GREEN CHEMISTRY
·
2019
·Vol. 21
·期 8
·2129-2137
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IF 9.405
Di Liu,Ping Yang,Hao Zhang,Minjie Liu,Wenfei Zhang,Dongmei Xu,Jun Gao
A non-noble heterogeneous catalyst – a Co, N and C composite encapsulated carbon nanotube grown in situ on the surface of activated carbon (Co–N–C/CNT@AC) – was fabricated via the pyrolysis–reduction process. Co–N–C/CNT@AC catalyzed the reductive coupling of structurally diverse nitroarenes and alcohols to imines and secondary amines under exogenous base- and solvent-free conditions. BET, TEM, SEM, XRD and XPS characterization showed that the exceptional catalytic property of Co–N–C/CNT@AC could be explained by its nanostructure, Co–N and basic N species. Our protocol had advantages of low cost, environment-friendliness, and good applicability. Furthermore, a reaction route of nitroarenes, amines and alcohols as the starting materials was proposed to improve the atom economy of the reductive coupling of nitroarenes with alcohols.
研究领域:
化学
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环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Ruipeng Yuan,Jinyu Zhao,Xu Chen,Xiaoming Qiu,Xiaomin Wang
Cobalt-nitrogen-carbon (CoN x C) materials are regarded as promising low-cost electrocatalysts for the oxygen reduction reaction (ORR). However, their susceptibility to deactivation and poor stability in acidic media limits their practical applications. In this study, we develop cobalt (Co) and manganese (Mn) embedded in nitrogen-doped carbon (CoMnN x C) dual-site catalysts by incorporating Mn into CoN x C and leverage a synergistic dual-catalysis strategy to optimize both activity and stability. The dynamic evolution of *OOH intermediate on the catalyst surface is monitored via in situ Raman spectroscopy, confirming that Mn introduction modulates the reaction pathway. Due to electron transfer from Mn to the Co-N x center in CoMnN x C, *OOH activation on the surface is enhanced, and the two-electron ORR process is inhibited. Consequently, the CoMnN x C catalyst exhibits excellent ORR activity (E 1/2 = 0.76 V vs. reversible hydrogen electrode) and a very low hydrogen peroxide (H 2 O 2 ) yield (<2.9 %) in acidic electrolyte. Additionally, the dynamic evolution of *OH on the Mn-N x site confirms that Mn-N x can serve as a potential catalytic site for the hydrogen peroxide reduction reaction (HPRR), facilitating H 2 O 2 decomposition. Differential electrochemical mass spectrometry (DEMS) demonstrates that this parallel catalytic pathway effectively weaks the oxidative corrosion of H 2 O 2 on the carbon carrier. The results indicate that the negative half-wave potential shift of CoMnN x C catalysts in acidic electrolyte after 10,000 accelerated durability tests (ADT) is only 11 mV. The synergistic dual-catalytic strategy proposed in this work offers a novel approach for designing high-efficiency and stable transition metal-nitrogen-carbon catalysts.
研究领域:
电化学
·
催化材料
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Jianhui Feng,Hu Zhou,Danyang Chen,Ting Bian,Aihua Yuan
The electrocatalysts with high activity and low cost are essential for hydrogen evolution reaction (HER). Herein, we report an approach to prepare hierarchical core-shell structures Zn x Co 1-x /NC@MoS 2 . The Zn/Co ratio affects the particle sizes of Zn x Co 1-x /NC polyhedra and the distribution of Co nanoparticles , resulting in the change of the amount of exposed active sites and further afforded tunable HER activities. Notably, the hybrids exhibit significantly superior catalytic activities to pristine MoS 2 . The optimal catalyst displays an extraordinary HER performance in acid media with a low overpotential of 130 mV at 10 mA cm −2 and high durability. The remarkable HER properties mainly originate from the fantastic structural characteristics such as abundant exposure of MoS 2 edge-sites, uniform distribution of Co-N x species, as well as the porousness and high conductivity of supports. This research provides a promising strategy to develop inexpensive and highly-efficient HER electrocatalysts derived from metal-organic frameworks and MoS 2 .
