Molecular Catalysis
·
2018
·
IF 0
Shanshan Jie,Congqiang Yang,Yuan Chen,Zhigang Liu
The highly dispersed active sites are desirable to optimize the atom efficiency. In this study, a series of novel cobalt grafted in N-doped carbon (Co-N-C) catalysts for selective oxidation of ethylbenzene are synthesized by heating a solution of cobalt porphyrin and peptides in ionic liquids, which are also characterized by techniques such as FT-IR, XRD, SEM-EDX, HR-TEM, and XPS. The results show that the as-prepared catalysts have an attractive catalytic performance, namely, 40% of ethylbenzene conversion and 75% of selectivity to acetophenone. Especially, the activity and selectivity of the as-prepared catalysts remain almost similar even after the 10th run. Moreover, the modified-complexometry method is verified to improve the dispersion of metal active sites. The remarkable catalytic performance of the as-prepared catalysts is attributed to the highly dispersed active sites and strong interactions between Co and N species in Co-N x moieties.
研究领域:
催化
·
材料科学
·
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Qilei Yang,Ang Cao,Na Kang,Kang An,Zhao-Tie Liu,Yuan Liu
The catalyst for direct ethanol synthesis (DES) from syngas was investigated in this work, which is Co/La 2 O 3 -doped La 4 Ga 2 O 9 . The catalyst was prepared by using LaCo 1−x Ga x O 3 with perovskite phase as the precursor to intensify the interaction in the elements of Co, La and Ga. The catalysts were characterized by using XRD , H 2 -TPR, TEM , EDS, XPS , BET, ICP and TG techniques. This catalyst showed high selectivity to ethanol and excellent stability including excellent resistance to sintering and carbon deposition . It seems that the ethanol is generated in the interface between metallic Co and La 4 Ga 2 O 9 , and in the interface cobalt would be positively charged due to the interaction between Co nanoparticles and La 4 Ga 2 O 9 . The results and the related discussions indicate that Co/La 2 O 3 -doped La 4 Ga 2 O 9 catalyst is a promising catalyst for DES from syngas. Graphical abstracts.
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2017
·
IF 3.648
Ai-Rong Xu,Shuan Wen,Lin Chen
Novel cellulose solvents, MIM-[N 4444 ][CH 3 CH 2 COO], were developed by coupling N -methylimidazole (MIM) with tetrabutyl ammonium propionate ([N 4444 ][CH 3 CH 2 COO]). The solubilities of cellulose in MIM-[N 4444 ][CH 3 CH 2 COO] solvents were determined at 25 °C. The effect of MIM content on cellulose solubility and the possible dissolution mechanism of cellulose in MIM-[N 4444 ][CH 3 CH 2 COO] solvent have been investigated. It was found that [CH 3 CH 2 COO] − anion in MIM-[N 4444 ][CH 3 CH 2 COO] solvent is the main driving force of the cellulose dissolution by interacting with the hydroxyl hydrogen atom in cellulose, and the role of MIM is mainly to disassociate/dilute [N 4444 ][CH 3 CH 2 COO]. In addition, the morphology and structure of the regenerated cellulose materials from MIM-[N 4444 ][CH 3 CH 2 COO] solvent were characterized by scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD).
研究领域:
材料科学
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化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
Wood Material Science & Engineering
·
2023
·
IF 2.2
Zhiping Wang,Anmin Huang,Shifeng Zhang,Yingying Su,Yuejin Fu
Wood emits volatile organic compounds (VOCs) that can affect people’s health and air quality. Based on advanced oxidation processes (AOPs), sulfate radicals produced via thermally-activated persulfate (Na2S2O8, KHSO5) can minimize VOCs. This research aims to apply this technique to minimize the VOC content in Pinus radiata. The results showed that terpenes and alcohols were the main VOCs emitted from Pinus radiata, which were greatly minimized using four treatments; however, acetic acid and 3-furaldehyde emissions increased. Furthermore, the temperature and oxidizing agent contributed to VOC degradation. Characterization results, including FTIR, XRD, color tests, and compressive strength indicated that the AOP treatment caused only a slight decline in the wood properties, while effectively reducing VOC emissions by as much as 32.75–61.05%.
