CHEMISTRY-A EUROPEAN JOURNAL
·
2017
·Vol. 23
·期 58
·14597-14603
·
IF 5.317
Xinghua Chen,Fei He,Yanfei Shen,Yiran Yang,Hao Mei,Songqin Liu,Toshiyuki Mori,Yuanjian Zhang
Graphical Interface effect : A study into the intrinsic role of carbon supports for Fe-N/C alternatives to Pt/C catalysts for oxygen reduction in fuel cells revealed that when immobilized on suitable support, the Fe−N/C demonstrated an improved mass J K that was comparable to that of Pt/C and higher than most reported M−N/C catalysts (see scheme). The mass kinetic current density (mass J K ) of most extensively reported M−N/C catalysts (M represents non-precious metal elements such as Fe, Co, and Cu), a potential alternative to noble metal catalysts in fuel cells, is poorer than that of commercial Pt/C. Thus, deep understanding of the intrinsic roles of carbon supports may contribute to the development of M−N/C catalysts from a practical point of view. Herein, the routinely used carbon supports, i.e. carbon black (CB) and carbon nanotubes (CNT) that have different morphology and crystallinity, were investigated to uncover the factors that affected the mass J K of Fe−N/C in electrocatalytic oxygen reduction. When immobilized on CB, the ionic liquids-derived Fe−N/C exhibited an enhanced mass J K (4.45 A g −1 at 0.80 V vs. RHE) by a factor of 2.14 times, comparable to that of Pt/C (5.79 A g −1 ) and higher than most reported M−N/C catalysts to our best knowledge. In contrast, the CNT support system showed no improvement. It was revealed that a compatible interface between the Fe−N/C precursors and the carbon supports was vital to ensure in-situ growth of a uniform catalyst layer on the supports during pyrolysis. This subsequently promotes the mass J K by exposing more embedded active sites and introducing favorable slit pores for effective mass-diffusion. This work would be promising to address the long-term overlooked challenge of the low mass J K of M−N/C catalysts in replacing noble-metal catalysts for practical fuel cell applications.
✓ 已验证
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Enkang Fu,Yu Qiu,Huaichang Lu,Sijun Wang,Lishan Liu,Hanjun Feng,Yanxin Yang,Zizhan Wu,Yunlong Xie,Feng Gong,Rui Xiao
Ammonia (NH 3 ) has been regarded as an attractive energy source for hydrogen production via catalytic decomposition , especially over non-noble metal catalysts . Owing to the decent performance and low cost, nickel (Ni) based catalysts have been widely studied for catalytic decomposition of NH 3 where the decomposition rates, can be further tailored by adding other metals. Herein, we synthesized bimetallic M(M = Co, Fe, Cu)Ni/Al 2 O 3 catalysts delivering superior catalytic performance at a wide temperature range of 350–750 °C. Co-Ni/Al 2 O 3 demonstrated nearly 100% conversion of NH 3 decomposition to H 2 at 700 °C and the gas hourly space velocity of 30,000 ml g −1 min −1 , which was ~20.85% higher than that of intrinsic Ni/Al 2 O 3 . The structural characterizations indicated that Co could decrease the particle size and enhance the dispersion of active sites. The density functional theory calculations substantiated that the associative decomposition of N to generate N 2 was the rate-determining step of the NH 3 decomposition reactions . NH 3 Temperature Programmed Desorption (TPD) results suggested that the enhanced catalytic performance was predominantly attributed to the Co that decreases the energy barrier for the associative decomposition of N to form N 2 . This study provides new insights in designing diverse catalysts for efficient NH 3 decomposition for controllable H 2 production.
