CATALYST FOR PRODUCING UNSATURATED CARBOXYLIC ACID BY GAS PHASE OXIDATION OF UNSATURATED ALDEHYDE Russian patent published in 2019 - IPC B01J23/887 B01J23/00 B01J23/888 B01J23/94 B01J35/00 B01J35/10 B01J35/02 B01J35/04 B01J37/02 B01J37/04 B01J37/08 C07C51/25 C07C51/235 C07C51/50 C07C57/55 

FIELD: chemistry.

SUBSTANCE: described catalyst for producing α,β-unsaturated carboxylic acid by gas-phase oxidation of α,β-unsaturated aldehyde, wherein the catalyst includes a moulded body support having an active material applied thereto, characterised in that the degree of coverage of the active mass q, where , is at most 0.26 mg/mm², wherein Q is the proportion of the active mass of the catalyst in wt. %, a S_m is the specific geometric surface of the moulded support in mm²/mg, and the active mass includes a multielement oxide of general formula (II) Mo₁₂V_aW_bCu_cX⁴_eX⁵_fO_n (II) where X⁴ is one or more alkali and / or alkali-earth metals, X⁵ is one or more elements from the group of Si, Al, Ti and Zr, a is a number ranging from 2 to 4, b is a number ranging from 0 to 3, c is a number between 0.5 and 3, e is a number ranging from 0 to 2, f is a number ranging from 0 to 40 and n is the stoichiometric coefficient of the oxygen element, which is determined by the stoichiometric coefficients of elements other than oxygen, as well as their valence in (II). Also described is a method for producing a catalyst, as well as a method for producing α,β-unsaturated carboxylic acid by gas-phase oxidation of α,β-unsaturated aldehyde with molecular oxygen on a solid catalyst bed, which includes at least two consecutive reaction zones, and backfilling at least closest to the reactor inlet of the reaction zone includes a catalyst.

EFFECT: due to the catalyst with still high conversion of acrolein, the over-oxidation to CO_x is reduced and the selectivity of the formation of acrylic acid increases.

14 cl, 14 dwg, 5 tbl, 13 ex