INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
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IF 7.139
Zhipeng Tian,Weijie Zhang,Tao Liu,Jianping Liu,Chenguang Wang,Libin Lei,Mingzheng Liao,Chao Wang,Ying Chen
Hydrogen production by catalytic aqueous phase reforming (APR) of biomass-derived oxygenates is a promising route to produce hydrogen in a renewable way. As the typical APR catalyst, Pt/Al 2 O 3 is confronted with high methanation activity that consumes H 2 and produces undesired CH 4 during the treatment of methanol solution. In contrast, WGS reaction is the main pathway to boost H 2 generation during APR process. In this work, a series of PtFe/Al 2 O 3 catalyst with different Fe contents were prepared, characterized and tested for the methanol APR reaction. XRD , TEM, XPS and H 2 -TPR technologies were applied to study the change of physicochemical properties with the addition of iron. The restriction on methanation and promotion on WGS reaction were proved as well. With the increase of Fe content, the interaction between Pt and FeO x species have both positive and negative effects on APR reactivity while the CH 4 selectivity descending continuously from 9.25% to as low as 0.60%. Besides, the effects of reduction temperatures (250–350 °C) of Pt0.5Fe/Al 2 O 3 catalyst on APR performances were also investigated. An “Oxygen dynamic transfer cycle” between H 2 O/CO∗ and FeO x species with oxygen vacancies is proposed and verified. This indirect WGS reaction through lattice oxygen on FeO x species that boosting WGS reactivity helps improving H 2 selectivity in the gas products of methanol APR.
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高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Duan Ying,Wang Rui,Liu Qihang,Qin Xuya,Li Zuhuan
The conversion of 5-hydroxymethylfurfural (HMF) to 1-hydroxy-2,5-hexanedione (HHD) represented a typical route for high-value utilization of biomass. However, this reaction was often catalyzed by the noble metal catalyst. In this manuscript, W promoted Ni/Al2O3 was prepared as a noble-metal-free catalyst for this transformation. The catalysts were characterized by XRD, XPS, NH3-TPD, TEM, and EDS-mapping to study the influence of the introduction of W. There was an interaction between Ni and W, and strong acid sites were introduced by the addition of W. The W promoted Ni/Al2O3 showed good selectivity to HHD when used as a catalyst for the hydrogenation of HMF in water. The influences of the content of W, temperature, H2 pressure, reaction time, and acetic acid (AcOH) were studied. NiWOx/Al2O3-0.5 (mole ratio of W:Ni = 0.5) was found to be the most suitable catalyst. The high selectivity to HHD was ascribed to the acid sites introduced by W. This was proved by the fact that the selectivity to HHD was increased a lot when AcOH was added just using Ni/Al2O3 as catalysts. 59% yield of HHD was achieved on NiWOx/Al2O3-0.5 at 393 K, 4 MPa H2 reacting for 6 h, which was comparable to the noble metal catalyst, showing the potential application in the production of HHD from HMF.
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高影响因子
CERAMICS INTERNATIONAL
·
2023
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IF 5.2
Yue Gu,Wenyan Duan,Tongcai Wang,Xiaodong Liu,Shan Li,Bingshan Liu,Gong Wang
Ceramic cores are essential intermediate mediums in casting superalloy hollow turbine blades. The developing of additive manufacturing (AM) technology provides a new approach for the preparation of ceramic cores with complex structure. In this study, alumina oxide (Al 2 O 3 ) ceramic cores with fine complex geometric shapes were fabricated by digital light processing (DLP) in high resolution. The maximum solid content of 70 vol% of ceramic slurry was adopted in the printing process, which is important for the regulation of deformations and mechanical properties . The effects of the printing parameters, including exposure intensity, printing layer thickness and sintering temperature on the microstructures and mechanical properties of printed samples were investigated. The decrease of residual stress and similar shrinkage in X, Y, and Z directions could be obtained by adjusting the printing parameters, which are crucial to prepare complex ceramic cores with high quality. Besides, the flexure strength and open porosity of ceramic cores reached 34.84 MPa and 26.94%, respectively, which were supposed to meet the requirement of ceramic cores for the fabrication of superalloy blades.
