Abstract: Olefins are hydrated to the corresponding alcohols in the presence of at least one crystalline alumino-silicate selected from offretite, ferrierite and erionite. The offretite, ferrierite and erionite are preferably characterized by X-ray diffraction patterns shown in Tables 1 and 7; Tables 2, 8 and 9; and Table 3, respectively. At least a part of the exchangeable cations in the offretite, ferrierite and erionite may be exchanged with at least one cation selected from a hydrogen ion, an alkaline earth metal ion and a rare earth metal ion. Furthermore, at least a part of the exchangeable cations in the erionite may be exchanged with an ammonium ion and/or an alkali metal ion.

Abstract: A process for producing methacrylic acid by the vapor phase catalytic oxidation of methacrolein with molecular oxygen or a molecular oxygen-containing gas comprises using a catalyst of multi-elemental complex oxide having the formulaMo.sub.a P.sub.b As.sub.c Cu.sub.d Cr.sub.e X.sub.f O.sub.gwherein X represents at least one of element of Ce, Nd, W and Fe; a, b, c, d, e, f and g respectively represent atomic ratios and a=12, b=0.5 to 3.0, c=0.01 to 1.2, d=0.01 to 2.0, e=0.05 to 2.0 and f=0 to 1.0; and g is decided on the valences of the other components such as usually 37 to 58 which is prepared with or without a reduction using a dibasic carboxylic acid, an oxycarboxylic acid, mannitol or pyrogallol.

Abstract: Methacrolein is produced by a vapor phase oxidation of isobutylene or tertiary butanol in the presence of a complex oxide catalyst having the formulaMo.sub.a Co.sub.b Fe.sub.c Bi.sub.d Tl.sub.e X.sub.f Y.sub.g Z.sub.h O.sub.iwherein X represents V and/or Nb; Y represents La and/or Ce; and Z represents Cs and/or Te and a, b, c, d, e, f, g, h and i represent atomic ratios wherein a=12; b=3 to 15; c=0.4 to 5; d=0.4 to 5; e=0.01 to 2; f=0.01 to 2; g=0 to 2; h=0 to 2; and i is determined by the valences of the non-oxygen components of the catalyst and is usually in a range of 40 to 79.

Abstract: A process for producing methacrylic acid by the vapor phase catalytic oxidation of methacrolein with molecular oxygen or a molecular oxygen-containing gas comprises using a catalyst of multi-elemental complex oxide having the formulaMo.sub.a P.sub.b As.sub.c V.sub.d Cu.sub.e Ce.sub.f Cr.sub.g O.sub.hwherein a, b, c, d, e, f, g and h respectively represent atomic ratios and a=12, b=0.5 to 3.0, c=0.01 to 1.2, d=0.01 to 2.0, e=0.01 to 2.0, f=0.01 to 1.2, g=0 to 2.0; and h is decided on the valences of the other components such as usually 37 to 60 which is prepared with or without a reduction using a dibasic carboxylic acid, an oxycarboxylic acid, mannitol or pyrogallol.

Abstract: Methacrylic acid is produced by the vapor phase oxidation of methacrolein in the presence of a complex oxide catalyst having the formula:Mo.sub.a V.sub.b P.sub.c Ce.sub.d Cu.sub.e X.sub.f O.sub.gwherein X represents at least one of the elements selected from the group of Mn, Fe, Co, Sn and Te and a, b, c, d, e, f and g represent atomic ratios wherein a=12; b=0.01 to 2; c=0.1 to 3; d=0.01 to 2; e=0.01 to 2; f=0 to 2 and g is determined by the valences of the non-oxygen components of the catalyst and is usually in a range of 38 to 50. The catalyst can be optionally reduced by subjecting the metal oxide mixture to at least one reducing organic material selected from the group consisting of dibasic carboxylic acids, oxycarboxylic acids, and polyols.