✓ 已验证
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2008
·
IF 2.394
Yunlai Ren,Zhifei Liu,Shuang Zhao,Xinzhe Tian,Jianji Wang,Weiping Yin,Shebin He
Commercially available and inexpensive ethylenediamine/Cu(OAc) 2 · H 2 O has been found to be a highly effective catalyst system for the cyanation of aryl bromides in the solvent of NMP. At the same time, the highly activated aryl chlorides with NO 2 groups gave corresponding benzonitriles in good yields. Similar to the previous observation, it is not necessary to use an excess of K 4 [Fe(CN) 6 ] in the cyanation reaction (only 20 mol% of K 4 [Fe(CN) 6 ] was used). In other hand, a more remarkable KI-accelerated effect was observed for the cyanation reaction: the addition of KI increased the yield from 6% to 91% in the cyanation of bromobenzene.
✓ 已验证
DOI
高影响因子
Carbon Resources Conversion
·
2020
·
IF 0
Yuming Li,Qiyang Zhang,Xue Yu,Guiling Jiang,Yajun Wang,Guiyuan Jiang,Zhen Zhao,Chunming Xu
Nitrogen doped carbon species (NC) was introduced into Fe based catalyst and applied into propane non-oxidative dehydrogenation. With characterizations of XRD, TEM and XPS, it was deduced that the NC modification induces the electrons transferred from NC species to Fe species, leading to electron-rich Fe species. Consequently, propane conversion and propene selectivity were increased by suppressing the by-products formation. It was also confirmed that such a modification strategy could be also extended to ones with different supports, iron precursors, and NC precursors.
✓ 已验证
DOI
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2019
·
IF 5.04
Zhewen Ma,Jianxin Zou,Darvaish Khan,Wen Zhu,Chuanzhu Hu,Xiaoqin Zeng,Wenjiang Ding
Two kinds of metal-organic frameworks (MOFs) based on Co (II) and Fe (II) as metal ions and trimasic acid (TMA) as organic linker were synthesized. They were used to prepare corresponding MgH 2 -TM MOF (TM = Co, Fe) composites via ball-milling. X-ray diffraction analyses show the formation of Mg 2 Co and α-Fe phases in MgH 2 -TM MOF composites after decomposition. Both of the well dispersed Mg 2 Co and α-Fe nanoparticles exhibit considerable catalytic efficiency in accelerating the sorption kinetics of MgH 2 . The dehydrogenated MgH 2 -Fe MOF composite shows faster hydriding kinetics than the pure MgH 2 and MgH 2 -Co MOF. Meanwhile, the apparent dehydrogenation activation energy ( E d ) of the MgH 2 -Co MOF and MgH 2 -Fe MOF composites are 151.3 ± 9.4 and 142.3 ± 6.5 kJ/mol H 2 , both of which are lower than that of pure MgH 2 (181.4 ± 9.2 kJ/mol H 2 ). The improvement on the sorption kinetics of the MgH 2 -TM MOF powders is mainly attributed to the catalytic effects of nano-sized Mg 2 Co and α-Fe formed on the surface of Mg/MgH 2 particles.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Jie Wang,Yumei Chen,Shuyan Guan,Jianchao Shi,Mingbin Li,Baozhong Liu
Hydrolytic dehydrogenation of ammonia borane (AB) has attracted much attention due to its high hydrogen content and stability. Therefore, the design and construction of low-cost and high-performance catalysts for AB hydrolysis are of great significance. In this work, Co/CoFeO x -X (X is the additional content of Fe precursor) bimetallic oxide nanofilms having an amorphous structure were prepared on an (IL)/water interface for the hydrolysis of AB. Strategies including the rapid addition of metal precursors and variation of Co/Fe atom ratios were employed to induce an amorphous structure for inhibiting the rearrangement of the formed metal nuclei and optimizing the alloying effect on the IL/water interface. This ultrathin amorphous nanofilm structure can expose more metal active sites. Moreover, the electronic interaction between Fe and Co after doping Fe into the Co/CoO x nanofilms facilitates the adsorption and activation for AB and H 2 O molecules. As a result, the optimized Co/CoFeO x -25 catalyst exhibits excellent catalytic activity with a turnover frequency (TOF) value of 12.25 mol H2 ·mol Co –1 ·min –1 , which is considerably higher than that of the monometallic Co/CoO x catalyst. This enhanced activity can be ascribed to the morphology advantages and the electronic effect of Fe and Co on the Co/CoFeO x -25 catalyst. This work provides a promising method to design the highly efficient non-noble metal catalysts for the hydrolysis of chemical hydrides.
