A wood stove catalyst isn't a filter. Instead of physically capturing particles, the combustor deploys chemical catalysis to break apart unburned particles. Platinum and/or palladium atoms loaded in honeycomb cells trigger the chemical reaction. Your catalyst converts smoke into water vapor, carbon dioxide, and HEAT.
Catalysis is used in other catalytic converters, such as automobiles, but wood stoves are virtually unique in benefiting from the HEAT that the catalytic reaction produces.
Emissions from chimney become invisible carbon dioxide and white water vapor. Chimney emissions from inferior or worn-out catalysts are dark.
What does light-off temperature mean?
Chemical catalysis doesn't take place at any temperature lower than light-off temperature. That's why your stove bypass diverts around the catalyst during warm-up.
For ceramic honeycomb catalysts light-off occurs when your woodstove reaches about 500° Fahrenheit (260° Celsius),
For Condar steel honeycomb catalysts, light-off temperature is reached faster, at approximately 400° Fahrenheit (204° Celsius).
Use a woodstove thermometer or Watchman electronic catalyst monitor to monitor temperature of the catalyst and achieve maximum catalytic reaction during your burn.
Catalytic reaction maxes out at about 1300° Fahrenheit through any combustor. Exceeding this temperature is destructive to the combustor and to the components of your stove.