Heteroatom-doped Carbon Materials Research Articles

Boosting capacitive performance of N, S co-doped hierarchical porous lignin-derived carbon via self-assembly assisted template-coupled activation

Heteroatom-doped porous carbon materials show promise for use as supercapacitor electrodes, but the tradeoff between surface area and the heteroatom dopant levels limits the supercapacitive performance. Here, we modulated the pore structure and surface dopants of N, S co-doped hierarchical porous lignin-derived carbon (NS-HPLC-K) via self-assembly assisted template-coupled activation. The ingenious assembly of lignin micelles and sulfomethylated melamine into a magnesium carbonate basic template greatly promoted the KOH activation process, which endowed the NS-HPLC-K with uniform distributions of activated N/S dopants and highly accessible nanosized pores. The optimized NS-HPLC-K exhibited a three-dimensional hierarchically porous architecture composed of wrinkled nanosheets and a high specific surface area of 2538.3 ± 9.5 m2/g with a rational N content of 3.19 ± 0.01 at.%, which boosted the electrical double-layer capacitance and pseudocapacitance. Consequently, the NS-HPLC-K supercapacitor electrode delivered a superior gravimetric capacitance of 393 F/g at 0.5 A/g. Furthermore, the assembled coin-type supercapacitor showed good energy-power characteristics and cycling stability. This work provides a novel idea for designing eco-friendly porous carbons for use in advanced supercapacitors.

Fast joule-heating synthesized heteroatom-doped carbon and its impressive electrochemical performance

To tackle the issues of slow heating/cooling process and underutilization of heat in the traditional electric furnace pyrolysis, a fast Joule-heating pyrolysis is herein reported. The Joule heat generated by applying DC voltage to the left and right flanks of the electrically conductive precursor, viz. carbon fiber cloth supported polyaniline, can turn the precursor into N, S-codoped carbon material within minutes. When the pyrolysis voltage locates between 1.0–6.0 V and lasts for 10 min, the surface temperature field of the precursor resembles quasi-concentric circles, with the highest temperature in the core and gradually decreasing temperature around. A fairly high core temperature close to 600 °C can be achieved by applying a DC voltage of 6.0 V for merely ∼150 s. Only by reaching 4.0 V upwards can the polyaniline be ruptured and then converted to more stable CN and CS groups. The pyrolyzed products of polyaniline present as thin coatings with uniformly distributed C, N, S, O elements on the heat-resistant carbon fiber cloth support. In accordance with comparative studies on the carbon-based electrode derived from traditional electric furnace pyrolysis, fast Joule-heating pyrolysis is found to be a wiser strategy to prepare heteroatom-doped carbon materials with impressive capacitive and electrocatalytic performance.

Boron–Phosphorus Codoped Coral-like Hard Carbon Anodes for Sodium Ion Storage

Hard carbon materials have the advantages of low price, environmental friendliness, and good electrical conductivity but have the disadvantages of unsatisfactory sodium storage capacity and low long-cycle stability. The use of heteroatom doping and structural design can significantly improve the sodium storage properties of carbon materials. In this paper, a boron–phosphorus doped hard carbon material (CABP) was designed by using citric acid as the carbon source. The rich pore structure of CABP also provides fast transport channels for Na+, while the efficient doping of B and P atoms can distort the graphitic layer and generate more active sites and defects. The CABP carbon material therefore exhibits excellent electrochemical properties. It can obtain pretty good capacities of 246.8 mA h g–1 after 400 cycles at 0.1 A g–1. Moreover, it was able to maintain 161.9 mA h g–1 after 5000 cycles at 5 A g–1. This work provides a new route for the facile preparation of high-performance heteroatom-doped carbon materials and an idea for the preparation of diatom-doped materials for energy storage.

Two-dimensional nitrogen and phosphorus co-doped mesoporous carbon-graphene nanosheets anode for high-performance potassium-ion capacitor

Heteroatom-doped carbon materials have high gravimetric potassium-ion storage capability because of their abundant active sites and defects. However, their practical applications toward potassium storage are limited by sluggish reaction kinetics and short cycling life owing to the large ionic radius of K+ and undesirable parasitic reactions. Herein, we report a new strategy that allows for bottom-up patterning of thin N/P co-doped carbon layers with a uniform mesoporous structure on two-dimensional graphene sheets. The highly porous architecture and N/P co-doping properties provide abundant active sites for K+, and the graphene sheets promote charge/electron transfer. This synergistic structure enables excellent K+ storage performance in terms of specific capacity (387.6 mAh g-1 at 0.05 A g-1), rate capability (over 5 A g-1), and cycling stability (70% after 3,000 cycles). As a proof of concept, a potassium-ion capacitor assembled using this carbon anode yields a high energy density of 107 Wh kg-1, a maximum power density of 18.3 kW kg-1, and ultra-long cycling stability over 40,000 cycles.