研究领域:
环境科学
·
材料科学
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化学工程
·
林业
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 14
·期 1
·18
·
IF 3.9
Kaixuan Chen,Linsheng Xu,Yuanfeng Li,Jing Xiong,Dawei Han,Yaxiao Ma,Peng Zhang,Haoqi Guo,Yuechang Wei
Herein, we present an in-depth investigation into the enhancement of catalytic soot oxidation through cerium-doped three-dimensional ordered macroporous (3DOM) La-Co-Ni-based perovskites synthesized with the colloidal crystal template (CCT) method. The 3DOM structure significantly contributes to the accessibility and interaction efficiency between soot and catalyst. Based on the results of powder X-ray diffraction (XRD), N2adsorption-desorption measurements, scanning electron microscopy (SEM), temperature-programmed oxidation of NO (NO-TPO), temperature-programmed reduction of H2(H2-TPR), in situ infrared Fourier transform spectroscopy (In-situ DRIFTS), and temperature-programmed oxidation (TPO) reactions, the role of cerium doping in modifying the structural and catalytic properties of 3DOM perovskite-type La2−xCexCoNiO6catalysts was investigated systematically. The optimized cerium doping ratio in La2−xCexCoNiO6catalysts can improve the microenvironment for efficient soot-catalyst contact, enhancing the catalytic activity of soot oxidation. Among the catalysts, the 3DOM La0.8Ce1.2CoNiO6catalyst shows the highest catalytic activity for soot oxidation, whose T10, T50, and T90values are 306 °C, 356 °C, and 402 °C, respectively. The mechanism of the cerium doping effect for boosting soot oxidation is proposed: The doping of Ce ions can increase the surface oxygen species, which is the main active species for promoting the key step of NO oxidation to NO2in catalyzing soot oxidation. This research provides a new strategy to develop high-efficient non-noble metal catalysts for soot oxidation in pollution control and sustainable environmental practices.
研究领域:
催化
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qianqian Chen,Xiaobing Yang,Xingping Fu,Junjie Pan,Junmei Zhou,Gengwu Zhou,Kejun Cheng
Currently, antibiotics are extensively utilized in the pharmaceutical industry to assist humans and animals in combating various infectious diseases. The extensive use of various antibiotics enhances the quality of life. However, it can also have negative effects on the environment and human health, including water pollution and the rise of antibiotic-resistant microorganisms. To date, antibiotics have been detected in rivers, groundwater, and even drinking water. There is an urgent need to design and develop advanced materials for the remediation of antibiotics present in our environment. In this paper, we successfully synthesized a novel Ag 2 S-ZnS/ZIF-8 hollow heterojunction via facile sulphuration and solvothermal methods. This heterojunction was employed as a catalyst for the degradation of tetracycline (TC) in water under UV and visible light irradiation. The physicochemical properties of the as-synthesized catalysts were thoroughly analyzed using XRD, EDS, SEM, BET, XPS, TEM, ESR, UV–vis techniques. The results demonstrate that Ag 2 S-ZnS/ZIF-8 displays enhanced photocatalytic activity for TC degradation no matter under visible or UV light irradiation. After 10 min of UV light irradiation, its photocatalytic degradation efficiency was achieved 92.74 %. Additionally, Ag 2 S-ZnS/ZIF-8 was able to degrade 92.14 % of TC (visible light, with 35 min). The corresponding kinetic rate constant of Ag 2 S-ZnS/ZIF-8 is 0.145 min −1 (UV light) and 0.043 min −1 (visible light), respectively. Furthermore, Ag 2 S-ZnS/ZIF-8 also shown excellent stability for the degradation of TC in the presence of visible light. This is a result of its high specific surface area, superior photocurrent and efficient separation of photo-generated electrons-hole pairs. Apart from this, the photocatalytic degradation mechanism of TC over Ag 2 S-ZnS/ZIF-8 is discussed in detail.
