A selective catalytic pyrolysis strategy for fire safety biomaterials

Developing environmentally friendly and sustainable wood building materials must address the key issue of flame retardancy. However, conventional flame-retardant strategies bring potential environmental impacts and toxicity of combustion by-products. One option to solve this problem is to develop innovative flame-retardant strategies. Here, we present a new fire safety strategy that introduces potassium formate (HCOOK) to enable wood to selectively catalyze the active release of CO 2 . The CO 2 released during HCOOK pyrolysis enables to suppress the combustion reaction by diluting the combustible gases (ketones, aldehydes, phenols, etc.). Specifically, the incorporation of HCOOK is beneficial to the decarboxylation reaction (C=O) of cellulose at low temperatures of 170–310 °C, which promotes the production of CO 2 and improves the fire safety of wood. Additionally, the char layer hinders heat transfer and oxygen diffusion, providing effective fire protection. These synergistic effects of condensed phase and gas phase result in wood with excellent fire-retardant properties (limiting oxygen index of 35.8 %) and smoke suppression (total smoke production reduction 66.19 %). Furthermore, owing to the hydrogen bond interaction between HCOOK and wood, the wood exhibits exceptional mechanical properties (modulus of rupture, MOR, and modulus of elasticity, MOE). This study proposes a simple and environmentally friendly fire safety strategy for wood, providing valuable insights and laying a crucial foundation for the development of sustainable building materials in the future.