Modified carrier, complex oxide catalyst and process for preparation of acrylic acid

A complex oxide catalyst in which a complex oxide containing molybdenum and vanadium is supported on a carrier, characterized in that said complex oxide containing molybdenum and vanadium is a complex oxide which is expressed by the following general fomula (2):

• MOeVfWgCuhAiBjOk (2)
• (where MO is molybdenum, V is vanadium, W is tungsten, Cu is copper, A is selected from the group consisting of antimony, niobium and tin;
• B is selected from the group consisting of phosphorus, tellurium, lead, arsenic and zinc, and O is oxygen;
• e, f, g, h, i, j and k denote atomic rations of Mo, V, W, Cu, A, B and O, where a=12, 2≦f≦15, 0≦g≦10, 0≦h≦6, 0i≦6, 0≦j≦5, and k is a numerical value determined by the valences and number of occurrences of the other elements), and
• said carrier is a modified carrier having on a surface of an inert carrier an oxide expressed by the formula (1):
• XaYbZcOd (1)
• (wherein X is selected from the group consisting of alkaline earth metals;
• Y is selected from the group consisting of silicon, aluminum, titanium and zirconium;
• Z is selected from the group consisting of Group IA elements and Group IIB elements of the periodic table, boron, iron, bismuth, cobalt, nickel and manganese;
• of X, Y, Z and O, respectively, and where a=1, 0<b<100 and 0<c<10 and d is a numerical value determined by the valances and number of occurrences of the other elements).