研究领域:
环境科学
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材料科学
·
化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2021
·Vol. 127
·期 10
·1-9
·
IF 2.584
Zhang Yu,Cao Ping,Lin Wei,Liu Qiang,Chen Ziyuan,Cao Jun,Yang Guannan,Cui Chengqiang
In this paper, a mixed sintering accelerator of colophony and cetyltrimethyl ammonium bromide (CTAB) was developed to improve the sintering properties of Cu nanoparticles (NPs) paste. With the synergy effect of the mixed sintering accelerator, Cu NPs paste could be well sintered at 260 °C for 30 min under a pressure of 2 MPa, and the shear strength was greatly improved from 15 to 33 MPa. The fracture morphology of the Cu NPs joint transformed from brittle interface failure features to ductile dimple features, and the porosity in the sintered layer was significantly reduced. XRD analysis further confirmed that the synergy of colophony and CTAB could effectively remove the oxides in the Cu NPs paste during sintering, and thereby improve the sintering properties. This work can provide an applicable approach to improve the sintering properties of metal NPs and help to understand the synergy effect of sintering accelerators on the bonding behaviors of metal nanoparticles at low temperatures. Graphic abstract
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Xiaoping Wu,Qiao Zhang,Lungang Chen,Qiying Liu,Xinghua Zhang,Qi Zhang,Longlong Ma,Chenguang Wang
The development of thermally stable Pt-based catalysts with superior performance for propane dehydrogenation reactions remains a daunting challenge. In this study, a series of PtSn-Mg(Zn)AlO catalysts with different Zn and Pt contents were synthesized by the anion-exchange method for the propane dehydrogenation reaction. To investigate the influence of Zn on the reaction performance and the catalyst structure, the prepared catalysts were characterized with several analytical techniques, including XRD , TEM, HRTEM, H 2 -TPD and CO pulse chemisorption . A good propane conversion (initially higher than 55% and averaging 45.2% over a period of 2 h) and propene selectivity (higher than 99%) were obtained experimentally with PtSn-Mg(3Zn)AlO at 550 °C. The results demonstrated that Pt provided the active sites and that Zn was a promoter. The HRTEM and CO pulse chemisorption results indicated that the addition of Zn to the PtSn-MgAlO catalyst can stabilize the dispersion of metal particles and thus inhibit the sintering of Pt particles. Furthermore, the activities of the used catalysts were almost recovered through reaction-regeneration cycles with the burning-off of coke during five cycles.
研究领域:
催化
·
化工
·
材料科学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Yongchi Zhou,Tian Xu,Meifeng Xu,Yaoyao Yin,Yu Wang,Yonglong Jin,Chaonan Wang
In this work, Raman signals are used to characterize the crystallinity of perovskite films and the photoelectric conversion efficiency (PCE) of perovskite solar cells . By controlling the ratios of EtOH and CHCl 3 during the perovskite crystallization process , the CH 3 NH 3 PbI 3 film with larger crystal grain size , higher crystallinity and no pinholes can be obtained. Good crystallinity of perovskite films promotes charge transfer (CT), and Raman spectroscopy is a practical method for the real time detection of CT in perovskite films. The results manifest that SERS intensities are conforming to X-ray diffraction (XRD) intensities and the PCE of perovskite solar cells . Meanwhile, the Raman signals are tested in the nitrogen environment, which can avoid the decomposition of perovskite films caused by H 2 O and O 2 . These results indicate that this method provides an early, real-time and harmless method to study the performance of perovskite photovoltaic devices .
