Honeycomb heater

Abstract

A honeycomb heater includes a honeycomb structure having a periphery, a front end, and a back end, including a plurality of passages which are defined by partition walls and extend in an axial direction of the honeycomb structure, the honeycomb structure being electrically conductive, whereby fluid flows through the passages from the front end to the back end; and a device for applying electric current to the honeycomb structure so as to generate heat; wherein at least one gap for obstructing electric current extends through the partition walls from the back end toward the front end but does not reach the front end so that, upon applying electric current to the honeycomb structure, a front region of the honeycomb structure heats more quickly than a back region of the honeycomb structure thereby a catalyst composition loaded onto the front region is activated earlier. Slit may extend between the front end and the back end. The back end may be depressed so that a front region which is located between the depression and the front end heats more quickly than a back region of the honeycomb structure. A catalytic converter includes: (A) the honeycomb heater; and (B) a catalyst element, which is arranged downstream of the honeycomb heater, including: a monolithic structure including a plurality of passages which are defined by partition walls; and a catalyst composition loaded on at least a part of the partition walls of the monolithic structure, the catalyst composition including: an inorganic oxide resistant to heat; and a catalytically active component, loaded on the inorganic oxide, including an element selected from the group consisting of platinum, palladium, rhodium, and iridium.