CATALYSTS FOR CONVERSION OF HYDROXYPROPIONIC ACID OR DERIVATIVES THEREOF INTO ACRYLIC ACID OR DERIVATIVES THEREOF Russian patent published in 2016 - IPC B01J27/18 B01J27/25 B01J35/10 B01J37/03 C07C51/377 C07C57/65 C07C57/55 

FIELD: chemistry.

SUBSTANCE: catalysts are mixed condensed phosphates, containing (a) at least one anion condensed phosphate of formula (I) [P_nO_3n+1]^(n+2)- (I), where n is equal to at least 2, and (b) at least two different cation. Catalyst, in fact, neutral charge, and molar ratio of phosphorus and said at least two different cations is from 0.7 to 1.7. Cations include: (i) at least one univalent cation; and (ii) at least one polyvalent cation, and the multivalent cation is selected from the group consisting of Be²⁺, Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Sn²⁺, Pb²⁺, Ti³⁺, Cr³⁺, Mn³⁺, Al³⁺, Ga³⁺, Y³⁺, In³⁺, Sb³⁺, Bi³⁺, Si⁴⁺, Ti⁴⁺, V⁴⁺, Ge⁴⁺, Mo⁴⁺, Pt⁴⁺, V⁵⁺, Nb⁵⁺, Sb⁵⁺ and mixtures thereof. Invention also discloses methods of producing catalysts. First method comprises steps of mixed and heated at least two different compounds containing phosphor, each said compound is described by one of the formulae (IV) and (XV), or any of hydrated forms said formulae M^I _y(H_3-yPO₄) (IV); M^II _vH_(4-2v)P₂O₇ (XV), where M^I represents a univalent cation; where M^II is a divalent cation; where y denotes 0, 1, 2 or 3; where v is 0, 1 or 2. Second method comprises steps of mixed and heated (a) at least one compound containing phosphorus, at that each said compound is described by one of the formulae (IV)-(VI) and (XV), or any of hydrated forms said formulae M^I _y(H_3-yPO₄) (IV); M^II _y(H_3-yPO₄)₂ (V); M^III _y(H_3-yPO₄)₃ (VI); M^II _vH_(4-2v)P₂O₇ (XV), where M^I represents a univalent cation; where M^II is a divalent cation; where M^III is a trivalent cation; where y denotes 0, 1, 2 or 3; where v is 0, 1 or 2; and (b) at least one compound does not contain phosphorus, selected from a group consisting of nitrate salts, at that each said compound is described by one of formulas (XXVI)-(XXVII), or any of hydrated forms said formulae M^INO₃ (XXVI); M^II(NO₃)₂ (XXVII). Third method comprises steps of (a) Ca₂P₂O₇ and KH₂PO₄ in molar ratio 3:1 to form a solid mixture, and (b) calcined said solid mixture of stepwise at 50 °C, 80 °C, 120 °C and at from 450 °C to 550 °C, to obtain said catalyst.

EFFECT: there are presented catalysts for dehydration of hydroxipropionic acid derivatives hydroxipropionic acid or mixtures thereof into acrylic acid, acrylic acid derivatives or their mixture with high output and selectivity, short-term stay and without significant conversion in undesirable by-products, such as, for example, acetaldehyde, propionic acid and acetic acid.

24 cl, 2 tbl, 13 ex