Internal combustion engines produce toxic combustion by-products. Every country has regulations that limit their permissible amounts. Catalytic converters are devices in which a chemical reaction transforms these toxic combustion by-products into non-toxic substances. The entire structure is fitted into a metal housing (Figure 1) and generally positioned between the engine and the muffler in modern vehicles. Converters consist of three components: The core or substrate, usually composed of a ceramic honeycomb structure that increases the amount of surface area available to support the catalyst (Figure 2). The washcoat (usually a mixture of silica and alumina) which when added to the core creates an irregular rough surface which further increases the surface area for active precious metal sites. The catalyst itself, commonly containing a mixture of platinum-group metals such as platinum and palladium. Diesel engines in particular use large amounts of platinum due to the operating conditions of these engines.

Figure 1: Diesel catalytic converter on a Dodge Ram. Figure 2: Honeycomb core

Nanostellar's first application area is catalysts for diesel emissions control. Catalytic converters in light-duty diesel vehicles (passenger cars) and heavy-duty diesel vehicles (trucks) use precious metals to catalyze the oxidation of harmful byproducts in the engine exhaust. These precious metals, in particular platinum, have seen their prices rise over the past 15 years as diesel engines have become more prevalent and as emissions standards have become more strict. In mid-2010, the precious metal content of a diesel catalytic converter ranged from $200 to $700, depending on the size of engine and the relative proportions of platinum and palladium used.

Precious Metal Content by Engine Size

Nanostellar has designed catalysts that increase performance while reducing the cost of required precious metals. These catalysts use gold and non-precious metals along with traditional platinum and palladium. Nanostellar has scaled up the production of its materials to commercial quantities in conjunction with its strategic partners. The materials and their associated manufacturing and coating methods are the subjects of several Nanostellar patents.



Nanostellar's materials are designed to be used in conjunction with existing coating techniques, making them compatible with established manufacturing protocols in the industry.