1998-02-23

Influence of Support Materials on Durability of Palladium in Three-Way Catalyst 980664

In this paper, we studied the influence of support materials on Pd in three-way catalysts for the aim of enhancing the durability of Pd, particularly CO and NOx conversion efficiencies which are usually seriously damaged after aging. Since the durability of precious metals was found to be strongly influenced by the support material chosen, it should be possible to optimize catalyst performance by finding the appropriate support.
The performance of Pd three-way catalysts with different support materials (Aluminum oxide, Cerium - Zirconium Oxide, Cerium - Zirconium -Yttrium Oxide, Zirconium Oxide, or Titanium Oxide) was compared after high temperature agings under various gas conditions.
To assess Pd deterioration, the crystallite size of Pd was measured with XRD and the micro surface was observed by FE-SEM. The performance of the catalysts was evaluated.
In summary, Pd supported on Aluminum oxide maintained the smallest crystallite size, by maximizing activation points which is imperative under the static A/F condition.
On the other hand, Pd supported on Cerium -Zirconium - Yttrium Oxide (Ce-Zr-Y oxide) showed the best performance under A/F fluctuating conditions to simulate a close coupled catalyst. It is considered that Pd supported directly on Ce-Zr-Y oxide promoted the rapid response of Oxygen Storage Capacity (OSC).

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Solid State Electrochemical Cell for NOx Reduction

929418

View Details

TECHNICAL PAPER

Numerical Simulation of Deactivation Process of Three-way Catalytic Converters

2000-01-0214

View Details

TECHNICAL PAPER

Development of the Automotive Exhaust Hydrocarbon Adsorbent

2001-01-0660

View Details

X