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.