Preparation of highly sulfonated hyper-crosslinked polymers as promising ammonia adsorbents with excellent performance

The capture of ammonia (NH 3 ) from exhaust gases is essential for improving the environmental quality and ecological health. Developing structurally stable adsorbents with excellent performance remains a challenge. In this work, we synthesized three novel sulfonated hyper-crosslinked polymers (sHCPs) with distinct structural characteristics and evaluated their NH 3 adsorption performance. Notably, the preferred sHCP-1 demonstrated remarkable stability and an impressive NH 3 uptake capacity of 11.54 mmol/g at 30℃ and 1.0 bar. Moreover, it can maintain an NH 3 adsorption capacity exceeding 10.0 mmol/g after ten regeneration cycles. The adsorption of NH 3 on the sHCP-1 conformed to the pseudo second kinetic and Weber-Morris diffusion models. Comprehensive thermodynamic and spectroscopic analyses of NH 3 on sHCP-1 were performed to elucidate the adsorption behavior. The adsorption mechanism clarified that the well-developed micro/mesoporous structure provided abundant adsorption sites, where the chemisorption between acidic -SO 3 H groups and basic NH 3 facilitated the formation of NH 4 + from NH 3 . Present work systematically investigated the NH 3 adsorption process of sHCPs, offering valuable insights for the development of efficient and reversible NH 3 adsorbents.