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 56
·84166-84179
·
IF 5.19
Gao Panting,Li Yuran,Lin Yuting,Chang Liping,Zhu Tingyu
Catalytic hydrolysis of carbonyl sulfur (COS) from blast furnace gas is one of the keys to achieving ultra-low emission in the iron–steel industry. To improve the COS hydrolysis activity on γ-Al 2 O 3 catalyst at low temperature, catalysts with Fe or La as the active component were prepared by the impregnation method, the physical and chemical properties of the catalyst were characterized by ICP, XRF, XRD, BET, and TPD. The hydrolysis activity of COS and sulfur resistance ability on various catalysts were investigated in a fixed bed reactor combined with gas chromatography. The results show that the addition of Fe or La improves the COS hydrolysis activity due to the increase in alkaline sites on the catalyst surface. The roles of various alkaline sites on catalysts have been recognized. The weak alkaline center is the reaction site of COS hydrolysis, the middle and strong alkaline centers are the adsorption and oxidation sites of H 2 S. The Fe/Al 2 O 3 catalyst has higher hydrolytic activity and oxidative capacity for H 2 S removal due to forming more sulfate species on Fe. The La/Al 2 O 3 catalyst has higher hydrolysis efficiency in that H 2 S rapidly desorbs from the catalyst surface to the gas phase, and then, the activity of reaction sites is recovered. This provides an idea for the preparation of sulfur-resistant catalysts.
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Zhihao Shen,Shuming Wen,Yongchao Miao,Han Wang,Qicheng Feng
Unavoidable metal ions commonly exist in the pulp during flotation. These ions can affect the floatability of minerals, and they can also result in the differences in the surface features between different minerals. In this study, how Fe 3+ affected the flotation behavior of cerussite was investigated by micro-flotation tests. The corresponding adsorption characteristics of the sulfidizing agent and collector on the surfaces of cerussite were investigated by surface-analysis techniques. The results of micro-flotation tests showed that the floatability of cerussite significantly decreased when Fe 3+ was added before Na 2 S and xanthate. The flotation recovery of cerussite decreased compared with that obtained without participation of Fe 3+ . Additionally, the results of xanthate and Na 2 S adsorption tests, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and zeta potential measurements verified that Fe 3+ and its hydrophilic hydroxyl derivatives (Fe-OH compounds) resulted in reduced amounts and reactive activities of S-bearing species adsorbed on the surfaces of cerussite. This decreased the adsorption capacity of subsequently added xanthate, resulting in the difficulty in effectively recovering cerussite in the sulfidization-xanthate system.
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Cederick Cyril Amoo,Mingquan Li,Aqsa Noreen,Yajie Fu,Elton Maturura,Ce Du,Ruiqin Yang,Xinhua Gao,Chuang Xing,Noritatsu Tsubaki
Keen interest is taken in zeolite-encapsulated metal nanoparticles (NPs) owing to their excellent performance and ultrastability in heterogeneous catalysis. Herein, we propose a simple and efficient method to contain Fe NPs within zeolite Y microcrystals. First, a low-pressure technique was developed to successfully synthesize the zeolite Y microcrystals. The technique was then invoked, using Fe NPs fixed in nanosized C spheres as a precursor, to prepare zeolite Y-embedded Fe composite catalysts. The C spheres served as a template that restricted Fe NP growth within zeolite Y. Above all, the successful confinement of small Fe NPs within the microcrystals of zeolite Y enhanced the catalyst activity with 36.2% selectivity for light olefins (C2–C4=) at a CO conversion of 91.2% during evaluation in Fischer–Tropsch synthesis. The techniques presented in this work open up a new avenue worth exploiting for the synthesis of nano/microcrystalline materials and highly active metal–zeolite composites in heterogeneous catalysis.
