Nitrogen-doped Microporous Carbon Research Articles

Synergistic effect of pore generation and nitrogen doping on the enhanced CO2 capture and selectivity of carbon nanofibers

The porosity and heteroatom doping of carbon materials are crucial for their adsorption capacity and selectivity toward CO2. Herein, nitrogen-doped microporous carbon nanofibers (CNFs) were prepared by carbonizing electrospun polyacrylonitrile (PAN) nanofibers, using nitrogen-rich polyvinylpyrrolidone (PVP) as porogen and nitrogen source simultaneously. The synergistic effect of pore generation and nitrogen doping improved the porosity and preserved a substantial nitrogen content in the CNFs. Compared to the nitrogen-free polyethylene glycol (PEG) porogen, the incorporation of PVP can facilitate nitrogen doping during the carbonization process. With an increasing amount of PVP addition, the specific surface area of the CNFs significantly expanded to 410 m2/g, maintaining a high nitrogen content of 10.32 wt%. The porosity and nitrogen functionalities (Pyridinic N and pyrrolic N) collaborated synergistically in determining CO2 adsorption capacity, with elevated nitrogen content resulted in improved selectivity. The CNFs exhibited remarkable IAST CO2/N2 (10:90) selectivity of 38 and cycling stability, demonstrating their potential for long-term practical applications. This work provides unique inspiration for the design of porous nanofibers with exceptional CO2 adsorption capacity and selectivity.

A facile synthesis of iron single-atom electrocatalyst for high-performing oxygen reduction reaction and remarkable rechargeable zinc-air battery

Iron-based single-atom catalysts (SACs) are considered to the most promising catalysts to replace Pt for efficient oxygen reduction reaction (ORR). However, the precise synthesis of high-performance SACs and the understanding of their ORR origin remain challenging. In this work, microporous nitrogen-doped carbon with abundant and accessible atomically dispersed N-coordinated Fe sites (Fe-N-C) is prepared by molecular-confined coupling pyrolysis strategy. The Fe-N-C exhibits excellent ORR activities in acid (E1/2 of 0.78 V vs. RHE) and alkaline (E1/2 of 0.91 V vs. RHE) electrolytes. When integrated into a rechargeable aqueous Zinc-air battery (ZAB), both large specific capacity (770 mAh g−1) and high peak power density (240 mW cm−2) are achieved. Remarkably, the as-prepared ZAB presents amazing charge-discharge cycle performance of 1600 h at the large current density, which is 52.5 times of that using Pt/C+RuO2. Furthermore, all-solid-state ZAB delivers ultra-robust cycling stability even under bending. This work may advance a critical step towards the design of rational and controlled preparation of remarkable and ultra-stable catalysts.

Encapsulating Sulfur into a Gel-Derived Nitrogen-Doped Mesoporous and Microporous Carbon Sponge for High-Performance Lithium-Sulfur Batteries.

The practical application of Li-S batteries (LSBs) has long been impeded by the inefficient utilization of sulfur and slow kinetics. Utilizing conductive carbonaceous frameworks as a host scaffold presents an efficient and cost-effective approach to enhance sulfur utilization for redox reactions in LSBs. However, the interaction of pure carbon materials with lithium polysulfide intermediates (LiPSs) is limited to weak van der Waals forces. Hence, the development of an economical method for synthesizing heteroatom-doped carbon materials for sulfur fixation is of paramount importance. In this study, we introduce a hierarchical porous nitrogen-doped carbon sponge (NPCS) with an exceptionally high BET surface area of 3182.2 m2 g-1, achieved through a facile template-assisted polymerization method. The incorporation of inorganic salts, free radical polymerization, and deuteric freeze-drying techniques facilitates the formation of hierarchical pores within the NPCS. After sulfur fixation, the resulting S/NPCS electrode demonstrates remarkable electrochemical performance in LSBs. Specifically, it achieves an 80% sulfur utilization rate, maintains a high reversible specific capacity of 400 mA h g-1 even after 600 cycles at a demanding current density of 5.0 A g-1, and exhibits superior rate capability. It is believed that this work will inspire the rational design of cost-effective carbon-based electrodes for high-performance LSBs.

Kraft Lignin-Derived Microporous Nitrogen-Doped Carbon Adsorbent for Air and Water Purification.

