Copper-Chromium-Nickel Alloys for NOx Reduction Automotive Emission Control Catalysts

The development of two base metal NO_x reduction catalysts, IN-1013 and IN-1050 is described. The catalysts are based on unique alloys of copper, chromium and nickel which form protective and catalytically active surface scales. The alloys are prepared as prealloyed powders and can be formed into a variety of low mass, high surface, open structures by deposition on suitable metal preforms.

Laboratory and engine dynamometer tests indicate catalytic capability for high net NO_x conversions at 1100°F and above. “Three-way” operation may also be possible. The air/fuel ratio “window” for either mode of operation is shown to be significantly greater for fluctuating exhaust compositions than for steady state conditions. Limited durability tests indicate capability to perform as a NO_x reduction catalyst for extended mileage, but HC conversion fades with catalyst aging. One example of a current vehicle emission control system using IN-1013 is described.