✓ 已验证
DOI
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Liwei Chen,Xu Zuo,Liang Zhou,Yang Huang,Shengjiong Yang,Tianming Cai,Dahu Ding
The contamination issue caused by the antibiotics is now a big challenge due to its great potential hazardous to the human beings. Herein, three Co/Fe bimetallic oxides were synthesized for the activation of peroxymonosulfate (PMS) to degrade norfloxacin. The elemental analysis results confirmed the stoichiometric ratio of Fe/Co was 1.02, 2.03, and 6.65 (CoFe 2 O 4 ·CoO x , CoFe 2 O 4 , Co 0.4 Fe 2.6 O 4 ), respectively. The normalized pseudo-first-order kinetic rate constant ( k app ) of Co 0.4 Fe 2.6 O 4 was 0.18 L/(m 2 ·min), which was over 10 times higher than those of CoFe 2 O 4 ·CoO x (0.010 L/(m 2 ·min)) and CoFe 2 O 4 (0.012 L/(m 2 ·min)). The degradation process would be further accelerated under weak basic condition (pH = 8.5). The enhanced surface hydroxyl groups were found to be the probable reason for the higher efficiency through the XPS analysis. Moreover, the sulfate radical rather than hydroxyl radical dominated the degradation process in the developed Co 0.4 Fe 2.6 O 4 /PMS system. Overall, the magnetic Co/Fe bimetallic oxide catalyst prepared in this study could be served as a high-quality candidate for the catalytic oxidation of refractory organic pollutants.
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 31
·14756-14771
·
IF 4.682
Cai Menglu,Wang Xiaozhong,Cao Wenhui,Chen Yingqi,Dai Liyan
A fine-tuned mordenite was prepared to overcome the low selectivity of tert-amyl anthracene production in the direct alkylation of anthracene. Herein, a series of boric acid-modified Fe-Zr mordenite materials were prepared, and tert-amyl anthracene was smoothly and efficiently obtained over these catalysts. The boron sites in modified catalyst promoted the alcohol dehydrogenation, which benefited the reaction conversion. Moreover, the existence of Brønsted and Lewis acid sites was the key in alkylation reaction, making 1.0B-Fe-Zr/MOR good reactivity (Conv. 47.8%, Sel. 91.4%). Calculated results correlated the products properties with catalyst structures, verifying that boric acid-modified Fe-Zr/MOR was a successful shape-selective catalyst. The present work opens a new frontier for a sustainable and high-selective method to process anthracene alkylation. Graphical abstract
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Chen Wen,Ligang Chen,Yating Xie,Jingying Bai,Xin Liang
In order to explore the effect of Fe doped CoP nanosheets on both hydrogen evolution reaction (HER) and hydrodesulfurization (HDS), FeCoP/C nanosheets have been successfully synthesized by the solvothermal process with Fe doped ZIF-67/C for the growth of FeCo-hydroxides nanosheets , as well as a following low-temperature phosphorization process. The performance evaluation results show that the FeCoP/C nanosheet exhibits an excellent acidic HER performance and an ordinary HDS performance compared to CoP/C and FeP/C catalysts. Experimental characterization and density functional theory results show that the high HER activity of the FeCoP/C nanosheet can be attributed to the fact that the nanosheet structure facilitates the exposure of active sites and the doped Fe atoms make CoP have a suitable hydrogen adsorption energy , while the ordinary HDS activity of the FeCoP/C nanosheet can be attributed to the fact that the doped Fe atoms can inhibit the cleavage of C–S bonds by CoP.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）