Three-dimensional porous high boron-nitrogen-doped carbon for the ultrasensitive electrochemical detection of trace heavy metals in food samples.

Exposure to even trace amounts of Cd(II) and Pb(II) in food can have serious effects on the human body. Therefore, the development of novel electrochemical sensors that can accurately detect the different toxicity levels of heavy metal ions in food is of great significance. Based on the principle of green chemistry, we propose a new type of boron and nitrogen co-doped carbon (BCN) material derived from a metal-organic framework material and study its synthesis, characterization, and heavy-metal ion detection ability. Under the optimum conditions, the BCN-modified glassy carbon electrode was studied using square-wave anodic stripping voltammetry, which showed good electrochemical responses to Cd(II) and Pb(II), with sensitivities as low as 0.459 and 0.509 μA/μM cm2, respectively. The sensor was successfully used to detect Cd(II) and Pb(II) in Beta vulgaris var. cicla L samples, which is consistent with the results obtained using inductively coupled plasma-mass spectrometry. It also has a strong selectivity for complex samples. This study provides a novel approach for the detection of heavy metal ions in food and greatly expands the application of heteroatom-doped metal-free carbon materials in detection platforms.

MOF-derived nitrogen-doped porous carbon nanofibers with interconnected channels for high-stability Li+/Na+ battery anodes.

Heteroatom-doped porous carbon materials have been widely used as anode materials for Li-ion and Na-ion batteries, however, improving the specific capacity and long-term cycling stability of ion batteries remains a major challenge. Here, we report a facile based metal-organic framework (MOFs) strategy to synthesize nitrogen-doped porous carbon nanofibers (NCNFs) with a large number of interconnected channels that can increase the contact area between the material and the electrolyte, shorten the diffusion distance between Li+/Na+ and the electrolyte, and relieve the volume expansion of the electrode material during cycling; the doping of nitrogen atoms can improve the conductivity and increase the active sites of the carbon material, can also affect the microstructure and electron distribution of the electrode material, thereby improving the electrochemical performance of the material. As expected, the obtained NCNFs-800 exhibited excellent electrochemical performance with high reversible capacity (for Li+ battery anodes: 1237 mA h g-1 at 100 mA g-1 after 200 cycles, for Na+ battery anodes: 323 mA h g-1 at 100 mA g-1 after 150 cycles) and long-term cycling stability (for Li+ battery anodes: 635 mA h g-1 at 2 A g-1 after 5000 cycles, for Na+ battery anodes: 194 mA h g-1 at 2 A g-1 after 5000 cycles).

Nitrogen-doped porous carbon coated on MnCo2O4 nanospheres as electrode materials for high-performance asymmetric supercapacitors

Spinel-based nanostructured materials are commonly used as promising electrode materials for supercapacitor applications. The combination of heteroatom-doped carbon material with spinel oxides substantially improves the specific capacitance and cyclic stability. In this work, dopamine-derived nitrogen-doped carbon was coated on spinel phase MnCo2O4 nanospheres using simple solvothermal and calcination methods. Surface morphology and the crystalline structure of the prepared MnCo2O4@Nitrogen-doped carbon were confirmed by FESEM and X-ray diffraction. The electrochemical performance of MnCo2O4@Nitrogen-doped carbon electrode material was analyzed by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques. MnCo2O4@nitrogen-doped carbon exhibits the highest specific capacitance of 1200 F/g compared to MnCo2O4 spheres are 726 F/g at 1 A/g and exhibits excellent cyclic stability (capacitance retention of 87% at 7 A/g after 3000 cycles). The enhanced performance of the composite might be benefitted from the synergistic effect between nitrogen-doped carbon on porous MnCo2O4 spheres. Furthermore, an asymmetric supercapacitor device was fabricated by using the optimized composition of MnCo2O4@NC-2 as a positive electrode and nitrogen, sulfur-doped reduced graphene oxide (NS-rGO) as a negative electrode, respectively. This asymmetric supercapacitor device achieves a maximum energy density of 61.0 Wh/kg at a power density of 2889 W/kg and possesses excellent capacitance retention of 95% after 5000 cycles at 7 A/g.

