Highly Efficient Nitrogen-Doped Porous Carbonaceous CO 2 Adsorbents Derived from Biomass

In this manuscript, N-doped porous carbonaceous CO 2 sorbents were synthesized using biomass waste hazelnut shell as the raw materials, melamine as the nitridation agent, and KOH as the porogen. The resultant materials were carefully characterized by different techniques, and the results show that these samples possess a high amount of N content and highly developed porous structure. As a result, high CO 2 adsorption capacities were found for this series of sorbents, up to 4.23 and 6.34 mmol/g at 1 bar and 25 and 0 °C, respectively. Comprehensive investigation indicates that, in addition to the well-known narrow microporosity and N content, the pore size distribution of the adsorbent also plays an important role in dictating the CO 2 uptake under ambient conditions. Thus, it is proposed that the joint effect of the above three factors dictates the CO 2 adsorption capacity of these sorbents. Moreover, these sorbents exhibit many other exceptional CO 2 adsorption properties, such as stable recyclability, fast adsorption kinetics, suitable heat of adsorption, high CO 2 /N 2 selectivity, and good dynamic CO 2 capture capacity. The wide availability and low cost of raw materials together with a straightforward synthesis procedure and excellent performance disclose the high potential of hazelnut-shell-derived carbons in CO 2 capture.