d is 0 to 12, e is 0.1 to 12, f is 1 or less but not 0, g is 0 to 5 and h depends on the number of the other atoms and is usually from 36 to 89. Acrolein is produced with the use of said catalyst in a high selectivity and an excellent yield per each pass even at a large space velocity.

Abstract: A process for the preparation of acrolein by the vapor phase catalytic oxidation of propylene which comprises contacting propylene and oxygen with a catalyst composition comprising a catalyst system of the formula:Mo.sub.a Bi.sub.b Fe.sub.c Ni.sub.d Tl.sub.e P.sub.f X.sub.g Y.sub.h O.sub.iWherein X is one or more of Mg, Mn and Co, Y is one or more of Cu, Ca, Sr, Zn, Cd, Sn and Pb and a, b, c, d, e, f, g, h and i represent respectively the number of atoms and, when a is 12, b is 0.1 to 5, c is 0.1 to 12, d is 0.1 to 12, e is 1 or less but not 0, f is 0 to 5, g is 0 to 12, h is 0.1 to 12 and i is a number determined by the valence requirements of the other atoms present and from 36.5 to 95.8, provided that b plus c is from 0.2 to 12.5 and d plus g plus h is from 0.2 to 27. The process can provide acrolein in a high selectivity and an excellent single pass yield even at a large space velocity of the propylene feed.

Abstract: A catalytic process for the preparation of acrolein by the vapor phase oxidation of propylene which comprises contacting propylene and oxygen with a catalyst composition comprising a catalyst system of the formula:Mo.sub.a Bi.sub.b Fe.sub.c Ni.sub.d Tl.sub.e P.sub.f X.sub.g Y.sub.h O.sub.i wherein X is one or more of Mg, Mn and Co, Y is one or more of Cu, Ca, Sr, Zn, Cd, Sn and Pb and a, b, c, d, e, f, g, h and i represent respectively the number of atoms, provided that, when a is 12, b is 0.1 to 5, c is 0.1 to 12, d is 0.1 to 12, e is 1 or less but not 0, f is 0 to 5, g is 0 to 12, h is 0.1 to 12 and i is from 36 to 112. By such a process, acrolein is produced in a high selectivity and an excellent yield per each pass even at a large space velocity.