Advanced Energy Materials
·
2022
·Vol. 12
·期 32
·2201600
·
IF 29.698
Zhenyu Chen,Chao Hao,Bowen Yan,Qiuyan Chen,Huiyan Feng,Xiaoqing Mao,Jianmei Cen,Zhi Qun Tian,Panagiotis Tsiakaras,Pei Kang Shen
Traditional calcination usually causes sintering of Pt, which diminishes Pt exposure in proton exchange membrane fuel cell (PEMFC) electrodes. In the present work, a facile self-confined method for synthesizing highly dispersed PtCo-alloy on Co, N co-doped mesoporous carbon (PCN-MC) is developed via a dual-template strategy. Owing to the co-confined effect of Zn in the bimetallic zeolite-based imidazolate framework (ZIF) and Mg(OH) 2 template, ultra-fine 2.7 nm PtCo-alloy with 2–3 atomic-layer Pt-skin nanoparticles are obtained. By adjusting the Co/Zn feeding-ratio in the bimetallic ZIF at 8/7, the alloying degree and nanoparticle size are optimized to achieve an outstanding oxygen reduction reaction activity with a high mass activity (MA) of 0.956 A mg Pt −1 in 0.1 m HClO 4 , about 7.5-fold of that of commercial Pt/C. Furthermore, notable durability is also achieved with 81% retention of the initial MA after 30k cycles conducted between 0.6–1.0 V (versus reversible hydrogen electrode). These features are also verified by a H 2 –Air fuel cell test with an excellent combination of mass activity, power density, and durability. This strategy provides a feasible route for the large-scale synthesis of highly-dispersed PtCo-alloy catalysts.
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
·
2021
·Vol. 16
·期 19
·2952-2957
·
IF 4.568
Fengwei Zhang,Mengmeng Liu,Qiang Liu,Jingjing Li,Boyang Li,Zhengping Dong
Graphical A facile and in-situ methanol-mediated strategy was proposed to fabricate Pd@ZIF-8 catalyst for efficient and size-selectivity alkenes hydrogenation. In-situ encapsulation of tiny and well-dispersed Pd nanoparticles (Pd NPs) in zeolitic imidazolate frameworks (ZIFs) was firstly achieved using a one-pot and facile methanol-mediated growth approach, in which methanol served as both solvent and a mild reductant. The microstructure, morphology, crystallinity, porosity as well as evolution process of the catalysts were determined by TEM, XRD, N 2 adsorption and UV-vis spectra. Due to the complete encapsulation of such Pd NPs combined with ultrahigh surface area and uniform microporous structure of ZIF-8, the resulting Pd@ZIF-8-60 min nanocomposite exhibited more superior catalytic activity for olefins hydrogenation with TOF of 7436 h −1 and excellent size selectivity than previously reported catalysts. Furthermore, the catalyst displays excellent recyclability for 1-octene hydrogenation and without any loss of the Pd active species.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2021
·Vol. 11
·期 5
·533
·
IF 4.146
Jing Chen,Yingchun Guo,Tengteng Kang,Xingchi Liu,Xiaomei Wang,Xu Zhang
It is wise to mimic a bioinspired system to design a nanoreactor as a catalyst containing multiple components for a cascade reaction. Here, we report the uniform growth of well-dispersed nano-scale ZIF-8 crystals on the pore walls of 3DOM TiO2via the TEA-assisted crystallization process. The UV-vis spectra indicate that the ZIF-8 photosensitizer can extend the visible-light absorption of 3DOM TiO2. The obtained nanoreactor can efficiently catalyze the one-pot aromatic alcohol oxidization and Knoevenagel condensation cascade reaction for larger molecules. This work offers an important strategy for preparing semiconductor–MOF multifunctional composites with a spatially separated compartmentation for the cascade reaction.Keywords:crystal growth;cascade reaction;nanoreactor;semiconductor–MOF composite
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Ahmed M. Omer,Eman M. Abd El-Monaem,Mona M. Abd El-Latif,Gehan M. El-Subruiti,Abdelazeem S. Eltaweil