Nitrogen-doped carbon for selective pseudo-metal-free hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran: Importance of trace iron impurity

Heteroatoms-doped carbon materials have recently emerged as effective catalysts for various chemical and electrochemical reactions. The free of metals especially noble metals reduces cost and eliminates issues like sintering or leaching of metals at elevated temperatures in solvents. In this work, selective hydrodeoxygenation (HDO) of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) is for the first time achieved over simple nitrogen-doped carbon (N-C) catalysts. At optimal reaction conditions, a 91% yield of DMF is obtained with excellent catalyst stability. Extensive characterization, including extended X-ray absorption fine-structure (EXAFS) and soft X-ray absorption spectroscopy (sXAS), model reactions, basic data science analysis, and DFT calculations suggest that ppm of Fe in particular FeN3 sites formed in pyrolysis, rather than non-metallic elements, drive key steps such as H2 activation and deoxygenation of –OH during HMF HDO.

Metal-Free Triazine-Based Porous Organic Polymer-Derived N-Doped Porous Carbons as Effective Electrocatalysts for Oxygen Reduction Reaction

In recent years, porous heteroatom-doped carbon materials have been very promising for energy conversion. A newly designed porous organic polymer (POPQ) has been synthesized using two organic monomers, i.e., 2,6-diaminoanthraquinone and cyanuric chloride, under reflux conditions for 72 h in an inert atmosphere. The triazine-containing porous organic polymers undergo pyrolysis, which produces two nitrogen-doped porous carbon materials, N/POPQ600 and N/POPQ800, at 600 and 800 °C temperatures, respectively. Since the resultant N-doped porous materials have a higher surface area than the parent porous organic polymer and the materials have a synergistic effect due to the enriched nitrogen content throughout the matrix, the metal-free N/POPQ600 and N/POPQ800 materials exhibit good electrocatalytic activity toward oxygen reduction reaction (ORR). Among these, the N/POPQ800 material shows excellent ORR activity with a nearly four-electron oxygen reduction pathway where the half-wave potential is estimated to be 0.728 V vs reversible hydrogen electrode (RHE), comparable with the commercially available Pt/C catalyst. Most interestingly, the N/POPQ800 catalyst displays outstanding long-lasting stability. It shows a better methanol tolerance capability than Pt/C, which can be attributed to the high specific surface area and N-doped well-defined crystalline porous structure. Also, the homogeneously distributed active sites throughout the carbon framework are the most precious for the electrochemical oxygen reduction reaction.

Improved U(VI) electrosorption performance of hierarchical porous heteroatom-doped electrode based on double-template method

As an indispensable element in the field of nuclear energy, uranium (U(VI)) is widely concerned because it is abundant and easy to obtain from seawater. Herein, we report a promising dual-template strategy to prepare heteroatom-doped carbon materials with hierarchical micro−/meso−/macroporous from low-cost biomass precursors. The carbon materials with hierarchical porosity nitrogen/oxygen are synthesized through freeze-drying, high-temperature thermal treatment and subsequent HF etching treatment by in-situ growth of SiO2 on the precursor with ethyl silicate as silicon source and introduction of ZnCl2 as hard template and starch/ammonia as carbon and nitrogen source. Based on the advantages of three-dimensional interconnected hierarchical porous heteroatom doping, the electrosorption capacity reaches 67.25 mg/g, and the removal efficiency is as high as 98.45%, when the initial UO2(NO3)2 concentration is 80 mg/L in capacitive deionization. The isothermal adsorption of nitrogen doped hierarchical porous carbon (NHPC) is consistent with the Langmuir model, with a maximum electrosorption capacity of 152.43 mg/g, good cycle stability and high charge efficiency (energy consumption is only 0.77 kg-U kWh−1). Fascinatingly, the initial UO2(NO3)2 concentration is 80 mg/L and it also has a high adsorption capacity in 3.5 wt% NaCl solution, and the U(VI) removal efficiency could reach 42.5% after 8 h of continuous adsorption, with high selectivity. The prepared adsorbent NHPC shows good selectivity for U(VI) in the solution of 11 metal ions co-existing, and the effective selectivity Kd value of U(VI) is 1620.84 mL/g. Finally, X-ray photoelectron spectroscopy analysis reveals that in addition to Coulomb interaction and chelation during the adsorption process, there is also a synergistic effect of the conversion of U(VI) to UO2 under electric drive to improve the adsorption capacity of U(VI).

