Catalyst Improvements to Meet European Stage III and ULEV Emissions Criteria

Gold, an alternative to platinum group metals in automobile catalytic converters

“…The gold-based catalyst, NS Gold™, is now in production with one of the four largest European diesel car manufacturers [74]. It is reported that this catalyst enables manufacturers of light-and heavy-duty diesel engines to reduce noxious emissions by as much as 40% more than with Pt catalysts at the same cost [75,76]. When compared to Pt-Pd catalysts, the use of NS Gold™ can potentially increase HCs oxidation activity by 15-20% at equal precious metal cost.…”

“…When compared to Pt-Pd catalysts, the use of NS Gold™ can potentially increase HCs oxidation activity by 15-20% at equal precious metal cost. With a tri-metal formulation of Au, Pt and Pd, NS Gold™ allows the proportions of each metal to be adjusted to meet engine-specific performance targets and stabilise the overall cost of diesel catalysts, despite fluctuations in the price of precious metals [75,76]. It is reported that NS Gold™ is potentially suitable for treating all lean-burn exhausts.…”

“…It is reported that NS Gold™ is potentially suitable for treating all lean-burn exhausts. Applications include, but are not limited to, treating particulates and hydrocarbons in soot filters, stationarysource volatile organic compound emissions and ammonia slip in SCR systems [75,76].…”

“…One strategy is based on quickly bringing the catalyst to working temperature, including close-coupled or manifold mounted catalysts [75], electrically heated catalysts [78], exhaust gas ignition (EGI) [79,80] and combustion heated catalysts [81]. A variety of heat storage devices have also been suggested, all of which work on the principle of retaining heat from the time of the last car's shutdown until the following cold start [82].…”