Nitrogen-doped Porous Carbon Research Articles

CO-tolerant heterogeneous ruthenium catalysts for efficient formic acid dehydrogenation.

The development of improved and less costly catalysts for dehydrogenation of formic acid (HCOOH) is of general interest for renewable energy technologies involving hydrogen storage and release. Theoretical calculations reveal that ruthenium (Ru) nanoparticles supported on nitrogen-doped carbon should be appropriate catalysts for such transformations. It is predicted that nitrogen doping significantly decreases the formation of CO, but at the same time increases CO tolerance of the catalysts. To prove these hypotheses heterogeneous ruthenium catalysts supported on porous nitrogen-doped carbon (Rux/CN) with hierarchical structure were synthesized using carbon nitride (C3N4) as template and phenanthroline (Phen) as ligand. Experimental tests in HCOOH dehydrogenation revealed the optimal catalyst Ru7/CN exhibiting good thermal stability and a high turnover frequency (TOF > 1300 h-1), which is more than one order of magnitude higher than that of the commercial Ru5/C catalyst.

Nitrogen-doped Porous Carbon Supported Nickel Catalysts for Efficient Hydrodeoxygenation of Lignin-derived Vanillin to 2-methoxy-4-methylphenol in Ethanol

Driven by the urgent global demand for clean energy, the catalytic conversion of renewable lignin biomass has attracted widespread attention. In this work, we proposed a two-step method for synthesizing nickel-supported nitrogen-doped porous carbon catalyst (Ni/NPC) for the in-situ hydrodeoxygenation (HDO) of lignin-derived vanillin (VAN) to 2-methoxy-4-methylphenol (MMP). The process involved co-hydrothermal treatment and pyrolysis of a mixture containing feedstocks and ZnCl2 activator, with simultaneous N doping and pore construction. Under optimal conditions of 0.4MPa N2 at 220 ℃ for 4h, the Ni/NPC achieved 99.13% conversion of VAN and 97.32% yield of MMP using ethanol as a hydrogen donor. The enhanced catalytic activity was attributed to the synergistic effect of Ni metal sites and N doping, and efficient pore activation of ZnCl2. In addition, the Ni/NPC maintained relatively stable activity over four cycles. This cost-effective and simple synthesis method, coupled with the high activity of the catalyst, presents a viable strategy for upgrading lignin derivatives into high-value chemicals in the H2-free HDO process.

Synergistic mechanisms of nitrogen configurations in sulfur hosts and their enhancement of electrochemical performance in lithium‑sulfur batteries

Lithium‑sulfur batteries (LSBs) have attracted a lot of attention due to their high theoretical capacity and energy density. However, the cathode material for LSBs is limited by the low conductivity of sulfur and its products, as well as volume fluctuations during charging and discharging, and the shuttle effect of soluble lithium polysulfide. In this work, a cathode sulfur host material Nitrogen-doped porous carbon materials (N-PCM) was synthesized, doped with Pyridine N and Pyrrolic N, using melamine and glycine as nitrogen sources, silicon dioxide as template. The synthesis method characterized by controllable nitrogen content and nitrogen configurations. The results of the electrochemical performance test indicate that the composite N-PCM/S exhibits a higher capacity and enhanced cycling stability. At a rate of 0.1C, N-PCM/S demonstrates an initial discharge capacity of up to 1308 mAh/g. At 2C, the initial discharge capacity is 603 mAh/g, while maintaining a reversible capacity of 543 mAh/g after 400 cycles. The capacity decay rate is only 0.025 % per cycle, showcasing excellent cycle stability. Additionally, the N-PCM/S exhibits excellent electrochemical performance under electrolyte-poor conditions. The results showed that the synergistic effect of different nitrogen configurations significantly enhanced the adsorption and catalytic conversion of polysulfide by sulfur hosts, accelerate the reaction rate of polysulfide.