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2023
·
IF 4.1
Shuchang Wu,Min Zhao,Zhijun Xia,Junhui Liu,Yiquan Chen,Xiangxing Lv,Zhijian Jia,Zailai Xie
Tetracycline (TC) plays an essential role in both medical treatment and animal husbandry, but its abuse and accumulation in aquatic environments undoubtedly threatens ecosystems and human health. The advanced oxidation processes (AOPs) based on the activation of peroxymonosulfate (PMS) for the degradation of TC and other organic contaminants has attracted increasing attentions. Although metal-organic framework (MOF) derived transition metal‑nitrogen‑carbon material (MNC) shows fascinating potential for PMS activation, the direct carbonization of MOF makes limited active sites available for reaction due to serious agglomeration of the metal species together with the low yield of MNC catalyst. Herein, MOF composite (ZIF-67/NG) is designed via the in-situ growth of ZIF-67 on the N-doped graphene-like carbon (NG). The obtained Co@NC/NG after pyrolysis of ZIF-67/NG enabled the exposure of more active sites without notable aggregation of the Co nanoparticles . Co@NC/NG could effectively degrade TC via the activation of PMS and showed relatively good stability. Meanwhile, it was also highly active in wide pH range and the coexistence of inorganic anions as well as humic acid. Compared to bare ZIF-67 derived Co@NC, Co@NC/NG exhibited higher TOF value. The quenching experiments combined with EPR analysis indicated that both radical and non-radical routes were involved during the TC removal. Superoxide radicals, singlet oxygen and the surface bounded reactive oxygen species were important to the reaction. In comparison, sulfate radicals only made slight contribution and the effect of hydroxyl radicals could be omitted.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
iScience
·
2023
·
IF 5.8
Jian Du,Yunxuan Ding,Yu Guo,Licheng Sun,Fei Li
Carbon-supported iron-cobalt bimetallic electrocatalysts usually exhibit robust catalytic activity toward the oxygen evolution reaction (OER). However, the spatial isolation of Fe species at atomic level on cobalt-carbon solid remains a great challenge for practical catalytic applications in the OER. Here, we report the fabrication of CoFe bimetal porous carbon electrocatalysts by pyrolysis of molecularly defined iron complexes such as FePc (Pc = phthalocyanine) and Fe(acac) 3 pre-encapsulated in the cavities of zeolitic imidazolate framework (ZIF)-67. With this unique strategy, high-loading atomic Fe nanoclusters (Fe-ACs) and Fe single atoms (Fe-SAs) were supported on Co/NC hybrids relying on the size of the molecular Fe precursors. The former exhibited superior OER performance to the single Fe atom-decorated Co/NC, as well as other ZIF-67-derived electrocatalysts. Theoretical modulation suggests Co as the OER active site for Fe-ACs@Co/NC at the in situ -formed FeOOH-ACs/Co 3 O 4 interface, while Fe was proposed as the active site for Fe-SAs@Co/NC.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Qingqing Li,Zhiwei Sun,Yilin Wei,Zixu Ma,Liucheng Wang,Renfeng Nie
Reversible hydrogen storage via Liquid organic hydrogen carriers (LOHCs) is one of the key technologies for efficient utilization of hydrogen energy. How to construct efficient dehydrogenation/hydrogenation catalysts that enable low-temperature catalysis still remains challenging. Herein, we present the design and construction of single-atom Co-N-C(x) catalysts allowing significantly improved acceptorless dehydrogenation of 1,2,3,4-tetrahydroquinoline (THQ). By varying the ligand/Co ratio, the optimal Co-N-C(1.5) can achieve 97.5% dehydrogenated product and 0.82 h −1 TOF value at ambient temperature, overperforming many reported non-noble metal even noble metal catalysts. This catalyst exhibits good recyclability and substrate versatility, enabling ambient temperature dehydrogenation of various N-heterocycles and efficient reverse hydrogenation of aromatic N-heterocycles, thus achieving the loop of reversible hydrogen storage. The active catalyst centers consist of specific Co-N x moieties and nitrogen species within the carbon support. Controlled experiments reveal that the different performance of Co-N-C(x) is determined by density of the Co-N x , and the rate-determining step of THQ dehydrogenation is correlated with the bond cleavages in surface-bound THQ. This work offers a promising pathway for energy-efficient and cost-effective hydrogen energy utilization under practical conditions.