Sulfur-doped CMK-5 with expanded lattice for high-performance lithium ion batteries

Heteroatom-doped porous carbon materials are very attractive for lithium ion batteries (LIBs) owing to their high specific surface areas, open pore structures, and abundant active sites. However, heteroatom-doped porous carbon with very high surface area and large pore volume are highly desirable but still remain a big challenge. Herein, we reported a sulfur-doped mesoporous carbon (CMK-5-S) with nanotubes array structure, ultrahigh specific surface area (1390 m2/g), large pore volume (1.8 cm3/g), bimodal pore size distribution (2.9 and 4.6 nm), and high sulfur content (2.5 at%). The CMK-5-S used as an anode material for LIBs displays high specific capacity, excellent rate capability and highly cycling stability. The initial reversible specific capacity at 0.1 A/g is as high as 1580 mAh/g and simultaneously up to 701 mAh/g at 1 A/g even after 500 cycles. Further analysis reveals that the excellent electrochemical storage performances is attributed to its unique structures as well as the expanded lattice by sulfur-doping.

Engineering adjacent N, P and S active sites on hierarchical porous carbon nanoshells for superior oxygen reduction reaction and rechargeable Zn-air batteries

Heteroatom-doped carbon materials have been regarded as sustainable alternatives to the noble-metal catalysts for oxygen reduction reaction (ORR), while the catalytic performances still remain unsatisfactory. Herein, we develop a metal-free adjacent N, P and S-codoped hierarchical porous carbon nanoshells (NPS-HPCNs) through a novel layer-by-layer template coating method. The NPS-HPCNs is rationally fabricated by crosslinking of polyethyenemine (PEI) and phytic acid (PA) on nano-SiO2 template surface and subsequently coating of viscous sulfur-bearing petroleum pitch, followed by pyrolysis and alkaline etching. Soft X-ray absorption near-edge spectroscopy (XANES) analysis and density functional theory (DFT) calculations prove the engineering of adjacent N, P and S atoms to generate synergistic and reinforced active sites for oxygen electrocatalysis. The NPS-HPCNs manifests excellent ORR activity with a half-wave potential (E1/2) of 0.86 V, as well as promoted durability and methanol tolerance in alkaline medium. Remarkably, the NPS-HPCNs-based Zn-air battery delivers an open-circuit voltage of 1.479 V, a considerable peak power density of 206 mW cm−2 and robust cycling stability (over 200 h), even exceeding the commercial Pt/C catalyst. This study offers fundamental insights into the construction and synergistic mechanism of adjacent heteroatoms on carbon substrate, providing advanced metal-free electrocatalysts for Zn-air batteries and other energy conversion and storage devices.

An Electrocatalytic Model of the Sulfur Reduction Reaction in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) battery is strongly considered as one of the most promising energy storage systems due to its high theoretical energy density and low cost. However, the sluggish reduction kinetics from Li2 S4 to Li2 S during discharge hinders the practical application of Li-S batteries. Although various electrocatalysts have been proposed to improve the reaction kinetics, the electrocatalytic mechanism is unclear due to the complexity of sulfur reduction reactions (SRR). It is crucial to understand the electrocatalytic mechanism thoroughly for designing advanced electrocatalysts. Herein an electrocatalytic model is constructed to reveal the chemical mechanism of the SRR in Li-S batteries based on systematical density functional theory calculations, taking heteroatoms-doped carbon materials as an example. The adsorption energy of LiSy ⋅ (y=1, 2, or 3) radicals is used as a key descriptor to predict the reaction pathway, rate-determining step, and overpotential. A diagram for designing advanced electrocatalysts is accordingly constructed. This work establishes a theoretical model, which is an intelligent integration for probing the complicated SRR mechanisms and designing advanced electrocatalysts for high-performance Li-S batteries.

