Hollow-Tube Catalyst Substrate Promises 3% Fuel Savings

British researchers have developed a ceramic hollow-fiber substrate for catalytic converters they say is 50% smaller, uses 80% less precious metal and boosts fuel economy 2%-3% compared with conventional architectures, Green Car Congress reports.

The group at Imperial College London has founded a company, MicroTech Ceramics Ltd. in Kent, to commercialize its technology.

The substrate consists of a bundle of tiny ceramic tubes the researchers say increases the geometric surface area available for a catalytic coating by 60%-300%. Adding surface area reduces the amount of catalyst by reducing diffusion limitations of the washcoat used to apply it to the substrate. More surface area also improves the converter's reactivity.

The tubes also are connected radially by micro-channels that improve gas flow. The researcher say their design reduces exhaust backpressure, thus contributing to engine fuel efficiency. They also claim that lab tests indicate their structure deteriorates only 4% over 100,000 km compared with 35% typical of a conventional honeycomb catalytic converter.