The study presents a streamlined one-step process for producing highly porous, metal-free, N-doped activated carbon (N-AC) for CO2 capture and herbicide removal from simulated industrially polluted and real environmental systems. N-AC was prepared from kraft lignin─a carbon-rich and abundant byproduct of the pulp industry, using nitric acid as the activator and urea as the N-dopant. The reported carbonization process under a nitrogen atmosphere renders a product with a high yield of 30% even at high temperatures up to 800 °C. N-AC exhibited a substantial high N content (4-5%), the presence of aliphatic and phenolic OH groups, and a notable absence of carboxylic groups, as confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Boehm's titration. Porosity analysis indicated that micropores constituted the majority of the pore structure, with 86% of pores having diameters less than 0.6 nm. According to BET adsorption analysis, the developed porous structure of N-AC boasted a substantial specific surface area of 1000 m2 g-1. N-AC proved to be a promising adsorbent for air and water purification. Specifically, N-AC exhibited a strong affinity for CO2, with an adsorption capacity of 1.4 mmol g-1 at 0.15 bar and 20 °C, and it demonstrated the highest selectivity over N2 from the simulated flue gas system (27.3 mmol g-1 for 15:85 v/v CO2/N2 at 20 °C) among all previously reported nitrogen-doped AC materials from kraft lignin. Moreover, N-AC displayed excellent reusability and efficient CO2 release, maintaining an adsorption capacity of 3.1 mmol g-1 (at 1 bar and 25 °C) over 10 consecutive adsorption-desorption cycles, confirming N-AC as a useful material for CO2 storage and utilization. The unique cationic nature of N-AC enhanced the adsorption of herbicides in neutral and weakly basic environments, which is relevant for real waters. It exhibited an impressive adsorption capacity for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) at 96 ± 6 mg g-1 under pH 6 and 25 °C according to the Langmuir-Freundlich model. Notably, N-AC preserves its high adsorption capacity toward 2,4-D from simulated groundwater and runoff from tomato greenhouse, while performance in real samples from Fyris river in Uppsala, Sweden, causes a decrease of only 4-5%. Owing to the one-step process, high yield, annual abundance of kraft lignin, and use of environmentally friendly activating agents, N-AC has substantial potential for large-scale industrial applications.

N-rich chitosan-derived porous carbon materials for efficient CO2 adsorption and gas separation.

Capturing and separating carbon dioxide, particularly using porous carbon adsorption separation technology, has received considerable research attention due to its advantages such as low cost and ease of regeneration. In this study, we successfully developed a one-step carbonization activation method using freeze-thaw pre-mix treatment to prepare high-nitrogen-content microporous nitrogen-doped carbon materials. These materials hold promise for capturing and separating CO2 from complex gas mixtures, such as biogas. The nitrogen content of the prepared carbon adsorbents reaches as high as 13.08wt%, and they exhibit excellent CO2 adsorption performance under standard conditions (1 bar, 273K/298K), achieving 6.97mmol/g and 3.77mmol/g, respectively. Furthermore, according to Ideal Adsorption Solution Theory (IAST) analysis, these materials demonstrate material selectivity for CO2/CH4 (10 v:90 v) and CO2/CH4 (50 v:50 v) of 33.3 and 21.8, respectively, at 1 bar and 298K. This study provides a promising CO2 adsorption and separation adsorbent that can be used in the efficient purification process for carbon dioxide, potentially reducing greenhouse gas emissions in industrial and energy production, thus offering robust support for addressing climate change and achieving more environmentally friendly energy production and carbon capture goals.

Nitrogen-doped coal-based microporous carbon material co-activated by HCOOK and urea for high performance supercapacitors

The doping of heteroatoms can adjust the surface chemical state of porous carbons, which is conducive to improving the surface activity, and enhancing the hydrophicity and conductivity of carbon electrodes. Herein, we developed a facile and green strategy to obtain nitrogen-doped coal-derived porous carbon dominated by micropores for high performance supercapacitor. The hydrothermal treatment of coal and urea can not only achieve the doping of nitrogen atoms, but also conducive to the subsequent activation process. Benefiting from the large micropore volume and specific surface area (0.68 cm3 g−1 and 1563 m2 g−1), suitable micropore size, and high content of surface CO, N-Q and N-5, the optimal sample exhibits a large capacitance of 371 F g−1 (1 A g−1), high capacitance retention of 67% (50 A g−1), and outstanding cyclic durability in a three-electrode system (aqueous electrolyte). Furthermore, the symmetrical supercapacitor in neat EMIM BF4 shows a high energy density of 40 Wh kg−1 (625 W kg−1). This work proposes a facile and potential strategy for preparing nitrogen-doped porous carbon materials with outstanding electrochemical property for supercapacitors and provides a novel insight for the efficient and low carbonization utilization of coal resources.

