Increasing the CO₂/N₂ Selectivity with a Higher Surface Density of Pyridinic Lewis Basic Sites in Porous Carbon Derived from a Pyridyl‐Ligand‐Based Metal–Organic Framework

Abstract

The development of functional porous carbon with high CO2 /N2 selectivity is of great importance for CO2 capture. In this paper, a type of porous carbon with doped pyridinic sites (termed MOFC) was prepared from the carbonization of a pyridyl-ligand based MOF. Four MOFCs derived from different carbonizing temperatures were prepared. Structural studies revealed high contents of pyridinic-N groups and nearly the same pore-size distributions for these MOFCs. Gas-sorption studies revealed outstanding CO2 uptake at low pressures and room temperature. Owing to the high content of pyridinic-N groups, the CO2 /N2 selectivity on these MOFCs exhibits values of about 40-50, which are among the top values in carbon materials. Further correlation studies demonstrated that the CO2 /N2 selectivities show a positive linear relationship with the surface density of pyridinic-N groups, thus validating the synergistic effect of the doped pyridinic-N groups on CO2 adsorption selectivity.

Boosting ORR Catalytic Activity by Integrating Pyridine‐N Dopants, a High Degree of Graphitization, and Hierarchical Pores into a MOF‐Derived N‐Doped Carbon in a Tandem Synthesis

“…Furthermore, sensitive pyridine‐N sites may transform to the more stable form of graphitic‐N groups at high temperatures. This observation is in agreement with the findings for other N‐doped carbon materials . Several reactions, including N doping with NH 3 on a carbon matrix, N elimination by a decomposition reaction of N heteroatoms, the evolution of N dopants to other types of N dopants, and the activation reaction between NH 3 and carbon matrix, happen at the same time during the NH 3 etching process.…”

Metal–Organic‐Framework‐Derived Carbons: Applications as Solid‐Base Catalyst and Support for Pd Nanoparticles in Tandem Catalysis

“…It is noted that higher carbonization temperature leads to more weight loss (Table S1). To remove Al 2 O 3 , the Cz‐MOF‐253 was treated with 20 % HF and washed with deionized water . PXRD patterns of Cz‐MOF‐253 carbons exhibit broad and weak peaks around 24° and 44°, which can be indexed to the diffraction peaks of (002) and (101) of graphitic carbon .…”

“…To remove Al 2 O 3 ,t he Cz-MOF-253 was treated with 20 %H Fa nd washed with deionized water. [20] PXRD patterns of Cz-MOF-253 carbonse xhibit broad and weak peaks around248 and 448,which can be indexedtothe diffraction peaks of (002)a nd (101) of graphitic carbon. [21] X-ray photoelectron spectroscopy (XPS) analysis indicates the atomic percentage of Ni nC z-MOF-253-700, -800, -900, and -1000 are 9.4, 8.5, 7.0, and 3.7%,r espectively ( Table S2 in the Supporting Information).…”

Tuning the Surface Polarity of Microporous Organic Polymers for CO2 Capture

“…[22,23] CaCO 3 , NaHCO 3 ,M gCO 3 ,L i 2 ZrO 3 ,L i 4 SiO 4 ,K 2 CO 3 ,a nd Na 2 CO 3 in pure or supported form can chemically adsorb CO 2 with high selectivity,b ut their regeneration is costly in energy and the diffusion of CO 2 through the bulk matrix always causes deactivation with repeated use. [24,25] Recently,p orousm aterials, such as metal-organic frameworks (MOFs), [26][27][28][29][30][31] porousp olymers, [32][33][34][35] and mesoporous materials, [36][37][38] have been developed as new types of materials for CO 2 capture. Of these materials, microporous organic polymers (MOPs) are very interesting due to, for example, their robustness, facile synthesis, easy functionalization, rich porosity.…”