FeNi/Ni2P nanoparticles encapsulated in nitrogen-doped porous carbon: efficient electrocatalysts for oxygen evolution reaction

FeNi/Ni2P nanoparticles encapsulated in nitrogen-doped porous carbon: efficient electrocatalysts for oxygen evolution reaction

Elucidating the efficacious capacitive deionization defluorination behaviors of heteroatom-doped hierarchical porous carbon nanofibers membrane

Heteroatom-doped porous carbons, particularly those incorporating nitrogen functionalities, demonstrate exceptional electrochemical properties advantageous for capacitive deionization (CDI) defluorination. Nevertheless, the underlying mechanism of fluoride removal remains inadequately understood, warranting comprehensive investigation to facilitate the practical implementation of CDI technology. Herein, a novel nitrogen-doped hierarchical porous carbon nanofiber membrane (HPCNM) derived from a hydrochloric acid etched FeNi3@CNFs (FeNi3 alloy encapsulated within carbon nanofibers) network was reasonably designed and synthesized for CDI defluorination. The HPCNM electrode exhibited superior defluorination capabilities, attributed to its distinctive hierarchical porosity and compositional architecture. The novel material achieves remarkable performance metrics, including a defluorination capacity of 58.38 mg g−1, rapid ion removal kinetics (0.97 mg g−1 min−1), and maintained efficiency throughout 20 operational cycles. Density functional theory (DFT) calculations indicate that nitrogen-doped carbon (NC) preferentially adsorbs fluoride, exhibiting the lowest adsorption energy. Fluoride interacts with NC through a combination of weak covalent bonds and van der Waals forces. Its inherent electronegativity, hardness, and high electrophilicity index, contrasted with low softness and nucleophilicity, facilitate the selective adsorption. Furthermore, an optimized NC electrode, operating at 1.2 V in simulated industrial wastewater, achieved fluoride removal compliant with national standards, demonstrating its practical applicability for treating contaminated effluent. These findings advance the understanding of selective fluoride removal, contributing to the development of targeted electrodes for industrial applications.

A Bifunctional Iron-Nickel Oxygen Reduction/Oxygen Evolution Catalyst for High-Performance Rechargeable Zinc-Air Batteries.

Efficient and robust electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for fuel cells, metal-air batteries, and other energy technologies. Here, a highly stable, efficient bifunctional OER/ORR electrocatalyst (FeNi-NC@MWCNTs) is reported and demonstrated its integration and robust performance in an aqueous Zinc-air battery (ZAB). The catalyst is based on neighboring iron/nickel sites (FeNiN6) which are atomically dispersed on porous nitrogen-doped carbon particles. The particles are wrapped in electrically conductive multi-walled carbon nanotubes for enhanced electrical conductivity. Electrocatalytic analyses show high OER and ORR performance (OER/ORR voltage difference = 0.69V). Catalyst integration in a ZAB results in excellent performance metrics, including an open circuit voltage of 1.44V, a specific capacity of 782 mAh g-1 (at j = 15mA cm-2), a peak power density of 218mW cm-2 (at j = 260mA cm-2) and long-term durability over 600 charge/discharge cycles. Combined experimental and theoretical (density functional theory) analyses provide an in-depth understanding of the physical and electronic structure of the catalyst and the role of the FeNi dual atom reaction site. The study therefore provides critical insights into the structure and reactivity of high-performance bifunctional OER/ORR catalysts based on atomically dispersed non-critical metals.

Constructing interconnected hierarchical porous structures and nitrogen-doped carbon nanofibers for superior capacitive deionization

Capacitive Deionization (CDI) has emerged as a sustainable and efficient method for desalinating low-salinity water sources. However, CDI materials are often limited by insufficient surface area, slow electron/ion transport, and suboptimal electrolyte wettability, which restrict desalination capacity and rate. Herein, we simultaneously construct interconnected hierarchical porous structures and nitrogen-doping in carbon nanofibers by pyrolyzing polymer nanofiber precursors embedded with Zeolite Imidazolate Framework-8 (ZIF-8) nanoparticles. ZIF-8 nanoparticles serve not only as precise pore-forming templates but also act as a rich source of nitrogen for doping the carbon nanofibers. We optimize the pore structure and nitrogen content of the carbon nanofibers by tuning the diameter of ZIF-8 nanoparticles within the polymer nanofiber precursor, thereby achieving superior CDI performance. This unique structure not only substantially increases the specific surface area and significantly enhances mass transfer processes, but also introduces abundant nitrogen into the porous carbon fibers. This improves their hydrophilicity, adjusts their electronic structure, increases active sites, and greatly boosts the electrodes’ adsorption capacity and desalination efficiency. An electrode constructed from the optimized porous nanofibers with a larger specific surface area (LPCNF) achieves a peak desalination capacity of 68.11 mg/g. Furthermore, the electrode maintains a high salt adsorption capacity (SAC) retention of 93.4 % after 50 cycles, significantly outperforming conventional materials such as activated carbon, graphene, and carbon nanotubes. Overall, the developed method optimizes both the pore structure and enhances the nitrogen content, providing a novel strategy for developing high-performance CDI electrode materials.

