METHOD OF PRODUCING CATALYST FOR SYNTHESIS OF UNSATURATED CARBOXYLIC ACID Russian patent published in 2023 - IPC B01J37/04 B01J37/08 B01J23/887 C07C51/235 C07C57/55 

FIELD: pharmaceuticals.

SUBSTANCE: invention relates to a method of producing a catalyst for the synthesis of unsaturated carboxylic acids, namely, the production of carboxylic acids by gas-phase catalytic oxidation of an unsaturated aldehyde. The method of producing a catalyst includes several stages. At the first stage, the mixture of solutions of starting materials is dried. The catalyst precursor is then formed by applying the dry product obtained previously to the carrier. The final catalyst is then obtained by calcining the catalyst precursor. The process is characterized by varying degrees of mass loss: powder for application at 300°C is less than 5 mass percent, and the difference between the second degree of mass loss of the powder for application at 370°C and the first degree of mass loss of powder for application at 300°C ranges from not less than 1 weight percent to not more than 6 weight percent. The first and second degrees of mass loss of the application powder are calculated based on the following formula based on the masses of the application powder before and after heating the application powder to 300°C and 370°C in the air atmosphere until no change in mass is achieved. The degree of weight loss is calculated using the following formula: degree of weight loss (% (wt.)) = [(mass of powder for application before heating (g) – mass of powder for application after heating (g))/weight of powder for application before heating (G)]× 100. The catalyst obtained by the described method is described by the following compositional formula: Mo₁₂V_aX_bCu_cY_dSb_eZ_fSi_gC_hO_i where X is Nb and/or W, Y is at least one element selected from the group consisting of Mg, Ca, Sr, Ba and Zn, and Z denotes at least one element selected from the group consisting of Fe, Co, Ni and Bi; and the indices from a to i denote the atomic fractions of the corresponding elements, where the indices from a to h satisfy the following relations: 0< a≤12, 0≤ b≤12, 0 < c≤12, 0≤ d≤8, 0≤ e ≤ 500.0≤ f≤500, 0≤ g≤500 and 0≤ h≤500, and i represents the value corresponding to the oxidation states of other elements.

EFFECT: method of producing the catalyst proposed in the invention makes it possible to increase the degree of conversion of the raw material and selectivity for the final product, which improves the yield during the synthesis process.

5 cl, 1 tbl, 7 ex