Cross-linked polymer-derived B/N co-doped carbon materials with selective capture of CO2

Abstract

A new series of B, N-containing cross-linked polymers (PPs-BN) were achieved via Sonogashira cross coupling. These polymers exhibit very high carbon yields of around 70–80% even at 800 °C, which allow them to be efficiently converted to B/N co-doped porous carbons after pyrolysis at high temperature under an inert atmosphere. The materials have been fully characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analyses, nitrogen sorption measurements and X-ray photoelectron spectroscopy, revealing their high contents of boron and nitrogen up to ∼3.21% and ∼5.72%, respectively, as well as porous structures with the largest specific surface area of 291 m² g⁻¹. Their CO₂ capacities reached 3.25 mmol g⁻¹ at 273 K under 1 atm. In addition, the very high selectivity for CO₂/CH₄ with a ratio of more than 5 : 1 at 298 K renders them applicable for gas separation and purification.