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高影响因子
SOLAR ENERGY
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2023
·
IF 6.7
Mengting Ji,Laiquan Lv,Jingwen Liu,Yan Rong,Hao Zhou
The coefficient of thermal expansion of inorganic salts increases with increasing temperature. The sintering temperature may affect the properties of the shape-stable phase change materials (SSPCMs). We study the SSPCMs with NaNO 3 -KNO 3 as the phase change material and Al 2 O 3 and expanded graphite (EG) as the skeletal support materials (SSMs) to achieve thermal energy storage over a wide temperature range. The effects of different sintering temperatures on the SSMs content, thermal conductivity and compressive strength of SSPCMs were studied. The results showed that as the sintering temperature increased, more SSMs were required to support the SSPCMs. The maximum NaNO 3 -KNO 3 mass percentages of the SSPCMs sintered at 300 °C and 450 °C were 82.8 wt% and 66.4 wt%, respectively. Samples with application temperatures higher than the sintering temperature may have problems stabilizing the shape. Sintering temperature had little influence on the thermal conductivity of the same SSPCMs. However, the compressive strength of the SSPCMs decreased with increasing sintering temperature. The addition of EG decreases the decomposition temperature of the composite and limits its application temperature range. The SSPCM-10/30 sintered at 450 ℃ showed good chemical stability performance, and the latent heat decreased from 56.01 J/g to 53.44 J/g. The compressive strength dropped from 30.7 MPa to 25.17 MPa before and after 20 cycles due to larger internal gaps and did not change much after 20 cycles.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
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2023
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IF 4.7
Wenfei Yang,Shuzheng Wu,Cejun Hu,Hongwei Zhang,Qingyan Cui,Xiaojun Bao,Pei Yuan
The hydrogenation of unsaturated bonds and elimination of sulfur impurities in C 9 petroleum resin (C 9 PR) are crucial for improving its quality and performance. In this study, we prepared a nanoflower-like Ni 2 P/Al 2 O 3 catalyst using an in-situ synthesis combined with liquid-phase phosphidation strategy and applied for the production of value-added hydrogenated C 9 PR. In-situ synthesis of Ni-Al hydrotalcite anchors and disperses Ni nanoparticles, while liquid-phase phosphidation introduces high-content Ni δ+ and P δ− active sites and prevents the formation of inactive AlPO 4 , synergistically enhancing both hydrogenation and desulfurization activities. The synthesized Ni 2 P/Al 2 O 3 catalyst achieves a 99.6 % hydrogenation degree and reduces sulfur content from 137 ppm to 0 ppm, much better than the catalysts prepared by conventional impregnation and metal phosphate reduction methods. These results give valuable insights for designing efficient catalysts and advancing single-step hydrorefining processes to generate high-quality, value-added hydrogenated petroleum resins.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2026
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IF 9.6
Mengxiang Liu,Kaifu Yang,Jiale Fan,Kaibo Yu,Zihan Kong,Tao Zhang,Xiaoxiao Huang
Al 2 O 3 -mediated interface engineering builds multifunctional MXene composites. • Heterogeneous interfaces regulate dielectric response and thermal insulation. • Optimized composite achieves −62.76 dB RL min with excellent thermal insulation. Developing lightweight multifunctional materials that integrate efficient microwave absorption and thermal insulation remains a significant challenge for advanced electromagnetic protection applications. Herein, Al 2 O 3 -mediated MXene-derived TiO 2 /N-doped carbon composites (AMNC) were engineered via a facile freeze-drying/thermal treatment strategy. During fabrication, in situ generated Al 2 O 3 nanorods established abundant heterogeneous interfaces with MXene-derived TiO 2 and the N-doped carbon framework, constructing a hierarchical interface architecture that effectively regulated dielectric behavior. The synergistic effects of enhanced interfacial polarization, optimized conductive networks, and improved impedance matching endowed the AMNC composites with superior electromagnetic wave attenuation capability. The optimized AMNC-1 achieved a minimum reflection loss (RL min ) of −62.76 dB at a thickness of 2.43 mm and a maximum effective absorption bandwidth (EAB max ) of 5.12 GHz at only 1.88 mm. The corresponding specific reflection loss values (SRL l and SRL lt ) reached 313.80 and 129.14, respectively, demonstrating excellent lightweight microwave absorption capability. Furthermore, CST simulations revealed a radar cross-section reduction of 34.62 dB m 2 under normal incidence, indicating promising radar stealth capability. Owing to the interconnected porous structure and Al 2 O 3 -mediated heterogeneous interface architecture, AMNC-1 exhibited excellent thermal insulation performance, maintaining a surface temperature of only 51.5 °C after heating on a 100 °C hot plate for 30 min. This work highlights the critical role of Al 2 O 3 -mediated heterogeneous interfaces in tailoring dielectric response and thermal insulation behavior, providing a rational strategy for designing lightweight multifunctional composites with synergistic electromagnetic absorption and thermal insulation performance. Download: Download high-res image (204KB) Download: Download full-size image
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高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Zilong Zhao,Shuyu Qi,Jianli Zhou,Yatao Ren,Kaiyun Zheng,Jin Zhang,Wenyi Dong,Hongjie Wang
To enhance the polarization distribution of electron cloud density on the catalyst surface, we have introduced a novel bimetallic-substituted dual-reaction center (DRC) catalyst (FeCo-γ-Al 2 O 3 ) comprising iron (Fe) and cobalt (Co) for the decomplexation and mineralization of heavy metal complex Ni-EDTA in this study. Compared to the catalysts doped solely with Fe or Co, the bimetal-doped catalyst offered several advantages, including enhanced electron cloud polarization distribution, additional electron transfer pathway, and improved capacity of free radical generation. Through DFT calculations and EPR tests, we have elucidated the influences of the catalyst's adsorption toward Ni-EDTA and its decomplexation products on the electron transfer between the pollutant and the catalyst. The competition between the pollutants and H 2 O 2 affects the generation of free radicals in both electron-rich Fe and Co centers as well as electron-deficient Al center. Building on these findings, we have proposed a plausible removal mechanism of Ni-EDTA using the heterogeneous Fenton-like catalyst FeCo-γ-Al 2 O 3 . This study sheds light on the potential of FeCo-γ-Al 2 O 3 as a DRC catalyst and emphasizes the significance of pollutant characteristics in determining the catalyst's performance.
