Hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof are dehydrated using a catalyst and a method to produce bio-acrylic acid, acrylic acid derivatives, or mixtures thereof. A method to produce the dehydration catalyst is also provided.

The present invention relates to the use of molybdenum and vanadium mixed oxides, optionally iron doped, as catalysts for the oxidation of unsaturated alcohols, in particular allyl alcohol, and also to a process for the production of unsaturated carboxylic acids, in particular acrylic acid, in the gas phase, in the presence of such a catalyst.

The present invention relates to the use of molybdenum and vanadium mixed oxides, optionally iron doped, as catalysts for the oxidation of unsaturated alcohols, in particular allyl alcohol, and also to a process for the production of unsaturated carboxylic acids, in particular acrylic acid, in the gas phase, in the presence of such a catalyst.

The invention relates to a catalyst that comprises a mesoporous oxide matrix, with said matrix comprising at least one oxide of an element X that is selected from among silicon and titanium, taken by itself or in a mixture, with said catalyst comprising at least the tantalum element and the niobium element, with the tantalum mass representing between 0.1 to 30% by weight of the mass of the mesoporous oxide matrix, the niobium mass representing between 0.02 to 6% by weight of the mass of the mesoporous oxide matrix, the content by mass of the tantalum element being greater than or equal to the content by mass of the niobium element. The invention also relates to the use of this catalyst in a method for the production of 1,3-butadiene from a feedstock that comprises at least ethanol.

The invention relates to a catalyst that comprises a mesoporous oxide matrix, with said matrix comprising at least one oxide of an element X that is selected from among silicon and titanium, taken by itself or in a mixture, with said catalyst comprising at least the tantalum element and the niobium element, with the tantalum mass representing between 0.1 to 30% by weight of the mass of the mesoporous oxide matrix, the niobium mass representing between 0.02 to 6% by weight of the mass of the mesoporous oxide matrix, the content by mass of the tantalum element being greater than or equal to the content by mass of the niobium element. The invention also relates to the use of this catalyst in a method for the production of 1,3-butadiene from a feedstock that comprises at least ethanol.

The invention relates to a catalyst that comprises at least the tantalum element, at least an aldolizing element and at least a mesoporous oxide matrix, with the tantalum mass being between 0.1 and 30% of the mesoporous oxide matrix mass, the mass of the at least one aldolizing element being between 0.02 and 4% of the mesoporous oxide matrix mass, and use thereof.

The invention relates to a catalyst that comprises at least the tantalum element, at least an aldolizing element and at least a mesoporous oxide matrix, with the tantalum mass being between 0.1 and 30% of the mesoporous oxide matrix mass, the mass of the at least one aldolizing element being between 0.02 and 4% of the mesoporous oxide matrix mass, and use thereof.

A mesoporous mixed oxide catalyst that comprises silicon and at least one metal M that is selected from the group that consists of the elements of groups 4 and 5 of the periodic table and mixtures thereof, with the mass of metal M being between 0.1 and 20% of the mixed oxide mass.

A mesoporous mixed oxide catalyst that comprises silicon and at least one metal M that is selected from the group that consists of the elements of groups 4 and 5 of the periodic table and mixtures thereof, with the mass of metal M being between 0.1 and 20% of the mixed oxide mass.

An exhaust gas-purifying catalyst includes a support and a catalytic metal as one or more precious metals supported by the support. The support includes a composite oxide having a composition represented by a general formula AB.sub.C.sub.O.sub.3, wherein A represents one or more elements selected from the group consisting of lanthanum, neodymium, and yttrium, B represents iron or a combination of iron and aluminum, C represents one or more elements selected from the group consisting of iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, and each represents a numerical value within a range of more than 0 and less than 1, and and satisfy relational formulae of > and +1.