研究领域:
催化化学
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能源材料
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氢能技术
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Gongheng Zhang,Abdullah Ali Mohammed Ahmed Al-Anzah,Fengxiang Yin,Jie Zhang,Guoru Li,Biaohua Chen,Qiuyue Gao,Xian Tong Yu,Yuqian Sun
The precursor ZIF-67/xC-T was prepared by solvothermal and pyrolysis methods. A series of ZIF-67/xC-T-yIL catalysts were then prepared by modifying the surface of the precursor with [BMIM][NTf 2 ] ionic liquid . The results showed that [BMIM][NTf 2 ] as sulfur and nitrogen sources, N, S co-doped carbon can improve the catalytic activity of ORR . Meanwhile, [BMIM][NTf 2 ] formed an oxygen-rich layer on the catalyst surface, which increased the contact between oxygen and the active sites, reduced the alkaline strength of the catalyst surface, and improved the desorption ability of the catalyst to the product. Therefore, the ZIF-67/xC-T-yIL catalyst exhibited better ORR activity in an alkaline electrolyte than the catalyst without [BMIM][NTf 2 ]. Among the ZIF-67/xC-T-yIL catalysts, ZIF-67/1.2 C-600–6IL demonstrated the best ORR catalytic activity, with a half-wave potential of 0.86 V and a limiting current density of 5.21 mA cm −2 in 0.1 mol L −1 KOH, which was comparable to that of commercial 20% wt% Pt/C.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Jingzhu Zhou,Qiong Qu,Wenwen Zhang,Hongyu Wang,Dongsheng Zhang,Guihua Liu
The inherent volume expansion of sulfur, the low conductivity of sulfur species, and the shuttle effects of lithium polysulfides (LiPSs) have limited the commercial deployment of lithium–sulfur (Li–S) batteries. Herein, a tungsten oxynitride skeleton featured with a three-dimensional ordered macroporous (3DOM) structure and embedded with ZIF-67-derived Co-NC nanoparticles (S/Co-NC/WNO) is developed as an effective sulfur host in Li–S batteries. The stable and unique 3DOM structure is conducive to electrolyte permeation and reduces the influence of the volume expansion. Nitrogen doping not only enhances the electrical conductivity of WO3 but also favors LiPS trapping. Meanwhile, Co-NC nanoparticles act as catalytic centers, promoting LiPS adsorption and catalytic conversion, leading to quick and durable Li–S chemistry. Therefore, S/Co-NC/WNO exhibits outstanding electrochemical performance. The initial discharge capacity is 1028.5 mAh g–1 at 0.2 C, and after 100 cycles, a discharge capacity of 938.0 mAh g–1 is maintained. Even under a sulfur loading of 8 mg cm–2, the Li–S battery was capable of reaching an areal capacity of 5.54 mAh cm–2. In addition, the flexible pouch cell based on S/Co-NC/WNO cathode also achieved stable cycling performance, which demonstrates its promising potential in Li–S battery applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2023
·
IF 4.5
Huaiyu Li,Chenxi Xu,Wei Wang,Gangyong Li,Junlin Huang,Liang Chen,Zhaohui Hou
The development of single atom catalysts is considered as a hotspot in the field of electrocatalysis. As the representative of single atom catalysts, metal and nitrogen co–doped carbon (M N C) attracts worldwide attentions due to its great potential in the application of oxygen reduction reaction (ORR). However, the actual preparation of M N C still confronts with tedious procedure, harsh condition and relatively low loading of single metal atom. In this work, we successfully prepare high–loading 3D Co N C architecture by a facile oxidation polymerization followed by pyrolysis process employing 3D nitrogen–doped graphene hydrogel (NGH) and pyrrole (PY) as the reaction precursors. Benefitting from the individual advantages of 3D NGH and PY, the resultant 3D Co N C possesses unique 3D architecture, high–loading single Co atom (2.74 wt%), large specific surface area and enriched mesopores, which benefit the exposure of sufficient catalytic sites and facilitate electrons transfer and ions transport, thus generating much enhanced ORR performance. When used as the cathode catalyst for zinc–air batteries (ZABs), it shows comparable performance with commercial Pt/C catalyst. Clearly, our finding offers a good guidance on the design and synthesis of advanced high–loading single atom catalysts.