Introducing yttrium into Pt-based intermetallic compounds induce electron perturbation and anti-oxidation for enhancing oxygen reduction activity and durability

Pt-based intermetallic compounds (IMCs) as competitive electrocatalysts for oxygen reduction reaction (ORR) still face problems of surface oxidation and transition metal (M) dissolution in harsh electrochemical environments. Here, we report a strategy to induce electronic perturbation in IMCs by introducing yttrium (Y) to further regulate Pt d-band filling and alloy stability, and Y-doped PtCo IMCs supported on π-electron-rich nitrogen-doped porous carbon (Y-PtCo/NPPC) are presented as a proof of concept. X-ray absorption fine structure (XAFS) reveals that the introduced Pt-O-Y configuration in PtCo IMCs allows the Pt 5d orbital occupancy to be increased, which enhances the anti-oxidation ability of Pt atoms and further stabilizes the internal Co atoms. Y-PtCo/NPPC exhibits satisfactory ORR activity with a high mass activity (MA) of 1.89 A mgPt-1 and is much higher than that of the Pt/C catalyst (0.19 A mgPt-1). In particular, the MA retention of up to 84.7 % is maintained after 30,000 cycles accelerated durability test (ADT), and the Co atom dissolution ratio decreased by 6.4 times compared to PtCo/NPPC. Impressively, the Y-PtCo/NPPC catalyst achieves a high peak power density (1.0 W cm−2) in proton exchange membrane fuel cell (PEMFC) (H2-air). Theoretical calculations have also demonstrated that the introduction of Y element shifts Pt d-band downward, weakening the adsorption of oxygen-containing intermediates. The improved stability stems from the enhancement of the vacancy formation energies of Pt and Co.

Hybrid Particle Size Template Method for Controllable Synthesis of Nitrogen-Doped Multilevel Porous Carbon as High-Rate Zn-Ion Hybrid Supercapacitor Cathode Materials.

Achieving high rate performance without compromising energy density has always been a critical objective for zinc-ion hybrid supercapacitors (ZHSCs). The pore structure and surface properties of carbon cathode materials play a crucial role. We propose utilizing a hybrid particle size (20 and 40 nm) magnesium oxide templates to regulate the pore structure of nitrogen-doped porous carbon derived from the soybean isolate. The multilevel pore structure enhanced ion transport efficiency while also improving the utilization of micropores. Nitrogen doping and oxygen-containing functional groups enhanced the wettability of carbon materials with aqueous electrolytes and facilitated the chemisorption of Zn2+ on the carbon material surface. The nitrogen-doped multilevel porous carbon material (HT-NMPC-1/1) prepared with a 1 : 1 mass ratio of the two templates exhibited a specific capacity of 146.65 mAh g-1 at 0.2 A g-1. Moreover, the Swagelok cells assembled with HT-NMPC-1/1 and Zn foil achieved a high energy density of 121.5 W h kg-1, high power output of 166 W kg-1, and 93.09 % capacity retention after 8000 cycles at 2 A g-1. Therefore, HT-NMPC-1/1 is a highly promising candidate for ZHSCs cathode materials. Furthermore, the novel pore regulation strategy and straightforward preparation method offer valuable reference points for other porous carbon-based functional materials.

Fabrication of Ultrahigh-Loading Dual Copper Sites in Nitrogen-Doped Porous Carbons Boosting Electroreduction of CO2 to C2H4 Under Neutral Conditions.

Synthesis of high-loading atomic-level dispersed catalysts for highly efficient electrochemical CO2 reduction reaction (eCO2RR) to ethylene(C2H4) in neutral electrolyte remain challenging tasks. To address common aggregation issues, a host-guest strategy is employed, by using a metal-azolate framework (MAF-4) with nanocages as the host and a dinuclear Cu(I) complex as the guest, to form precursors for pyrolysis into a series of nitrogen-doped porous carbons (NPCs) with varying loadings of dual copper sites, namely NPCMAF-4-Cu2-21 (21.2 wt%), NPCMAF-4-Cu2-11 (10.6 wt%), and NPCMAF-4-Cu2-7 (6.9 wt%). Interestingly, as the loading of dual copper sites increased from 6.9 to 21.2 wt%, the partial current density for eCO2RR to yield C2H4 also gradually increased from 38.7 to 93.6 mA cm-2. In a 0.1 m KHCO3 electrolyte, at -1.4 V versus reversible hydrogen electrode (vs. RHE), NPCMAF-4-Cu2-21 exhibits the excellent performance with a Faradaic efficiency of 52% and a current density of 180 mA cm-2. Such performance can be attributed to the presence of ultrahigh-loading dual copper sites, which promotes C─C coupling and the formation of C2 products. The findings demonstrate the confinement effect of MAF-4 with nanocages is conducive to the preparation of high-loading atomic-level catalysts.