In situ oxygen-induced zigzag graphene as metal-free catalyst for hydrogen activation in nitroarenes hydrogenation

Metal-free catalysts for hydrogenation reactions using molecular hydrogen (H2) are a major challenge in the field of catalysis. The Frustrated Lewis Pairs (FLPs) systems and heteroatom-doped carbon materials as metal-free catalysts are currently the mainstream research in hydrogenation reactions. Here, a series of oxygen-induced zigzag graphene (OZG) was constructed over thermal treatment of reduced graphene oxide (rGO) and applied as metal-free catalysts in nitrobenzene hydrogenation. The OZG-800 (thermal treatment at 800 °C) shows promising performance activity with 99.7% nitrobenzene conversion and 94.4% selectivity to aniline. The experimental results indicate that the zigzag edge and medium-strong acid sites formed by oxygen species may be the active centers in nitrobenzene hydrogenation. The density functional theory (DFT) calculations are in accord with experimental results that the zigzag edge and oxygen species play a critical role in H2 activation and dissociation. This work provides a promising route for the rational design of metal-free catalysts for hydrogenation.

Potential dependence of OER/EOP performance on heteroatom-doped carbon materials by grand canonical density functional theory.

Revealing the effect of external applied potential on the reaction mechanism and product selectivity is of great significance in electrochemical studies. In this work, the grand canonical density functional theory method was applied to simulate the explicit electrocatalytic process of oxygen evolution reaction and electrochemical ozone production due to the O3 product sensitivity toward the applied potential. Over the Pt/Pd single atom embedded on B/N co-doped graphene (Pt/Pd-BNC) surface, crossover points of O2/O3 selectivity inversion were predicted to be 1.33 and 0.89V vs standard hydrogen electrode, which were also consistent with the previous experimental results. An in-depth analysis of the energetic terms in the reaction free energies also found the considerable impact of the applied potential on the Helmholtz free energy term, with optimal potential predicted for the key elementary steps, and linear correlations between electrode potential (U) and reaction free energy were found for each elementary step. This study offers extensive knowledge on the potential effect on the O2/O3 selective formation on two-dimensional anode surfaces and provides new insights for investigating the reactivity/selectivity on electrode surfaces in real reaction conditions.

Self-templated synthesis of boron-doped porous carbon by chemical interaction of 2LiBH4·CO2 with CO2

The realization of heteroatom doping can enable carbon functional materials to have superior physiochemical properties via tailoring electron and ion distribution. However, the facile synthesis of heteroatom-doped carbon materials without CO2 emission from precursor is a major challenge for low-carbon utilization of carbon materials. Herein, we report a facile self–templated method to synthesize boron–doped porous carbon derived from CO2 based on the new reactions of 2LiBH4·CO2 with CO2. Boron–doped porous carbon is produced via a consecutive reaction between 2LiBH4·CO2 and CO2. The solid intermediate products with porous structure are formed at the first-step reaction. The newly developed porous solid products serve as the template for the chemical vapor deposition of gaseous intermediate products at the second-step reactions. The self-templated mechanism is demonstrated to form porous templates at initial stage for depositing carbon and boron sources on templates to produce boron-doped porous carbon. As a lithium storage material, it delivers a reversible capacity as high as ∼ 1660 mAh/g at 0.2 A/g and ∼ 890 mAh/g at 1.0 A/g after 1200 cycles. This finding opens a low-carbon and self-templated strategy to synthesize heteroatom–doped carbon functional materials from CO2.

Sulfur Encapsulation and Sulfur Doping Synergistically Enhance Sodium Ion Storage in Microporous Carbon Anodes.

MOF-based materials are a class of efficient precursors for the preparation of heteroatom-doped porous carbon materials that have been widely applied as anode materials for Na-ion batteries. Thereinto, sulfur is often introduced to increase defects and act as an active species to directly react with sodium ions. Although the sulfur introduction and high surface area can synergistically improve capacity and rate capability, the initial Coulombic efficiency (ICE) and electrical conductivity of carbon material are inevitably reduced. Therefore, balancing sodium storage capacity and ICE is still the bottleneck faced by adsorbent carbon materials. Here, sulfur-encapsulated microporous carbon material with nitrogen, sulfur dual-doping (NSPC) is synthesized by postprocessing, achieving the reduced specific surface area by encapsulating sulfur in micropores, and the increased active sites by edge sulfur doping. The synergy between encapsulation and sulfur doping effectively balances specific capacity, rate capability, and ICE. The NSPC material exhibits capacities of 591.5 and 244.2 mAh g-1 at 0.5 and at 10 A g-1, respectively, and the ICE is as high as 72.3%. Moreover, the effect of nitrogen and sulfur on the improvement of electron/ion diffusion kinetics is resonantly demonstrated by density functional theory calculations. This synergistic preparation method may reveal a feasible thought for fabricating excellent-performance adsorption-type carbon materials for Na-ion batteries.

