JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Rui-Min Sun,You-Qiang Yao,Ai-Jun Wang,Ke-Ming Fang,Lu Zhang,Jiu-Ju Feng
Replacing precious metal catalysts with low-price and abundant catalysts is one of urgent goals for green and sustainable energy development. It is imperative yet challenging to search low-cost, high-efficiency, and long-durability electrocatalysts for oxygen reduction reaction (ORR) in energy conversion devices. Herein, three-dimensional low-cost Co 3 Fe 7 nanoparticles/nitrogen, manganese-codoped porous carbon (Co 3 Fe 7 /N, Mn-PC) was synthesized with the mixture of dicyandiamide, cobalt (II) tetramethoxyphenylporphyrin (Co(II)TMOPP), hemin , and manganese acetate by one-step pyrolysis and then acid etching. The resultant Co 3 Fe 7 /N, Mn-PC exhibited excellent durability and prominent ORR activity with more positive onset potential ( E onset , 0.98 V) and half-wave potential ( E 1/2 , 0.87 V) in 0.1 M KOH electrolyte, coupled with strong methanol resistance. The pyrolysis temperature and optimal balance of graphite with pyridine-nitrogen are of significance for the ORR performance. The prepared Co 3 Fe 7 /N, Mn-PC displayed excellent ORR performance over commercial Pt/C in the identical environment. It was ascribed to the uniform 3D architecture, Mn- and N-doping effects by finely adjusting the electronic structures, coupled with the synergistic catalytic effects of multi-compositions and multi-active sites. This work provides some constructive guidelines for preparation of low-cost and high-efficiency ORR electrocatalysts.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Lidong Kou,Jing Wang,Liang Zhao,Kai Jiang,Xinxin Xu
Conversion of waste sludge into biochar-based catalysts has been considered as a feasible alternative for sludge treatment, and dewatering of waste sludge is a key process for further treatment and disposal. In this study, KMnO 4 was used as both a chemical conditioner to assist Fe-rich sludge dewatering and a chemical modifier to incorporate Mn oxides into the biochar catalysts. Results showed that the sludge dewatering was substantially improved when KMnO 4 dosage was above 13% DS (dry sludge), and more than 99% of Mn was retained in the sludge cake. After pyrolysis of the sludge cake, a series of Mn,Fe-codoped biochar catalysts (assigned to x -Mn-FeBC) were obtained. The catalysts could activate peroxymonosulfate (PMS) well for complete removal of phenolic contaminants including phenol, bisphenol A (BPA) and 2,4-dichlorophenol (DCP) over a wide pH range (2.5–12) with the co-existence of water constituents. After 5 consecutive cycles, the catalytic performance of 13%-Mn-FeBC was decreased by half, but it could be fully recovered by simple calcination at 600 o C. It was proposed that radical and non-radical oxidation processes worked together for organic degradation, but non-radical pathways involving 1 O 2 oxidation and electron transfer between PMS and organic played more crucial roles. This study proposed a novel sludge treatment process by combining enhanced sludge dewatering with efficient catalyst preparation, and the as-prepared catalysts were promising in PMS activation and organic degradation.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Xiaodong Yang,Zhenghang Liu,Yinshan Jiang,Fangfei Li,Bing Xue,Zhiqiang Dong,Mingtao Ding,Rui Chen,Qiang Yang,Tao An,Xueqin Shao,LiLi Wang
Given the increase in global threats to the environment and the growth in energy demand, there is great interest in developing renewable and green biochar-based materials. This article investigated ball-milled cellulosic biochar-based composites incorporating minerals (montmorillonite, calcite , or quartz) synthesized by an in situ carbon-bed pyrolysis method. The synthesized samples were examined using X-ray powder diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM), N 2 adsorption/desorption isotherms, Fourier transform infrared spectroscopy (FTIR), thermogravimetry-differential thermal analysis (TG-DTA), Raman spectroscopy , and organic dyes adsorption analysis. It was shown that the mineral components incorporated during ball-milling modified the microstructure, morphology, and surface properties of biochar composites. Synergistic effects of oxygen functional groups and mesoporous layered structure contributed to the functionalization and surface modification of biochar-based montmorillonite composites, as reflected by a remarkably enhanced adsorption performance of organic dyes. Freundlich isotherm and pseudo-second-order kinetic models were found to provide an accurate description of the chemical adsorption of MB onto the heterogeneous surface of the biochar-based montmorillonite composite via cation exchange.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Lu Luo,Yalan Zhou,Wen Yan,Xi Wu,Shirui Wang,Weigang Zhao