Electrocatalytic oxygen reduction on nitrogen-doped porous carbon spheres prepared with resorcinol–phenolsulfonic acid–formaldehyde mixed resins

Abstract The resorcinol–phenolsulfonic acid–formaldehyde (RxPS1–xF) mixed resin spheres were prepared by the high-temperature hydrothermal synthesis. Pyrolysis of the resin spheres under NH3 atmosphere produced small, porous, conductive N-doped carbon spheres. These carbon spheres promoted electrocatalytic oxygen reduction reaction (ORR) with almost 100% four-electron reduction selectivity, and their performance was comparable to that of the state-of-the-art Pt/C catalyst.

Nitrogen and Sulfur Doped Porous Carbon Sheet with Trace Amount of Iron as Efficient Polysulfide Conversion Catalyst for High Loading Lithium-Sulfur Batteries.

The major challenges in enhancing the cycle life of lithium-sulfur (Li-S) batteries are the polysulfide (PS) shuttling and sluggish reaction kinetics (S to Li2S, Li2S to S). To alleviate the above issues use of hetero atom doped carbon as cathode host matrix is a low-cost and efficient approach as it works as a dual-functional framework for PS anchoring as well as electrocatalyst for faster redox kinetics. Here, the dual role of the Fe-containing heteroatom-doped carbon sheets (CS) in chemisorption of Li2S6 and catalyzing its faster conversion to Li2S is established through UV-Vis, XPS and CV studies. To substantiate the catalytic effect composite cathodes were prepared by encapsulating sulfur in CS which is further blended with carbon nanotubes (CNTs) to form free-standing cathode. The electrochemical performance of the three cathodes viz., S@Fe-N-CS-CNT, S@Fe-S-CS-CNT and S@Fe-NS-CS-CNT were evaluated by constructing Li-S cells. Among all, the S@Fe-NS-CS-CNT delivers a high initial discharge capacity of 1017 mAh g-1 at 0.5 C rate and sustains 751 mAh g-1 capacity after 260 cycles with a capacity retention of 73.8 %. Even at high S-loading (12 mg cm-2), it delivers an initial discharge capacity of 892 mAh g-1 and it retained 575 mAh g-1 after 200 cycles.

Unraveling the promotive mechanism of nitrogen-doped porous carbon from wasted lignin for Cr (VI) removal

Persistent environmental pollution by heavy metals, particularly Cr (VI), poses significant risks to ecosystems and human health due to its high toxicity and bioaccumulation potential. The development of high-performance, cost-effective adsorbents from sustainable materials remains a critical challenge in the field of Cr (VI) remediation. This study investigates the influence of pyrrolic-N (N-5) within nitrogen-doped hierarchical porous carbon (N-HPC) on its adsorption capacity. Results indicate that N-HPC variants with a higher N-5 content exhibit superior adsorption abilities. The optimal sample demonstrated an exceptional adsorption capacity of 386.2 mg/g for Cr (VI). Even after seven regeneration cycles, this N-HPC variant maintained a remarkable 77.8 % removal efficiency for Cr (VI), highlighting its robust stability and selectivity. The relationship between the physicochemical properties of N-5 and N-HPC was thoroughly examined, revealing that N-5 plays a crucial role in the adsorption process. Due to its high electronegativity, nitrogen-doping into the carbon framework generates a dipole moment, enhancing the electronegativity of N-HPC, altering its local electron density and polarity, increasing specific surface area, carbon defect density, and ion exchange capacity. These factors collectively contribute to significant improvements in pore filling, ion exchange efficiency, and electrostatic adsorption by N-HPC. The reduction complexation mechanism emerges as the dominant factor in the adsorption process. N-5 not only provides reducing electrons as an electron donor, facilitating the continuous conversion of Cr (VI) to Cr (III), but also acts as an adsorption active site, complexing Cr to the surface of N-HPC. This synergistic effect strengthens the reduction complexation, enhances adsorption performance, and improves the regeneration cycle and adsorption selectivity for Cr.

