Goals:
Synthesis of catalysts for control of automotive exhaust emission. 

Introduction:
Presently air pollution is a major concern for industrial countries. More than 75% of the air pollution is related with the pollutants coming out from automobiles.

Catalytic converter is a device that is used for the synchronized transforming of exhaust pollutant emitted from machines. In this project we used monolith as a substrate, which has less pressure drop in comparison with pellet carrier because gas route is chanalized.

Gamma –Alumina as catalyst carrier and Pd as active phase were used, because it is cheaper and more abundant in comparison with other noble metals. Some promoters such as Ba, Ce, and La were added to carrier in order to approach catalyst performance to costum commercialized catalysts ( Pt-Pd-Rh).

Approach: This work was performed as a research proposal at RIPI.

Accomplishment:

- Increasing in solid percentage (in slurry ) causes increasing in wash coat thickness and surface area, and consequently the activity decrease and also the wash coat adherence to monolith are improved.

- Declining in pH lead to decreasing of wash coat thickness and wash coat adherence to monolith, also the performance of catalyst decreases. However the amount of pH hasn’t any effect on BET surface area.

- The more grinding time passes, the less thickness, BET surface area and the adherence of wash coat to monolith were obtained.

Advantages:

Because of the low price of Pd compared to Pt and Rh, the Pd-only catalysts developed in this work are more economical.