Metal organic frameworks (MOFs) have become premium candidates for the removal of hazardous contaminants from wastewater. However, MOFs have a vast obstacle which is their poor recyclability. In this study, ZIF-67 was decorated with magnetic Fe 3 O 4 nanoparticles, and then embedded into aminated chitosan (AmCs) matrix to form core-dual shell Fe 3 O 4 /ZIF-67@AmCs composite beads. Diverse analysis tools were utilized to ensure the successful fabrication of the magnetic composite beads. The fabricated magnetic composite beads were examined their adsorptive removal aptitude towards toxic Cr(VI) ions. The gained results refereed that a maximum adsorption capacity of 119.05 mg/g was attained by magnetic Fe 3 O 4 /ZIF-67@AmCs composite beads at 25 °C. The process obeyed both of Langmuir and Freundlich isotherm models, and the pseudo 2nd order was more suitable kinetic model to represent the adsorption process. Besides, Fe 3 O 4 /ZIF-67@AmCs composite showed an excellent recyclability for the removal of Cr(VI) ions from their aqueous solutions for seven consecutive cycles.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 12
·1-8
·
IF 6.232
Ding Wen,Ma Mingxuan,Du Yingxiang,Chen Cheng,Ma Xiaofei
An in situ zeolite imidazole metal organic framework-90 (ZIF-90) modified capillary was prepared via the method of solvothermal synthesis. The coating of ZIF-90 was characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry, and EOF. Capillary electrochromatography–based enantioseparation of the basic drugs propranolol (PRO), metoprolol (MET), atenolol (ATE), bisoprolol (BIS), and sotalol (SOT) was performed using lactobionic acid (LA) as the chiral selector. Compared with an uncoated silica capillary, the resolutions are greatly improved (PRO 1.40 → 3.23; MET 1.07 → 3.19; ATE 1.07 → 3.15; BIS 1.16 → 3.41; SOT 1.00 → 2.79). Effects of buffer pH values, proportion of organic additives, concentration of lactobionic acid, and applied voltage were investigated.
Schematic presentation of the preparation of zeolitic imidazolate framework-90 (ZIF-90) modified capillary (ZIF-90@capillary) for enantioseparation of drug enantiomers. The capillary was applied to construct capillary electrochromatography system with lactobionic acid for enantioseparation of basic chiral drugs.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Jia Wen,Xiaohong Hu
Recently, the developments of MOFs and their applications on heavy metal removal have attracted much attention. In this paper, we focused on the influence of co-existing ions on the adsorbability of epigallocatechin gallate (EGCG) modified ZIF-8 in a multi-metal system (Cd(II), Cu(II), Ni(II), and Cr(VI)). It was found that the adsorption of Cd(II), Cu(II), Ni(II), and Cr(VI) on the ZIF-8-EGCG fitted well with the pseudo second-order kinetic model and Langmuir isotherm. The adsorption selectivity of ZIF-8-EGCG in the mixed metal solution followed the order of Cu(II) ≫ Cr(VI) > Cd(II) > Ni(II). Besides, Cu(II) was the most attractive substance with a maximum capacity of 232.97 mg·g −1 . Copper also disturbed the adsorption of Cd(II) and Ni(II) and contributed the most to the Cr(VI) removal. The natural anions (e.g., Cl − , NO 3 – , AsO 2 − , SO 4 2− ) significantly impeded Cr(VI) adsorption, while low concentrations of natural cations (e.g., K + , Na + , Ca 2+ , and Mg 2+ ) facilitated the adsorption of Cd(II), Cu(II) and Ni(II).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 64
·38906-38911
·
IF 3.119
Changshui Wang,Jiahui Zhang,Zenong Zhang,Guancheng Ren,Dandan Cai
