Oxide catalyst is mainly the vanadium based catalyst, and adding co-agents like tungsten trioxide, such kind of catalyst has a high NOx removal efficiency in the temperature range of 300-400°C with excellent stability. In the past, the catalyst of diesel engined car exhaust is primarily the noble metal catalyst, but its application is limited by high cost. An invention has pointed out that a method for preparing the diesel engined car exhaust tungsten trioxide denitration catalyst which has a high catalytic activity, wide temperature window, as follows:

 

1. Calcine carrier of the titanium dioxide at 300-400°C for 2-5 hours;

2. Preparation of the active ingredient solution: dissolve the ammonium metavanadate and ammonium metatungstate in deionized water, then add the appropriate amount of oxalic acid solution and uniformly stirred, to obtain the active catalyst component solution;

3. Impregnation method to load the active component: The carrier is immersed in the calcined active component solution prepared in step 2;

4. Natural drying the catalyst obtained in step 3, then transferred to drying conditions at 80~120°C for 8~12 hours;

5. After drying, the catalyst is calcined at 300~600°C for 2 to 5 hours, then heated to 680-800°C and continually calcined for 2 to 5 hours to obtain the tungsten trioxide denitration catalyst which is suitable for diesel engined car exhaust.

Noted: wherein the carrier is titanium dioxide which takes 90-99.5% of the mass of catalyst; the main active component vanadium pentoxide takes 0.5-10%; additive- tungsten trioxide takes 0.5-10%.

 

The preparation method of this catalyst without introducing any chemical agent, just by changing the preparation process; by changing the calcining temperature to improve the distribution of the active component in the catalyst support surface, has the advantages of simple operation, excellent repeatability, easy to optimize the size and modifying the conventional catalyst.