Complex oxide catalyst and process for preparation of acrylic acid

Abstract

A catalyst which is a complex oxide catalyst represented by the following general formula (1): Mo a V b W c Cu d A e B f C g D h E i O x   (1) (in which Mo is molybdenum; V is vanadium, W is tungsten, Cu is copper, A is at least an element selected from antimony, niobium and tin; B is at least an element selected from alkaline earth metals; C is at least an element selected from silicon, aluminum, titanium and zirconium; D is at least an element selected from phosphorus, tellurium, cerium, lead, arsenic and zinc; E is at least an element selected from Group IA and Group IIIb elements of the periodic table, boron, iron, bismuth, cobalt, nickel and manganese; and O is oxygen; a, b, c, d, e, f, g, h, i and x denote the atomic ratios of Mo, V, W, Cu, A, B, C, D, E and O, respectively; and where a=12, 2≦b≦15, 0≦c≦10, 0<d≦6, 0≦e≦6, 0<f≦10, 0<g≦10, 0≦h≦5, 0≦i≦5, and x is a numerical value determined by the extents of oxidation of the other elements) which is characterized by being formed of a complex oxide which is prepared by using, as at least a part of the supply sources of components B and C, a compound containing both of the components B and C is provided. The catalyst is useful for vapor phase catalytic oxidation, in particular, is suitable as a catalyst for preparing acrylic acid by vapor phase catalytic oxidation of acrolein.

1 . A catalyst which is a complex oxide catalyst represented by the following general formula (1):  
       Mo a V b W c Cu d A e B f C g D h E i O x   (1)  (in which Mo is molybdenum; V is vanadium, W is tungsten, Cu is copper, A is at least an element selected from antimony, niobium and tin; B is at least an element selected from alkaline earth metals; C is at least an element selected from silicon, aluminum, titanium and zirconium; D is at least an element selected from phosphorus, tellurium, cerium, lead, arsenic and zinc; E is at least an element selected from Group IA and Group IIIb elements of the periodic table, boron, iron, bismuth, cobalt, nickel and manganese; and O is oxygen; a, b, c, d, e, f, g, h, i and x denote the atomic ratios of Mo, V, W, Cu, A, B, C, D, E and O, respectively; and where a=12, 2b≦15, 0≦c≦10, 0<d≦6, 0≦e≦6, 0≦f≦10, 0≦g≦10, 0≦h≦5, 0i≦5, and x is a numerical value determined by the extents of oxidation of the other elements)    which is characterized by being formed of a complex oxide which is prepared by using, as at least a part of the supply sources of components B and C, a compound containing both of the components B and C.    
     
     
         2 . A complex oxide catalyst as described in  claim 1 , in which the component B is at least an element selected from magnesium, calcium, strontium and barium.  
     
     
         3 . A complex oxide catalyst as described in  claim 1  or  2 , in which the component C is at least an element selected from silicon and aluminum.  
     
     
         4 . A complex oxide catalyst as described in any one of claims  1 - 3 , in which the compound containing both of the components B and C is heat-treated at 500-2000° C.  
     
     
         5 . A process for preparing acrylic acid through oxidation of acrolein at vapor phase with molecular oxygen or a molecular oxygen-containing gas in the presence of a catalyst, which is characterized in that the complex oxide catalyst of  claim 1  is used as the catalyst.