A two-pronged strategy to boost the capacitive deionization performance of nitrogen-doped porous carbon nanofiber membranes

Carbon-based capacitive deionization (CDI) systems are universally subject to the limited desalination capacity, due to the electrosorption characteristics and undesirable pore structures. Herein, a two-pronged strategy is proposed to boost the desalination performance of the electrospun carbon nanofibers (CNFs), where silicalite-1 nanoparticles as the internal porogen create mesopores and macropores, and layered zeolitic imidazolate framework (ZIF-L) leaves as the external carbon source provide micropores and mesopores. This combination results in the large surface area, well-developed graded pore structure, and increased nitrogen content of the core-shell polyacrylonitrile/silicalite-1@ZIF-L-derived CNFs (defined as PCNFs-SZ) electrode, which delivers a superior specific capacitance of 145.4 F g−1 in a neutral electrolyte. The symmetric CDI cell assembled by the self-supporting PCNFs-SZ membrane electrodes holds a prominent desalination capacity of 37.09 mg g−1 and a rapid salt removal rate of 10.36 mg g−1 min−1 at 1.2 V (initial NaCl concentration: 500 mg L−1), and demonstrates significant potential for real-world applications in the desalination and purification of reclaimed water. Furthermore, theory calculations confirm the enhanced Na+-capture capability of PCNFs-SZ. The present work highlights an effective and viable approach to enhance the desalination performance of carbon-based CDI cells.

Tailoring-Orientated Deposition of Li2S for Extreme Fast-Charging Lithium-Sulfur Batteries.

Precipitation/dissolution of insulating Li2S has long been recognized as the rate-determining step in lithium-sulfur (Li-S) batteries, which dramatically undermines sulfur utilization at elevated charging rates. Herein, we present an orientated Li2S deposition strategy to achieve extreme fast charging (XFC, ≤15 min) through synergistic control of porosity, electronic conductivity, and anchoring sites of electrode substrate. Via magnesiothermic reduction of a zeolitic imidazolate framework, a nitrogen-doped and hierarchical porous carbon with highly graphitic phase was developed. This design effectively reduces interfacial resistance and ensures efficient sequestration of polysulfides during deposition, leading to (110)-preferred growth of Li2S nanocrystalline between (002)-dominated graphitic layers. Our approach directs an alternative Li2S deposition pathway to the commonly reported lateral growth and 3D thickening growth mode, ameliorating the electrode passivation. Therefore, a Li-S cell capable of charging/discharging at 5C (12 min) while maintaining excellent cycling stability (82% capacity retention) for 1000 cycles is demonstrated. Even under high S loading (8.3 mg cm-2) and low electrolyte/sulfur ratio (3.8 mL mg-1), the sulfur cathode still delivers a high areal capacity of >7 mAh cm-2 for 80 cycles.

Cascade Reactions for Enhanced CO2 Capture: Concurrent Optimization of Porosity and N‐Doping

AbstractCarbon capture emerges as a pivotal decarbonization technology for addressing global warming challenges. Porous carbons, despite their cost‐effectiveness and ease of regeneration for CO2 capture, typically exhibit limited capacity owing to insufficient adsorption sites. Here, nitrogen‐doped porous carbons (NPCs) are introduced that overcome the prevalent trade‐offs between specific surface area and N‐doped content in NPCs fabrication through cascade reactions. The optimized NPC, which features hierarchical porosity ranging from ultra‐micropores to macropores, shows a superior CO2 capture capacity of 4.46 mmol g−1, ranking in the top 10% of the reported NPCs. This capacity exceeds that of the NPC fabricated with the conventional method by 58% and surpasses the control porous carbon by 106%. Langmuir adsorption modeling and mathematic correlation analysis revealed that this enhanced capacity is attributed to significantly improved ultra‐micropores volume and nitrogen‐species content. Moreover, this optimized NPC demonstrates exceptional stability, preserving its adsorption performance over 110 adsorption–desorption cycles under simulated flue gas conditions. This research not only highlights the integration of templating and N‐doping within NPCs fabrication but also offers an effective strategy to optimize porosity and nitrogen functionality in carbon materials, advancing beyond conventional methodologies.

Regulating the Performance of CO2 Adsorbents Based on the Pyrolysis Mechanism of Self-Sacrificial Templating Agents.

