Measurements of the impact of carbon monoxide on the performance of passive autocatalytic recombiners at containment-typical conditions in the THAI facility

•Passive autocatalytic recombiner tests performed in technical scale containment facility.•Evaluation of influence of carbon monoxide on PAR performance.•PAR exposed to oxygen starvation impacts hydrogen but not carbon monoxide conversion.•PAR ignition limit is shifted to lower hydrogen concentration if carbon monoxide is present.•Catalytic recombination of carbon monoxide in absence of hydrogen under late phase temperature.