Darrell Morris

Advanced Three-Way Catalysts - Optimisation by Targeted Zoning of Precious Metal

Emissions from (and cost of) three-way catalysts can minimised by targeted application of PGM along the catalysts length rather than the conventional homogeneous distribution. Experiments are described demonstrating pollutant conversion as a function of catalyst length during the European MVEG-B cycle. It is shown that most pollutant conversion occurs on the front portion, and that therefore the most effective catalysts have the majority of the PGM content there. Further analysis of the three legislated pollutants CO, HC and NOx leads to insights about the optimum distribution of Pt, Pd and Rh within the catalyst. In advantageous circumstances bi or trimetallic systems can be partially replaced with Rh-only systems with significant cost and backpressure benefits. Further experiments comparing zoned catalysts with current catalysts whose PGM is homogeneously distributed are described, demonstrating additional performance benefits.

The Effect of Phosphorus and Boron Lubricant Oil Additives on Catalyst and Engine Durability

To investigate the effect of removing phosphorus lubricant additives from engine oil, a mileage accumulation programme was run using four 1.6 litre gasoline vehicles, two of which used phosphorus based lubricant oil additives, and the other two used boron based lubricant oil additives. The work showed that the catalyst systems deactivate during mileage accumulation, but emissions were still within the European Stage IV legislative limits at the completion of the mileage accumulation program e. Vehicles run with the boron oil show lower tailpipe emissions than the vehicles run with the phosphorus oil.