A series of nitrogen and boron co-doped porous carbon composites (BNCs) were obtained using quick, easy and environmentally microwave-assisted hydrothermal treatment combined with a pyrolysis process subsequent. Biomass waste of fir bark is used as the carbon precursor, while ammonium pentaborate tetrahydrate is used as both boron (B) and nitrogen (N) source. The synthesis process and characteristics of the developed BNCs are investigated, and the results show that the N and B is successfully doped, generating a synergetic effect on the structure, surface characteristics and electrochemical properties. The BNCs achieves specific surface area up to 955 m 2 g −1 with mainly microporosity, and possess 10–13 % of B and 15~20 % of N content. The gravimetric capacitance values for the electrodes containing BNC-20 active materials is 188 F g −1 at 0.5 A g −1 , 2 times that of non-doped carbon, while maintaining 90% capacitance retention capability after 10,000 charge/discharge cycles. Furthermore, the assembled symmetric cell yielded high performance of volumetric capacitive of 91 F cm −3 at 0.5 A g −1 , superior energy density of 9.33 Wh kg −1 at 400 W kg −1 with 91% capacitance retention after 10,000 charge/discharge cycles at 1 A g −1 . Our work offers a potential relatively low-cost, effective and environmentally design of heteroatoms doped electrode materials with enhanced supercapacitors performance.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Kun Wang,Yuebing Sun,Jingchun Tang,Juan He,Hongwen Sun
A novel ball milled Fe 0 -biochar composite was synthesized by ball milling the mixture of biochar (pyrolyzed at 300 °C, 500 °C, and 700 °C) and micron grade iron powder. FTIR, SEM , TEM-EDS, XRD , and XPS were applied to characterize this composite. XRD results showed that iron carbide phase was formed during the ball milling process. The ability of this synthesized composited to remove aqueous Cr(VI) was tested. Removal rates of Cr(VI) (49.6%, 65.8%, and 97.8%, respectively) by ball milled Fe 0 -biochar composite consisting of biochar pyrolyzed at 300 °C (300BMFe 0 -BC), 500 °C (500BMFe 0 -BC), and 700 °C (700BMFe 0 -BC) were much higher than those (19%, 11%, and 4%, respectively) by pristine biochar pyrolyzed at 300 °C (300BC), 500 °C (500BC), and 700 °C (700BC). Cr(VI) removal rate by 700BMFe 0 -BC increased from 15.4% to 97.8% when prolonging ball milling time from 6 h to 48 h. Ball milling promoted the combination of Fe 0 and biochar as well as reduced the hydrodynamic diameter of the composite. Acidic conditions favored Cr(VI) removal. Ball milling exposed the functional groups of biochar and improved its Cr(VI) removal rate. Raman spectra showed that the degree of graphitization in 700 °C ball milled biochar (700BMBC) was the highest. Electrochemical analysis demonstrated that 700BMBC had the highest electron transfer capacity. In the presence of Fe 0 , graphitized structure in 700BMBC acted as an electron conductor, facilitating electron transfer from Fe 0 to Cr(VI). Ball milling also destroyed the surface iron oxide layer to regenerate the composite.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Shizong Wang,Jianlong Wang
This study prepared the carbon-supported cobalt catalyst (Co-C-X) for activating peroxymonosulfate (PMS), and investigated the effect of co-pyrolysis temperature of graphitic carbon nitride (g-C 3 N 4 ) and vitamin B 12 on the catalytic activity. It was found that with the increase of co-pyrolysis temperature, the catalytic activity of Co-C-X increased, due to the different coordination structures of cobalt. At 500 °C (Co-C-500), cobalt existed as CoO; while it was single atom Co at 600 °C (Co-C-600); and small size CoO at 700 °C (Co-C-700). Co-C-X could activate PMS to produce hydroxyl radicals, sulfate radicals, high-valent cobalt-oxo and singlet oxygen, which depended on the pyrolysis temperature. Although Co-C-700 had the highest catalytic activity, the leaching cobalt was also highest (3.23 mg/L), compared with that of Co-C-500 (0.27 mg/L) and Co-C-600 (0.14 mg/L). Co-C-600 had fast degradation for atrazine, nitrobenzene , bisphenol A, phenol and 4-chlorophenol, which also had wide pH range and high tolerance to inorganic ions.