Previous research has proven that the pore shape and nitrogen group content of adsorbents play essential roles in determining their carbon dioxide (CO2) adsorption performance. In this article, a series of nitrogen-doped porous carbon materials were prepared for CO2 adsorption by varying the proportion of carbon nitride, the pyrolysis temperature, and the activation ratio of KOH, using chitosan as the carbon source, carbon nitride (g-C3N4 and g-C3N5) as self-sacrificing templating agents, and KOH as the activator. Among the prepared materials, T6-850-1 has the highest specific surface area (SBET) of 2336 m2/g, and T6-750-1 has the highest microporous area (Smicro) and CO2 adsorption capacity (1 bar, 298 K) of 1969 m2/g and 3.49 mmol/g, respectively. The thermal decomposition temperature and products of carbon nitride templates were characterized and tested by thermogravimetric infrared gas chromatography-mass spectrometry (TG-IR-GC-MS), and the thermal decomposition mechanisms of the two carbon nitride templates were investigated. We found that the thermal stability of the template directly affects the pore structure of the final sample as well as the type and quantity of nitrogen species.

Selenic Acid Etching Assisted Atomic Engineering for Designing Metal-Semimetal Dual Single-Atom Catalysts for Enhanced CO2 Electroreduction.

Single-atom catalysts are promising for electrocatalytic CO2 conversion but face challenges in controllable syntheses. Herein, a facile selenic acid etching-assisted strategy has been developed to fabricate a hybrid metal-semimetal dual single-atom catalyst for electrocatalytic CO2 reduction. This strategy enables the simultaneous generation of monodisperse active sites and hierarchical morphologies with hollow nanostructures. The as-obtained catalyst with Fe-Se dual single-atom sites supported by porous nitrogen-doped carbon (FeSe-NC) shows exceptional catalytic activity and CO selectivity, delivering a Faradaic efficiency (FE) of >97% with industrially comparable jCO, superior to the Fe single-atom catalyst. Moreover, the FeSe-NC-based rechargeable Zn-CO2 battery delivers a high power density (2.01 mW cm-2) and outstanding FECO (>90%), as well as excellent cycling stability. Experimental results together with theoretical calculations reveal that the etching-induced defects and the Se-modulated Fe centers with asymmetrical polarized charge distributions synergistically facilitate the key intermediate *CO desorption and thus accelerate the CO2-to-CO conversion.

A “pre-constrained bimetallic” strategy for the preparation of efficient synergistic electrocatalytic hydrogen evolution catalysts

A micro-sized bimetallic nanoparticles (NPs) catalyst that anchors a mixture of Co and Pd atoms onto a porous nitrogen-doped carbon (NC) framework for electrocatalysis of hydrogen evolution reaction (HER). Programmable metal-porphyrin ligands serve as building blocks for attaching bimetallic sites (consisting of Co and Pd) in metal-organic frameworks for decentralized anchoring before pyrolysis. Experimental studies have shown the interaction between Pd and Co in Co20/Pd20-NC results in electron depletion near Co and electron accumulation near Pd, respectively. Therefore, there is an asymmetric local electron density distribution on the bimetallic site of Co20/Pd20-NC, which improves the activity of the catalyst. To achieve a current density of 10mA·cm-2 in both acidic and alkaline conditions, the Co20/Pd20-NC exhibits noteworthy HER characteristics with overpotentials of 23 and 52mV, respectively. The Co20/Pd20-NC prepares in this study which shows good characteristics in the process of electrocatalytic hydrogen evolution, and has a good application prospect.

Adsorptive removal of ppb levels of boron trichloride using N-doped porous carbon materials

The removal of trace boron impurities (BCl3) in chlorosilane represents a significant challenge in polysilicon production. In this study, we employed the high-temperature ammonia etching method to fabricate nitrogen-doped porous carbon (NPC) adsorbents derived from lignite. The as-prepared NPCs were tested and evaluated as potential adsorbents for efficient removal of BCl3. Furthermore, a systematic investigation was conducted to assess the impact of contact time, initial concentration, adsorbent dose, and temperature. It was found that the adsorbent (NPC900) obtained at 900 °C exhibited an excellent efficacy in removing BCl3 (R% = 98.9 %), with a residual concentration of BCl3 in the solution was 1.65 ppb, which met the industrial requirements. This can be primarily attributed to its porous structure and high pyridinic-N content. Furthermore, the adsorption of BCl3 on NPC900 was better followed by Pseudo-second order kinetic model and the Langmuir isotherm model. Thermodynamic studies showed that the adsorption process was spontaneous and exothermic. The interactions between BCl3 and different nitrogen forms was analysis through the utilizing density functional theory (DFT) calculation. The findings indicate that pyridinic-N exhibits a stronger interaction with BCl3 (Eads = −102.35 kJ/mol), primarily due to the easier electron transfer from the nitrogen atom on pyridinic-N to BCl3.