Highly efficient catalysts for reducing toxic gases generation change with temperature of rigid polyurethane foam nanocomposites: A comparative investigation

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.