A process and apparatus for accelerating the rate of heating of a fixed bed catalyst to a light-off temperature for a catalytic reaction is disclosed. Supplementary energy from an external energy source is provided to a predetermined area of the catalyst bed for a limited period of time. The fixed bed catalyst may be present as a solid body or in bulk form and has a gas inlet area defined by a cross-section of the flow through channels of the reaction media. The supplementary energy is supplied to one or more isolated sections of the gas inlet area of the catalyst. Such a system significantly reduces the energy required in order to effectuate at least partial conversion of harmful emissions during initial operation of the converter.