Controllable structure and defect design are considered as efficient strategies to boost the electrochemical activity and stability of catalysts for the oxygen evolution reaction (OER). Herein, oxygen defect hollow Co3O4/nitrogen-doped carbon (OV-HCo3O4@NC) composites were successfully synthesized using tannic acid-modified ZIF-67 (TAMZIF-67) as the precursor through a one-step pyrolysis. Tannic acid provides abundant oxygen during the pyrolysis process of the modified ZIF-67, which can contribute to the formation of oxygen defects and the construction of a hollow structure. The existence of oxygen defects is shown by X-ray photoelectron spectroscopy and electron paramagnetic resonance, whereas the hollow structure is confirmed by transmission electron microscopy. The optimized OV-HCo3O4@NC shows good electrocatalytic activity and exhibits a low overpotential of 360 mV at a current density of 10 mA cm−2 in 0.1 M KOH due to the hollow structure, abundant oxygen defects, and good electrical conductivity. This work provides valuable insights into the exploration of promising OER electrocatalysts with oxygen defects and special structures.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Jingjing He,Yu Wan,Wenjun Zhou
Developing high-efficient hybrids carbon catalysts for PMS-based advanced oxidation process (AOPs) are crucial in the field of environmental remediation. In this work, novel carbon nanocubes (xFe‒N‒C) with three-dimensional porous structure and abundant well-dispersed FeN x sites were obtained via a skillful cage-encapsulated-precursor pyrolysis strategy. The as-synthesized xFe‒N‒C exhibited superb activity for phenol degradation by activating peroxymonosulfate (PMS). Besides, the catalytic system not only possessed good recycling performance, wide pH adaptation and relatively low activation energy, but also had high resistance to environmental interference. Singlet oxygen ( 1 O 2 ) dominated non-radical process was responsible for phenol degradation rather than traditional radical pathways. Impressively, the doping level of Fe could regulate FeN x contents in catalysts, and the catalytic activity of xFe‒N‒C was greatly enhanced with increasing FeN x contents. Based on density functional theory calculations (DFT), the introduction of FeN x sites regulated the electronic structure of catalysts. Such electron-deficient Fe center acted as electron acceptor to receive electrons transmitted by the adsorbed PMS , thus generating highly reactive 1 O 2 for rapid phenol oxidation. This work provides a new insight into the innovation in transition metal-nitrogen hybrid carbon catalysts and highlights the pivotal roles of FeN x sites in 1 O 2 generation during PMS activation process.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 26
·14259-14266
·
IF 6.895
Yi Guan,Nan Li,Yongliang Li,Lingna Sun,Yuan Gao,Qianling Zhang,Chuanxin He,Jianhong Liu,Xiangzhong Ren
Bottom-up construction of transition copper–nitrogen–carbon (Cu–N–C) electrocatalysts with high-performance and long-term durability for the oxygen reduction reaction (ORR) still remains a great challenge. Herein, we propose a temperature-controlled synthesis strategy with confinement effect for fabrication of a novel two-dimensional dual-metal (Cu/Zn) zeolitic imidazolate framework material, which presents an ultrathin nanosheet morphology after high-temperature thermal treatment (denoted as Cu–N-UNS). By controlling the reaction temperature as well as regulating the ratio of metal ions and taking advantages of the confinement effect of surfactants, the rationally designed ultra-thin carbon layer not only prevents aggregation of transition Cu particles and avoids direct contact with reactants and electrolyte solutions to enhance the durability of electrocatalysts, but also shortens the electronic transmission path between the active transition metal species and carbon surface. Therefore, the electrocatalyst exhibits excellent electrocatalytic performance for the ORR (E1/2 ≈ 0.898 V), which is superior to those of state-of-the-art benchmark noble-metal electrocatalysts. Moreover, the even distribution of Cu–N–C and existence of N–Cu2+–Cu0 active sites make a great contribution to the electrocatalyst activity. Notably, the Cu–N-UNS used as air electrodes for Zn–air batteries also exhibits a high peak power density of ≈134.7 mW cm−2 at a current density of ≈231.9 mA cm−2 with remarkable durability.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Hui Ouyang,Jiaxin Xian,Jiaqi Gao,Lvxia Zhang,Wenwen Wang,Zhifeng Fu
