The invention discloses a catalyst for selectively oxidizing methacrylaldehyde to prepare methacrylic acid and preparation and application methods thereof. The catalyst for selectively oxidizing the methacrylaldehyde to prepare the methacrylic acid is composed of PaMobVcXxYyZz1HhOg1-Zz2Og2, wherein X is a combination of at least two from sodium, potassium, rubidium and cesium, Y is a mixture of one or at least two from calcium, magnesium, chromium, manganese, iron, cobalt, copper, nickel, zinc, aluminum, silicon, germanium, antimony, bismuth, lanthanum or cerium, and Z comprises titanium and/or zirconium. Compared with traditional phosphovanadomolybdate catalysts. The catalyst for selectively oxidizing the methacrylaldehyde to prepare the methacrylic acid can be higher in activity when applied to selectively oxidizing the methacrylaldehyde to prepare the methacrylic acid, and during the catalytic process, when the methacrylaldehyde converting rate is 90%, and the selectivity to the methacrylic acid can reach up to 93%, so that the catalyst for selectively oxidizing the methacrylaldehyde to prepare the methacrylic acid can meet the demands of practical industrial production.

Catalyst for selectively oxidizing methacrylaldehyde to prepare methacrylic acid and preparation and application methods thereof

The invention concerns a compound comprising a combination of two crystal phases. The first crystal phase corresponds to the formula: A a E b V c Mo d P e O f H g wherein A is an alkali-metal; E is Te, Sb or Bi; and 0≦a≦3, 0<b≦3, 0≦c≦3, 0<d≦13, 0<e≦2, 0≦g≦3. The second crystal phase corresponds to the formula Z g Mo h X i O j wherein: Z is selected among trivalent rare earths; X is selected among the elements V, Ga, Fe, Bi, Ce, Ti, Sb, Mn, Zn, Te; and 0<g≦3, 0≦h≦3, 0≦i≦1. The indices f and j represent the number of oxygen atoms required for satisfying the relative valency and atomic proportions of the elements present. The invention also concerns the method for preparing said compound, and its use in particular as catalyst for oxidizing alkanes.

Preparing a compound comprising a combination of two crystal phases

L'invention concerne un compose comprenant l'association de deux phases cristallines. La premiere phase cristalline repond a la formule : AaEbVcMOdPeOfHg dans laquelle A est un metal alcalin, E est Te, Sb ou Bi, et 0 3, 0 13, 0 2, 0 3, 0<=h<=3, O<=i<=1. Les indices f et j representent le nombre d'atomes d'oxygene necessaire pour satisfaire la valence et les proportions atomiques relatives des elements presents.L'invention a egalement pour objet le procede de preparation de ce compose, ainsi que son utilisation notamment en tant que catalyseur pour l'oxydation d'alcanes.

Philippe Lacorre

Papers

Preparing a compound comprising a combination of two crystal phases

Preparation d'un compose comprenant l'association de deux phases cristallines