Robust nitrogen-doped microporous hollow carbon spheres for energy-efficient CO2 capture from flue gas

Nitrogen (N)-doped microporous hollow carbon spheres were prepared by facilely nanocasting spherical SiO2 with N-containing melamine phenolic resin through a simple in-situ polymerization process. Through regulating the dosage of melamine, N content in microporous hollow carbons could be easily tuned to an unprecedented level of 49.2 wt%. Additionally, in order to address the common problem of relatively poor structural porosity of N-doped carbons, especially after incorporating vast N into carbon frameworks in reported literature, a comprehensive strategy including optimizing carbonization temperature and performing further activation by CO2 and KOH were explored, and their effects on material textural properties and CO2 capacity were systematically studied. Although this strategy did not completely avoid the N loss during activation of carbon materials, it sharply promoted the textural properties of carbon materials at the expenses of partial N and efficiently produced a series of highly microporous carbon materials, still with abundant N species (11.5 ∼ 29.9 wt%) and large structural porosity (330 ∼ 1263 m2/g). More importantly, these N-doped microporous hollow carbons, when used for CO2 capture, showed superior CO2 capacities of 3.00 mmol/g (25 °C and 1 bar) and 1.05 mmol/g (40 °C and 0.1 bar), exceptionally robust cyclic stability, and low regeneration energy of 2.75 GJ/ton CO2, which is much lower than aqueous amine-based absorbents and comparable to amine-supported adsorbents. Thus, these outstanding adsorption performances make the N-doped microporous hollow carbon spheres prepared in this study more promising for energy-effective CO2 capture from dilute gas streams.

In-situ formation of nitrogen doped microporous carbon nanospheres derived from polystyrene as lubricant additives for anti-wear and friction reduction

This study presents a nitrogen-doped microporous carbon nanospheres (N@MCNs) prepared by a facile polymerization–carbonization process using low-cost styrene. The N element in situ introduces polystyrene (PS) nanospheres via emulsion polymerization of styrene with cyanuric chloride as crosslinking agent, and then carbonization obtains N@MCNs. The as-prepared carbon nanospheres possess the complete spherical structure and adjustable nitrogen amount by controlling the relative proportion of tetrachloromethane and cyanuric chloride. The friction performance of N@MCNs as lubricating oil additives was surveyed utilizing the friction experiment of ball-disc structure. The results showed that N@MCNs exhibit superb reduction performance of friction and wear. When the addition of N@MCNs was 0.06 wt%, the friction coefficient of PAO-10 decreased from 0.188 to 0.105, and the wear volume reduced by 94.4%. The width and depth of wear marks of N@MCNs decreased by 49.2% and 94.5%, respectively. The carrying capacity of load was rocketed from 100 to 400 N concurrently. Through the analysis of the lubrication mechanism, the result manifested that the prepared N@MCNs enter clearance of the friction pair, transform the sliding friction into the mixed friction of sliding and rolling, and repair the contact surface through the repair effect. Furthermore, the tribochemical reaction between nanoparticles and friction pairs forms a protective film containing nitride and metal oxides, which can avert direct contact with the matrix and improve the tribological properties. This experiment showed that nitrogen-doped polystyrene-based carbon nanospheres prepared by in-situ doping are the promising materials for wear resistance and reducing friction. This preparing method can be ulteriorly expanded to multi-element co-permeable materials. Nitrogen and boron co-doped carbon nanospheres (B,N@MCNs) were prepared by mixed carbonization of N-enriched PS and boric acid, and exhibited high load carrying capacity and good tribological properties.

