Catalyst and method for partially oxidizing hydrocarbons

A catalyst for the partial oxidation of hydrocarbons in the gas phase, comprising a multimetal oxide of the general formula (I)

• AgaMobVcMdOe*f H2O (I)
• in which
• M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, B, Al, Ga, In, Si, Sn, Pb, P, Sb, Bi, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Au, Zn, Cd, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, U,
• a has a value of 0.5 to 1.5,
• b has a value of 0.5 to 1.5,
• c has a value of 0.5 to 1.5,
• a+b+c has the value of 3,
• d has a value of less than 1,
• e is a number which is determined by the valency and frequency of the elements in the formula I other than oxygen,
• f has a value of 0 to 20,
• which is present in a crystal structure whose powder x-ray diffractogram is characterized by reflections at at least 5 interplanar spacings selected from d=4.53, 3.38, 3.32, 3.23, 2.88, 2.57, 2.39, 2.26, 1.83, 1.77 Å (±0.04 Å).

A process for preparing a multimetal oxide of the general formula (I)

• AgaMobVcMdOe.f H2O (I)
• in which
• M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, B, Al, Ga, In, Si, Sn, Pb, P, Sb, Bi, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Au, Zn, Cd, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, U,
• a has a value of 0.5 to 1.5,
• b has a value of 0.5 to 1.5,
• c has a value of 0.5 to 1.5,
• a+b+c has the value of 3,
• d has a value of less than 1,
• e is a number which is determined by the valency and frequency of the elements in the formula I other than oxygen,
• f has a value of 0 to 20,
• which comprises mixing at least one silver source, at least one molybdenum source, at least one vanadium source and optionally a source of the element M in wet form, the mixture is dried and the solid obtained is treated thermally.