Method for preparing catalyst for acrolein and acrylic acid

Abstract

The invention discloses a method for preparing a catalyst for acrolein and acrylic acid, which is characterized in that: the catalyst consists of an active component supporter and an inert alumina carrier; the main composition elements of the active component are selected from Mo, Bi, Co and / or Ni and Fe, and the active component also contains trace elements such as K, Na, Rb, Cs, Mg, Ca, Zn, B, P and W; the active component supported on the carrier accounts for 5 to 70 percent of the total weight of the catalyst; and the active component supporter is not prepared by coprecipitation, instead, initial raw materials of the elements of the above expression formula containing the active component are precipitated in aqua ammonia of ammonium molybdate step by step to prepare an active component precursor with core-shell distribution, and the active component precursor is dried and baked to prepare the active component.

Description

Technical field:

[0001] The invention relates to gas-phase catalytic oxidation of propylene by gas containing molecular oxygen, and provides a method for preparing a catalyst with high activity and long life for preparing acrolein and acrylic acid. Background of the invention:

[0002] Regarding the catalyst for the partial oxidation of propylene to acrolein, there have been many patent reports at home and abroad in recent years. As far as the catalyst composition is concerned, almost all of them are molybdenum-based multi-component catalysts. Many manufacturers have industrially produced such catalysts for the preparation of acrolein, or further oxidation for the preparation of acrylic acid. The main components in the catalyst include Fe 2 (MoO 4 ) 3 , α-Bi 2 (MoO 4 ) 3 、CoMoO 4 and NiMoO 4 , where α-Bi 2 (MoO 4 ) 3 It is a surface active center and acts as a selective oxidation; Fe 2 (MoO 4 ) 3 Promote redox; CoMoO 4 and NiMoO 4 play a structural stabilizi...