Nitrogen-doped microporous carbons as highly efficient adsorbents for CO2 and Hg(II) capture

Nitrogen-doped microporous carbon, which features a uniquely tunable porosity, exhibits promisingly high adsorption prospects in the greenhouse gas capture and water treatment. Herein, we propose a series of novel N-doped microporous carbons (CMPAn-C1000), and precisely tune their porosities via a direct pyrolysis of rigid conjugated microporous poly(aniline)s (CMPAn, n = 1, 2, 3) with pore size difference in a molecular level, as achieved by simply tuning their linkers with varying sizes, planarity, and symmetry. The CMPA3-C1000, with a satisfactory amount of nitrogen heteroatoms, high SBET of ∼800 m2 g−1, and large ultra-micropore volume of 0.25 cm3 g−1, has excellent CO2 capture ability (i.e., 5.1 mmol g−1 at 273 K, 1 atm) and Hg(II) adsorption performance (i.e., Qe = 571 mg g−1; k2 = 0.0031 g mg−1 min−1), respectively. CMPA3-C1000 might perform chemisorption towards Hg(II), according to calculations using density functional theory and experimental data; nitrogen atoms in porous carbon contributed to this excellent Hg(II) adsorption.

Facile preparation of nitrogen-doped microporous carbon from potassium citrate/urea for effective CH4 separation and uptake

N-doped microporous carbons have attracted much attention for micromolecule gas separation and accumulation owning to their superior adsorption potential and surface polarizability. However, to prepare N-doped microporous carbon usually acquire excess corrosive KOH as activator, which limits its application in industry. Here, we propose a non-corrosion method for the manufacture of narrow N-doped microporous carbons using potassium citrate acts as activating agent, and urea acts as both a nitrogen doping agent and coactivator without any solvent. The BET surface area, micropore volume, pore size distribution and N content can be easily adjusted by changing the potassium citrate/urea ratio and activating temperature. The influence of porous structure and N content on CH4 uptake and separation was investigated, and ultra-micropore volume (<1nm) plays a dominate role in CH4 selectivity adsorption. ACK2N1 had the largest CH4 adsorption capacity of 3.00 mmol/g and CH4/N2 selectivity of 7.11 at 273.15 K and 100 KPa due to its largest ultra-micropore volume and N content. The adsorption breakthrough, regeneration experiments and adsorption thermodynamics showed that the prepared well-developed N-doped microporous carbons have very good potential for CH4 separation and enrichment from low coal bed methane. Furthermore, the pore formation mechanism of the well microporous carbon materials is proposed.

In Situ Construction of Nitrogen-Doped and Zinc-Confined Microporous Carbon Enabling Efficient Na+-Storage Abilities.

Benefiting from the additional active sites for sodium-ion (Na+) adsorption and porous architecture for electrolyte accessibility, nitrogen-doped porous carbon has been considered the alternative anode material for Na+-storage applications. In this study, nitrogen-doped and zinc-confined microporous carbon (N,Z-MPC) powders are successfully prepared by thermally pyrolyzing the polyhedral ZIF-8 nanoparticles under an argon atmosphere. Following the electrochemical measurements, the N,Z-MPC not only delivers good reversible capacity (423 mAh/g at 0.02 A/g) and comparable rate capability (104 mAh/g at 1.0 A/g) but also achieves a remarkable cyclability (capacity retention: 96.6% after 3000 cycles at 1.0 A/g). Those can be attributed to its intrinsic characteristics: (a) 67% of the disordered structure, (b) 0.38 nm of interplanar distance, (c) a great proportion of sp2-type carbon, (d) abundant microporosity, (e) 16.1% of nitrogen doping, and (f) existence of sodiophilic Zn species, synergistically enhancing the electrochemical performances. Accordingly, the findings observed here support the N,Z-MPC to be a potential anode material enabling exceptional Na+-storage abilities.

Highly Microporous Nitrogen-Doped Carbon Derived from Silicon Oxycarbide Ceramics for Supercapacitor Application

Highly Microporous Nitrogen-Doped Carbon Derived from Silicon Oxycarbide Ceramics for Supercapacitor Application

MOF-Based Co and Mn Embedded in Nitrogen-Doped Microporous Carbon as an Efficient Catalyst for Oxygen Reduction Reaction in Anion Exchange Membrane Fuel Cell