研究领域:
材料科学
·
电催化
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2022
·
IF 5.477
Qi Chen,Xiaogang Su,Xing Liu,Jichao Wang,Rongguo Song,Daping He,Somboon Chaemchuen,Francis Verpoort
Background A bimetal (Fe/Ni) doped cobalt-nitrogen-carbon matrix (Fe/Ni-CoNC) with hierarchical architecture originating from zeolitic imidazolate framework (ZIF-67) is purposely designed. Methods The metals within the Co-N-C matrix are well distributed. Besides, Fe/Ni-CoNC was supported on reduced graphene oxide (RGO). We demonstrate that the three-element combination can synergistically contribute to different advantages for microwave absorption. Therefore, the combination of Fe and Ni synergized the absorber to obtain a good impedance match for the best microwave absorption. Significant Findings The synthesized Fe/Ni-CoNC/RGO with optimized element components exhibited an excellent wave absorption of -51.6 dB at 7.2 GHz obtained with a thin thickness of 2.5 mm. When combining Fe/Ni-CoNC/RGO with a thermoset resin, namely polydicyclopentadiene (PDCPD), the final product reached a maximum absorption of -24.5 dB with a thickness of 1.5 mm. This compounding confirmed that interfacial polarization, defect polarization, and natural resonance are synchronously enhanced for improved absorption performance.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2024
·Vol. 16
·期 10
·5215-5221
·
IF 5.8
Yangdong Zhou,Junda Chen,Zhiyin Huang,Yuqin Peng,Lixin Xing,Chunmei Tang,Ning Wang,Ling Meng,Mingjie Wu,Lei Du,Siyu Ye
The cathodic oxygen reduction reaction (ORR) has been continuously attracting worldwide interest due to the increasing popularity of proton exchange membrane (PEM) fuel cells. So far, various Pt-group metal (PGM) or PGM-free catalysts have been developed to facilitate the ORR. However, there is still a gap to achieve the expected goals as proposed by the U.S. Department of Energy (DoE). Recently, PGM-free@PGM hybrid catalysts, such as the M/N/C@PtM catalyst, have achieved the milestones of oxygen reduction, as reviewed in our recent work. It is, nevertheless, still challenging to unravel the underlying structure–property relationships. Here, by applying different Pt/Co ratios, a series of Co/N/C@PtxCo catalysts are synthesized. Interestingly, the ORR activity and stability are not linear with the Pt content, but show a volcano-like curve with increased Pt usage. This relationship has been deeply unraveled to be closely related to the contents of pyrrolic N, pyridinic N, and graphitized carbon in catalysts. This work provides guidelines to rationally design the coupled PGM-free@PGM catalysts toward the ORR by appropriate surface engineering.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Energy
·
2018
·
IF 13.12
Qirui Liang,Huihui Jin,Zhe Wang,Yuli Xiong,Shuai Yuan,Xianci Zeng,Daping He,Shichun Mu
Developing low-cost, highly active, and stable bifunctional electrocatalysts is a challenging issue in electrochemical water electrolysis . Herein, we develop a simple metal organic frameworks (MOFs) based approach to prepare bifunctional Co-NC@ Mo 2 C complex catalysts. Differently from traditional carbon encapsulated functional nanomaterials , herein the carbon-based framework derived carbonitride and Co nanoparticles (Co-NC) are encapsulated with Mo 2 C. Benefiting from the unique reverse-encapsulation structure and synergetic effects of Mo 2 C and Co-NC, the Co-NC@Mo 2 C catalyst shows superior hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance. In alkaline media , it affords the current density of 10 mA cm −2 at low overpotentials of 99 mV and 347 mV for HER and OER, respectively. Interestingly, due to a reversed encapsulation structure where Co nanoparticles are protected by Mo 2 C, it leads to an outstanding HER catalytic activity (a low overpotential of 143 mV) and stability in acidic solutions. Remarkably, when employed as both the cathode and anode for overall water splitting, a low cell voltage of 1.685 V is required to reach the current density of 10 mA cm −2 in alkaline media with excellent stability, making the Co-NC@Mo 2 C an efficient non noble metal bifunctional electrocatalyst toward water splitting.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）