Super-activated CNB for CO2 capture: The development of the nitrogen containing porous carbon by chlorination and post KOH-activation

Highlights: • Nanoporous boron and nitrogen co-doped carbon (CNB) having high oxidation stability. • Simultaneous increase in micropore volume and nitrogen content of CNB by activation. • Activated CNB exhibiting outstanding CO₂ capturing capacity among carbon materials. • The need for improving CO₂ uptakes per unit micropore volume in carbonous adsorbent. -- Abstract: Minimization of carbon dioxide (CO₂) emissions into the atmosphere is a prerequisite to solving climate change. Tremendous research has been conducted to capture the CO₂ from pre- and post-combustion using nanoporous materials. Nitrogen-doped porous carbon is one of the most promising CO₂ adsorbents. Achieving high nitrogen content and high micropore volume is essential to CO₂ adsorption properties. In this study, super activated nitrogen and boron co-doped porous carbons (K-CNBs) are successfully synthesized by the chlorination and the subsequent KOH chemical activation. Nitrogen and boron co-doped porous carbons (CNBs) are synthesized by the chlorination of titanium carbonitride and boride mixture. CNBs good thermal and oxidation stability that induces an increase in the nitrogen content as well as an increase in the micropore volume even after the activation. K-CNBs, having both high micropore volume and abundant pyridonic-N functional group, show superior CO₂ uptake at ambient temperature at atmospheric pressure with excellent CO₂/N₂ selectivity. K-CNBs are the best CO₂ capturer among the nitrogen-containing carbon materials, reaching the threshold of CO₂ uptakes performance.