✓ 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
FUEL
·
2023
·
IF 7.4
Yongbo Yu,Xiaohua Li,Shanshan Shao,Pengfei Zhang,Jiaxin Jiang
Biomass pyrolysis and in-line steam reforming for hydrogen production is one of the effective ways to promote the sustainable development of global energy. In this study, Co was recovered from the cathode material of LiCoO 2 batteries using the carbon thermal reduction method, and used for biomass pyrolysis and in-line steam reforming for hydrogen production. First, the cathode material was reduced using coconut shell carbon (CC), and it was revealed that cobalt presented in the catalyst prepared at the reduction temperature of 800 °C, giving the hydrogen yield of 24.9 mmol/g. Other carbon source like graphite carbon (GIC) and straw pyrolytic carbon (SC) were then investigated and it was found that a much higher temperature (>800 °C) was required for the reduction of the cathode material with GIC and the catalyst prepared by SC reduction was less effective than that using CC reduction. Considering the great influence of the pore structure of the carbon material on the reduction, activated carbon (AC) was obtained from SC using KOH activation. With a better distribution of cobalt on the carrier prepared by AC reduction, the highest hydrogen yield of 28.3 mmol/g was achieved with the mass ratio of cathode material and AC of 10:3. This study provides a viable avenue for the application of spent lithium-ion battery cathode materials in the production of hydrogen from biomass.
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Zhisen He,Shanjian Liu,Wenjing Zhao,Jia Liu,Dongmei Bi
Here, cellulose loaded with Ca and K was subjected to nitrogen-rich pyrolysis to investigate how alkali and alkaline earth metals affected its properties and the structural transformation of target products, especially the nitrogen transformation mechanism. Ca significantly reduced the activation energy of nitrogen-rich pyrolysis. The effect of Ca on the component distribution of bio-oil was significantly stronger than that of K. At Ca-0.5, the bio-oil had the highest content of nitrogen-containing compounds (77.98%), and the content of nitrogenous heterocyclic compounds (37.98%) was significantly higher than that of Ca-K-0 (27.75%). Ca and K promoted the production of pyridines. K acted on pyrroles and pyrazoles , while Ca acted on pyrazines . As Ca and K increased, both nitrogen-containing functional groups and nitrogen were enriched in biochar. Ca enhanced the H/C value of biochar and accelerated the conversion of char-N to tar-N. K tended to produce nitrogen-rich biochar with higher graphitization degree and stability.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Hongyan Wang,Xinyue Sun,Yurou Zhou,Bofeng Zhang,Jingpei Cao,Guozhu Liu
To further explore the decomposition behaviors of C5 cyclic hydrocarbons, important components in the transportation fuels and pivotal intermediates in high-density liquid fuels, the pyrolysis of cyclopentane, cyclopentene and cyclopentadiene with different unsaturation degrees were investigated. The experiments of cyclopentane and cyclopentene were performed at 1.0, 30.0 atm and 773–1173 K in a flow tube reactor. The mole fraction profiles of pyrolysis species, involving C1-C5 small hydrocarbons and monocyclic, bicyclic as well as polycyclic aromatic hydrocarbons (MAHs, BAHs and PAHs), were provided. A universal kinetic model for three C5 cyclic fuels pyrolysis chemistry was proposed and reasonably predicted the speciation profiles newly reported in this work and literature, where rate coefficients of the crucial reactions were compared and upgraded. The differences among three fuels specific pathways were evaluated and the effects of unsaturation on the pyrolysis characteristics of intrinsic reactivity and aromatics formation were revealed. Cyclopentene has the highest pyrolysis