Developing a low-price, high catalytic activity, and strong durability electrocatalyst for alkaline oxygen reduction reaction (ORR) is significantly important for anion exchange membrane fuel cell (AEMFC). Herein, Co and Mn salts were added into ZIF-8 to obtain CoMn-ZIF-Ac-2. Co and Mn embedded in nitrogen-doped microporous carbon (CoMn-N-C-Ac-2-Ts, T = 700 , 800, 900, and 1000°C) were obtained by carbonizing CoMn-ZIF-Ac-2 at various temperature. The influence of various pyrolysis temperature and molar ratios between Co and Mn toward ORR catalytic activity was researched. For CoMn-N-C-Ac-2-Ts, CoMn-N-C-Ac-2-800 had the highest ORR catalytic activity with the half-wave potential of 0.875 V in 0.1 M KOH, only 5 mV lower than that of 20 wt % Pt/C. Besides, high 4e- selectivity, excellent stability (retaining 100% for 20 h at 0.6 V vs. RHE), and methanol tolerance are also exhibited. In addition, CoMn-N-C-Ac-2-800 exhibited better ORR activity than Mn-N-C-Ac-800 and Co-N-C-Ac-800, which was attributed to more Co-N4, more MnIII species, and higher surface area. Moreover, the AEMFC based on the CoMn-N-C-Ac-2-800 cathode catalyst obtained a maximal power density of 291 mW·cm-2, which was 78% of the P max achieved with 20 wt % Pt/C (375 mW·cm-2). The highest ORR performance for CoMn-N-C-Ac-2-800 was contributed by the highest defect degree, the most amounts of Co/Mn-N4 active site, the maximum BET surface area, and micropore structure.

Multiple active cobalt species embedded in microporous nitrogen-doped carbon network for the selective production of hydrogen peroxide

To obtain excellent electrocatalysts for improving H2O2 yield and selectivity, we formulated a novel method for embedding cobalt catalytic active sites in porous two-dimensional nitrogen-doped carbon network (CNy) network and employed them as excellent two-electron oxygen reduction reaction (2e−-ORR) electrocatalysts. The polymeric cobalt-based metal–organic framework (polyCo-MOF) and melamine–cyanuric acid–complex (MCA) hybrid (denoted as polyCo-MOF@MCA) was used as a precursor for preparing a series of electrocatalysts comprising multiple active sites such as metallic Co, CoOx, or Co-N, which are homogeneously embedded in the porous two-dimensional CNy network through pyrolysis at high temperatures (600 °C, 700 °C, and 800 °C) under N2 atmosphere. The obtained CoOx/Co@CNy,700 hybrid by pyrolyzing polyCo-MOF@MCA at 700 °C displayed remarkably high H2O2 production and large selectivity in an alkaline solution. The possible catalytic mechanism of CoOx/Co@CNy,700 toward 2e−-ORR was identified by determining the catalytic kinetics and control experiments. The cathode assembled with the CoOx/Co@CNy,700 hybrid showed the maximum H2O2 production of 405 mmol L−1gcat.−1h−1 with a high Faradaic efficiency of 88.9 % at 0.65 V. The present work demonstrated a novel strategy for identifying excellent electrocatalysts with homogeneously dispersed multiple active sites and high production and selectivity for H2O2 synthesis, extending the applications of porous organic frameworks to the field of clean energy.

Tin Nanoclusters Confined in Nitrogenated Carbon for the Oxygen Reduction Reaction.

The oxygen reduction reaction is essential for fuel cells and metal-air batteries in renewable energy technologies. Developing platinum-group-metal (PGM)-free catalysts with comparable catalytic performance is highly desired for cost efficiency. Here, we report a tin (Sn) nanocluster confined catalyst for the electrochemical oxygen reduction. The catalyst was fabricated by confining 1-1.5 nm sized Sn nanoclusters in situ in microporous nitrogen-doped carbon polyhedra (SnxNC) with an average pore size of 0.7 nm. SnxNC exhibited high catalytic performance in acidic media, including positive onset and half-wave potentials, comparable to those of the state-of-the-art Pt/C and far exceeding those of the Sn single-atom catalyst. Combined structural and theoretical analyses reveal that the confined Sn nanoclusters, which have favorable oxygen adsorption behaviors, are responsible for the high catalytic performance, but not Sn single atoms.