研究领域:
材料科学
·
光子学
·
光谱学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Xiaojun Dai,Yan Cheng,Tingting Liu,Lingjuan Mao,Qiang Wei,Yasong Zhou
SAPO-11 molecular sieves with different crystal sizes and particle sizes, especially nanosized small-crystal SAPO-11 molecular sieves, were successfully synthesized, and the corresponding NiWS-supported catalysts were prepared for the hydroisomerization of n-hexadecane. XRD, SEM, N2 adsorption–desorption, Py-IR, and HRTEM were used to analyze the effects of crystal size and particle size of the supports on their physicochemical properties, active phase properties, and catalytic performance of the catalysts. Through reaction evaluation and analysis of isomeric products, the effects of the size change of the support on the hydroisomerization performance of the catalyst and the hydroisomerization depth of n-hexadecane were determined. Through comprehensive analysis of the cracking products, it was determined that secondary cracking occurred when the conversion of n-hexadecane on the NiW/SAPO-11-S catalyst reached about 42.7%, and the secondary isomerization occurred when the conversion of n-hexadecane reached about 80%. The hydroisomerization reaction network of n-hexadecane over the NiWS/SAPO-11 catalyst was studied emphatically, and it was found for the first time that the secondary cracking of n-hexadecane during hydroisomerization followed the C3-β-scission mechanism.
研究领域:
化学工程
·
催化
·
材料科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Aijuan Xie,Jiawen Du,Feng Tao,Yuwei Tao,Zhichen Xiong,Shiping Luo,Xiazhang Li,Chao Yao
A novel three-dimensional graphene surface-mounted nickel-based metal organic framework (3D Gr/Ni-MOF) electrocatalyst was fabricated via freeze-drying technique and ultrasonic assisted method. The morphology, elemental composition , crystal structure, functional group structure, specific surface area and pore size of the composite were analyzed by SEM, EDS, XRD, FTIR, and BET. A series of conditional experiments from the aspects of organic ligand screening, ultrasonic time, molar ratio of metal salt to ligand, and porous graphene loading were carried out to optimize 3D Gr/Ni-MOF composite. Oxygen Evolution Reaction (OER) catalytic performance, OER process kinetics, stability and the deeper causes of enhanced OER performances of 3D Gr/Ni-MOF were also investigated via a group of electrochemical methods. The experiment results showed that 3D Gr/Ni-MOF composite prepared with 2,5-pyridinedicarboxylic acid as ligand, 1:1 M ratio of nickel acetate to ligand, 10 mg of 3D Gr loading and 8 h of ultrasonic process exhibited the most excellent OER activity. Its overpotential of 370 mV was much smaller than rGO/Ni-MOF, Ni-MOF and 3D Gr prepared under the same conditions, and as non-precious metal catalyst , it has the traits of low cost, easy preparation, high activity and durable stability.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Xuesheng Liu,Xueli Li,Xuewei Liu,Sisi He,Junsu Jin,Hong Meng
To improve the photocatalytic performance of ZnO nanoparticles , based on the collective effect as electron sink of Ag and perfect two-dimensional (2-D) feature of graphene, Ag-ZnO-rGO nanoparticles were prepared by polyvinyl alcohol assisted freeze-drying and subsequent hydrothermal reduction method. Through photocatalytic degradation of methyl orange solution under UV irradiation , all as-prepared samples were assessed and compared with those of published works. The surface morphology , microstructure and optical property of materials were systematically studied by XRD , XPS , SEM , TEM and DRS , respectively. XPS and Raman spectra results confirmed that GO has successfully been reduced to rGO; SEM and TEM characterizations manifested that Ag-ZnO NPs were uniformly distributed in rGO with two-dimensional sheets structure; DRS characterization and Kubelka-Munk formula calculation illustrated that Ag-ZnO-rGO exhibited the smallest band gap and the best optical absorption performance. Moreover, the photocatalytic degradation results indicated that Ag-ZnO-rGO NPs combine the advantages of graphene and Ag which not only has significant adsorption but also maintains high photoreactivity.
研究领域:
材料科学
·
环境科学
·
纳米技术
✓ 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）