(Invited) Surface Electrochemistry and Physicochemical Behaviors of Carbon and Compound Electrodes in Electrochemical Separation Systems

In recent years, electrochemical separation systems have received a great attention due to their excellent capabilities in environmental remediation, water desalination, and resource recovery. The performances of electrochemical separation systems are often interpreted in terms of capacity and selectivity, both of which are highly dependent on electrode materials. For instance, capacitive deionization (CDI) used for desalination of water employs activated carbon electrodes, as it enables capture and release of sodium chloride in large amounts. In addition, lithium-ion selective electrode such as delithiated LiMn2O4 (i.e. λ-MnO2) or LiFePO4 plays an essential role in selectivity of electrochemical lithium recovery systems. However, although the importance electrode materials cannot be overemphasized for such electrochemical separations, it is also true that we are yet to achieve a sufficient level of understanding on their behaviors in the systems, which is necessary to establish rational electrode-design strategies to enhance capacity and selectivity of the electrochemical separation systems. In this talk, our recent findings on surface electrochemistry of carbon electrodes in electrochemical desalination will be introduced, together with an overview on the non-favorable Faradaic reactions thoroughly characterized with the assistance of various X-ray and electrochemical techniques. Additionally, development of heteroatom-doped carbon material and how it resulted in a highly stable CDI performance will be presented. Moreover, I will talk about our efforts on characterization of physicochemical behavior of λ-MnO2 in electrochemical lithium recovery systems, based on which a significantly higher utilization rate of the electrode materials could be achieved.

HNO3 pre-oxidation-tuned microstructures of porous carbon derived from high-sulfur coal for enhancing capture and catalytic conversion of polysulfides

• N,O,S-multidoped porous carbon was fabricated using a widely available high-sulfur coal. • HNO 3 oxidation increases specific surface area, pore volume, and the defects of NOSTPC. • The S@NOSTPC(O) delivers a high capacity of 645 mAh g −1 at 2C after 200 cycles. • HNO 3 oxidation increases chemical adsorption and conversion of polysulfides together with the catalytic oxidation of Li 2 S. Heteroatoms-doped carbon materials have received increasing interest as promising sulfur hosts for lithium-sulfur (Li-S) batteries. Herein, high-sulfur coal was selected as the low cost and earth-abundant precursor and HNO 3 pre-oxidation was adopted to tune the microstructure of N,O,S-multidoped three-dimensional porous carbon (NOSTPC) to facilitate affinity and conversion toward polysulfides. HNO 3 pretreatment significantly increases the specific surface area, pore volume, and the content of pyrrolic nitrogen and the defects in NOSTPCs. HNO 3 pre-oxidation increases the specific capacity of Li-S battery with NOSTPC as the sulfur host from 559.3 to 860.4 mAh g −1 at 1C, and the capacity retention from 67% to 81% after 200 cycles. The satisfying performance benefits from that oxidation pretreatment improves the chemical adsorption of polysulfides by NOSTPC(O), and accelerates the kinetic conversion of polysulfides together with the catalytic oxidation of Li 2 S. Accordingly, the good performance of high-sulfur coal-based NOSTPCs can not only promote practical application of Li-S batteries, but also facilitate the efficient utilization of high-sulfur coal.

The extended Stӧber method for synthesizing nitrogen-doped porous carbon nanospheres supported Pt nanoparticles towards methanol oxidation in alkaline media

• N -doped porous carbon nanospheres were prepared via the extended Stӧber method. • The NPCs have a high surface area and abundant nitrogen content. • The Pt nanoparticles supported on NPCs showed superior MOR activity and stability. Heteroatom-doped porous carbon materials have emerged as attractive catalyst supports of Pt nanoparticles in the direct methanol fuel cells (DMFCs). Herein, the simple extended Stӧber method towards nitrogen-doped porous carbon nanospheres (NPCs) is reported by polymerizing of 3-aminophenol-formaldehyde (APF) resin spheres. The synthesized NPCs were applied as a carrier for Pt nanoparticles to fabricate the Pt@NPCs catalyst for methanol oxidation. Compared with the commercial Pt/C catalyst, Pt@NPCs showed the larger electrochemically active area (93.6 m 2 g −1 ), higher peak current density (95.91 mA·cm −2 ) and better stability in alkaline media. This improved performance can be attributed to the porous structure of NPCs and nitrogen atoms doped in the carbon matrix increasing the dispersion of the Pt particles on the NPCs catalyst.