Epoxy coated melamine-foam used to synthesize nitrogen-doped microporous carbon for super-capacitive energy storage

The epoxy is cured on the high nitrogen-containing melamine foam to construct a composite of epoxy@melamine-foam. Nitrogen doped porous carbon is synthesized by using the composite as a precursor. The atomic content of nitrogen of the resulting amorphous carbon is determined to be 3.6 at.%. The carbon has a typical microporous structure with a specific surface area of 1675 m2 g−1 and a pore volume of 0.81 cm3 g−1. In a three-electrode system in the basic aqueous electrolyte, a specific capacitance of 292.3 F g−1 is achieved from the electrode loaded with the nitrogen-doped electroactive carbon at a current density of 1 A g−1. In a symmetrical two-electrode system in the same electrolyte, a single electrode displays a specific capacitance of 265.3 F g−1 at 0.5 A g−1. For a simulated supercapacitor device, a specific energy of 8.5 W h kg−1 is obtained at the specific power of 103.3 W kg−1. Findings demonstrate the nitrogen doped microporous carbon can be used as a promising electrode material for supercapacitors.

Nitrogen-doped microporous carbon materials derived from DBU-modified carboxylic acid polymers for CO2 capture

Nitrogen-doped microporous carbon materials were fabricated by carbonization of 1,8-diazabicyclo[5.4.0]undec-7-ene modified carboxylic acid polymers (PDA-DBU) without extra additional activators. The introduction of DBU could not only increase surface nitrogen content that enhanced the alkaline adsorption sites of carbon material itself, but also improved its specific surface area and pore volume. Therefore, CO2 capture capacity of the nonactivated porous carbon (PDA-DBU-800) was 2.98 mmol·g−1 under 1 bar at 25 °C and the CO2 adsorption selectivity based on the IAST adsorbed solution theory was 27.3 (CO2/N2 =85:15). Meanwhile, the dynamic breakthrough experiment further confirmed that PDA-DBU adsorbent exhibited good selective adsorption capacity for CO2. Furthermore, PDA-DBU owned a great stability and reusability. The microporous carbon materials derived from DBU-modified carboxylic acid polymers will be a potential candidate for CO2 capture.

Cobalt nanoparticles supported on microporous nitrogen-doped carbon for an efficient catalytic transfer hydrogenation reaction between nitroarenes and N-heterocycles

Cobalt nanoparticles supported on microporous nitrogen-doped carbon (Co/mNC) were prepared for catalytic hydrogen transfer between nitroarenes and N-heterocycles.

Microporous nitrogen-doped carbon from polyaniline as a highly efficient and stable catalyst for acetylene hydrochlorination

BackgroundAs a hot alternative to toxic industrial catalyst for acetylene hydrochlorination recently, N-doped carbon material (NC) catalysts have not yet exhibited both good activity and stability. MethodsHerein, NC catalysts with special physicochemical characteristics (abundant specific surface area and proper nitrogen content) were presented by the calcination of protonated polyaniline via chemical polymerization conditions. Significant FindingsA comparison of the performance between the novel catalysts and industrial 5% HgCl2/AC catalyst for acetylene hydrochlorination was evaluated under same acetylene gas hourly space velocity condition. The P-NC-1173-A6V12 catalyst exhibited a better initial acetylene conversion as well as stability at a high temperature reaction condition. The excellent catalytic stability is improved by the synergetic effect of abundant pore structure (especially micropores) and proper nitrogen species. In addition, carbon deposition is the main deactivation reason of catalyst. This work provides a facile method to prepare an environmentally friendly non-metallic catalyst with the potential for acetylene hydrochlorination.

Nitrogen-Doped Microporous Carbon Prepared by One-Step Carbonization: Rational Design of a Polymer Precursor for Efficient CO2 Capture

Nitrogen-doped microporous carbon using carboxylic acid-functionalized imidazole-type polymers (PDVA) as a carbon precursor was fabricated by a one-step carbonization method without an additional activator. The introduction of acrylic acid was beneficial to promote the formation of microporous structures during the pyrolysis process. By changing the carbonization temperature, the textural properties and surface nitrogen content of the carbon materials were tuned. The synergistic effect of the microporous structure and basic nitrogen sites was conducive to enhancing the CO₂ adsorption performance of porous carbon materials. The CO₂ adsorption quantity of PDVA-C-800 obtained without an additional activator reached 3.18 mmol·g–¹ under 1 bar at 25 °C, which was comparable to that of the reported carbon materials. Besides, PDVA-C-800 possessed excellent cycle stability and recyclability. The fabrication of microporous nitrogen-doped carbon derived from carboxylic acid-functionalized imidazole-type polymers provided an original idea for CO₂ uptake.