reactivity, followed by cyclopentane and cyclopentadiene. Simultaneously formed fuel radicals and key intermediates in three C5 cyclic fuels influence the formation channels of small products, MAHs and BAHs. The saturated cyclopentane is easily occur the ring-opening reaction to generate more C2 and C3 species, whereas the increase in unsaturation promotes MAHs and BAHs formation in cyclopentene and cyclopentadiene pyrolysis, especially the toluene, styrene, indene and naphthalene. The rate of production analysis shows the formations of these MAHs and BAHs are strongly dependent on the concentration levels of cyclopentadienyl resonance stabilized radical (RSR). Differently, the dominated growth pathways of three- and four-ring PAHs are barely influenced by the specific fuel chemistry and indenyl plays a crucial role via the typical RSR chain reactions at high pressures.
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Xiaohua Li,Haowen Fu,Shanshan Shao,Yixi Cai
Templating agents were created by utilizing several methods to handle natural cellulose (bagasse), and they were successfully used to treat HZSM-5 to introduce extra mesopores . In addition, the hierarchical HZSM-5 was employed in the catalytic pyrolysis of biomass to produce hydrocarbon fuels. The hydroxyl content in the templating agent could be promoted via hydrothermal and ultrasound-assisted treatment, improving their performance as templates to produce mesopores. The cellulose content in the templating agents was effectively boosted via hydrothermal-assisted treatment, whereas their relative crystallinity was improved by ultrasound assistance. The formation of mesopores was promoted with the increased cellulose content in the templating agents, and the catalytic performance in upgrading pyrolysis gas for aromatic hydrocarbons could be significantly improved. Higher relative crystallinity was advantageous for enhancing the stability of the templating agent in the catalyst synthesis system, and the formation of pore structures of the catalyst was promoted. Among all catalysts synthesized, catalysts synthesized by hydrothermal-assisted treatment (Cat-H(X)) presented the highest specific surface area and average pore size of 397.60 m 2 /g and 4.53 nm, which were about 1.41 and 1.98 times of commercial HZSM-5 (H-Z). The highest yield of BTX obtained with Cat-H(X) was 8.7 wt%, 1.81 times that obtained with H-Z.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Yuxiang Chen,Chao Li,Lijun Zhang,Qifeng Chen,Shu Zhang,Jun Xiang,Song Hu,Yi Wang,Xun Hu
The interaction between volatiles and homologous and/or heterologous char is almost inevitable during the transfer or diffusion of volatiles from inner core to outer surface of a biomass particle in pyrolysis . This shapes both composition of volatiles (bio-oil) and property of char. In this study, the potential interaction of lignin- and cellulose-derived volatiles with char of varied origin was investigated at 500 °C. The results indicated that both the lignin- and cellulose-char promoted polymerization of the lignin-derived phenolics, enhancing production of bio-oil by ca. 20%–30%, generating more heavy tar but suppressing gases formation, especially over cellulose-char. Conversely, the char catalysts, especially the heterologous lignin-char, promoted cracking of the cellulose-derivatives, producing more gases while less bio-oil and heavy organics. Additionally, the volatiles-char interaction also led to gasification of some organics and also aromatization of some organics on surface of char, resulting in enhanced crystallinity and thermostability of the used char catalyst, especially for the lignin-char. Moreover, the substance exchange and formation of carbon deposit also blocked pores and formed fragmented surface dotted with particulate matters in the used char catalysts.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）