Superior to traditional nanoscale catalysts, single-atom site catalysts (SASCs) show such merits as maximal catalysis efficiency and outstanding catalytic activity for the construction of analytical methodological platforms. Hereby, an in situ etching strategy was designed to prepare yolk-shell Co SASCs derived from ZIF-8@SiO2 nanoparticles. On the basis of direct chemical interactions between precursors and supports, the Co element with isolated atomic dispersion was anchored on ZIF-8@SiO2 nanoparticles. The Co SASCs possess high Fenton-like activity and thus can catalyze the decomposition of H2O2 to produce massive superoxide radical anions instead of singlet oxygen and hydroxyl radicals. With the activity for producing superoxide radical anion, Co SASCs can greatly improve the chemiluminescent (CL) response of a luminol system by 3133.7 times. Furthermore, the SASCs with active sites of Co–O5 moieties were utilized as the CL probes for establishment of an immunoassay method for sensitive detection of mycotoxins by adopting aflatoxin B1 as a mode analyte. The quantitation range is 10–1000 pg/mL, and the limit of detection is 0.44 pg/mL (3σ) for aflatoxin B1. The proof-of-principle work elucidates the practicability of direct chemical interactions between precursors and supports for forming SASCs with ultrahigh CL response, which can be extended to the exploitation of more sorts of SASCs for tracing biological binding events.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION SCIENCE
·
2023
·
IF 8.3
Kai Wei,Yuankun Wei,You Zhang,Valeryia Kasneryk,Maria Serdechnova,Hao Wang,Zhe Zhang,Yujie Yuan,Carsten Blawert,Mikhail L. Zheludkevich,Fei Chen
A strategy based on in situ host-guest nanoconfinement was used to assist the synthesis of a ZIF-8 host loaded with a corrosion inhibitor 8-hydroxyquinoline (8-HQ) guest by a facile one-step process at room temperature. Results showed that a Zn-(bis-8-hydroxyquinoline) guest encapsulated ZIF-8 host composite (Q@ZIF-8) was formed. The Q@ZIF-8 proves to have an inhibition efficiency of over 91% to protect the aluminum alloy substrate against corrosion in the corrosive solution after 2 days. Additionally, the pH-responsive Q@ZIF-8 can release 8-HQ species in form of hydroxyquinoline zinc complex and improves the corrosion resistance of the epoxy coating.
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 45
·e202303025
·
IF 2.1
Sida Hu,Xiuqin Dong,Jianhang Tian,Lingtao Wang,Yifei Chen,Haoxi Jiang
Graphical We prepared the Co-based materials via the pyrolysis of ZIF-67 at low temperature, and obtained the optimum catalyst ZIF-67-Sg-350-10 with the conversion of 1-butene, aldehyde selectivity and n/i ratio of 94.9 %, 77.1 % and 2.2, respectively. We prepared the Co-based materials via the pyrolysis of ZIF-67 at low temperature (250 °C~350 °C), and obtained the optimum catalyst ZIF-67-Sg-350-10 with the conversion of 1-butene, aldehyde selectivity and n/i ratio of 94.9 %, 77.1 % and 2.2, respectively. The conversion of 1-butene and aldehyde selectivity obviously increased with the increasing pyrolysis temperature and pyrolysis time. It was found that the interaction between the Co cluster and N-doped carbon composites could improve the hydroformylation activity. Different catalyst models were built to investigate the active centers (Co) in the derived materials. The Co-N4 surface was the best catalyst model with the lowest hydrogen insertion reaction energy barrier (0.37 eV).
✓ 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）