Circuit breaker comprising a ceria-based catalyst for CO conversion into CO2

A circuit breaker, comprising an enclosure comprising:

• at least two arcing contacts that are movable axially relative to each other, between an open position of the circuit breaker in which the arcing contacts are separated from each other and a closed position of the circuit breaker in which the arcing contacts are in contact with each other,
• an inlet to the enclosure, the inlet configured to blow an arc-control gas in order to interrupt an electric arc that is likely to form during movement of the arcing contacts from the closed position to the open position of the circuit breaker, the arc-control gas being oxygen-free, comprising at least 80% of carbon dioxide, wherein the arc-control gas is a gas mixture comprising CO2 and at least one fluorinated compound, wherein the arc-control gas comprises from 90 to 97% by volume of carbon dioxide and from 3 to 10% by volume of the at least one fluorinated compound,
• wherein the enclosure is at least below 100° C., further comprising a catalytic material, which converts carbon monoxide that forms after ionization of the carbon dioxide during arcing, into carbon dioxide, the catalytic material comprising ceria and a precious metal, and the catalytic material being supported by a substrate comprising a ceramic substrate.