Huge　consumption　of　rigid　polyurethane　foam　(RPUF)　brings　about　two　serious　challenges　for　our　society:　fire　hazards　and　environmental　pollution.　To　address　these　issues,　metal　oxides　and　bimetallic　oxides　used　for　reducing　smoke　toxicity　was　successfully　synthesized.　The　structures　and　morphologies　were　confirmed　and　thermogravimetric　analysis　indicated　that　incorporation　of　2　wt%　NiO　conspicuously　increased　the　residual　yield　of　RPUF　nanocomposites　by　63.8%　due　to　its　catalytic　coupling　effect.　Additionally,　through　the　thorough　analysis　of　volatile　and　condensed　products,　the　smoke　toxicity　suppression　mechanism　in　the　pyrolysis　and　combustion　of　RPUF　was　investigated　so　as　to　find　out　the　conversion　of　CO　to　CO2　through　a　redox　cycle,　involving　the　reduction　of　Ni+-Ni0　by　CO　and　the　oxidation　of　Ni0-Ni+　by　O2.　Among　all　the　additives,　nickel　molybdate　is　the　best　catalyst　which　facilitates　the　migration　of　fuel-N　in　RPUF　into　the　pollution-free　gas　in　pyrolysis　and　combustion　process.　©　2018