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Surfaces and Interfaces
·
2023
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IF 6.2
Tingyu Chen,Shuaiqi Zhao,Jiajin Lin,Yanan Chong,Yifei Li,Yun Zhao,Guangxu Chen,Yongcai Qiu
As a nontoxic and cheap catalyst, the Al 2 O 3 catalyst can be used to catalyze the propane dehydrogenation (PDH) process. However, due to its poor activity, it has been used as a catalyst carrier rather than catalysis. In this work, the experimental results indicate that γ- Al 2 O 3 -(110)-S catalysts can improve the yield of propane dehydrogenation more effectively than γ-Al 2 O 3 -(110) catalyst. We investigate the potential barrier of propane dehydrogenation reaction catalyzed by Al 2 O 3 -(110) under different conditions and found that the substitution of the S atom for partial O atom can modify the acid-base properties of the surface active site of γ-Al 2 O 3 -(110), thus reducing the reaction energy barrier. In particular, the yield of the reaction can be further improved by the active sites of oxygen vacancies generated by removing partial S atoms in γ-Al 2 O 3 -(110)-S, which is consistent with our theoretical calculation results. At the same time, theoretical calculation shows that Cu clusters can effectively remove the S atoms on the surface of γ-Al 2 O 3 -(110)-S and form oxygen vacancies. This strategy provides a new path to form oxygen vacancies on γ-Al 2 O 3 -(110), which opens up a new way for the study of propane dehydrogenation.
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Scientific Reports
·
2021
·Vol. 11
·期 1
·1-13
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IF 4.38
Tang Xi,Zhang Yifei,Li Weiqi,Geng Jinju,Ren Hongqiang,Xu Ke
Humic acid (HA) is the main component of organic matter in effluent from wastewater treatment. The effective removal of HA is significant. In this study, a novel catalyst was prepared using a transition metal oxide as the active component and Al 2 O 3 as a granular carrier. The mechanism of catalytic ozonation of HA under neutral pH conditions and its efficiency were investigated. Under the chosen conditions (an ozone concentration of 2.2 mg/L, 50 mg/L HA solution, catalyst dosage of 5 g/L and initial pH of 6.49), the Cu/Ce–Al 2 O 3 bimetallic catalyst led to 54.79% TOC removal rate after 30 min; the removal rate by ozone alone was only 20.49%. The characteristics of organic compounds determined by FT-IR and GC–MS showed that organic compounds were degraded significantly by the catalytic treatment. The addition of catalysts could effectively degrade toxic intermediates and reduce the acute toxicity produced by ozonation. Humic acid substances were largely removed and transformed into biodegradable intermediates. This study proposes a new and efficient ozonation catalyst for practical applications in advanced wastewater treatment.
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Catalysis Science & Technology
·
2020
·Vol. 10
·期 8
·2343-2352
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IF 5.721
Ziheng Zhen,Wenxiang Tang,Wei (Willy) Chu,Tao Zhang,Li Lv,Shengwei Tang
The dispersity and the neighboring degree of different sites play crucial roles in the catalytic performance of dual site catalysts. The solution of precursors was encapsulated into microdroplets by forming a microemulsion. The average diameter of microdroplets was about 45 nm. This guaranteed that the dosage of precursors was at the attogram level and only about a thousand precursor molecules were encapsulated in each microdroplet. An anti-solvent extraction method was applied to extract water from the microdroplets with acetonitrile. The precursors co-precipitated in the microdroplets due to the loss of water. The encapsulated precursors in the microdroplets co-precipitated together in nanoscale space, so the neighboring degree of the two precursors was improved significantly. The prepared catalyst was characterized by ICP-OES, BET, XRD, H2-TPR, TEM and XPS. Compared with the Cu–ZnO/Al2O3 (CZA) catalysts prepared by the conventional impregnation method, the CZA catalysts prepared by the proposed strategy had much stronger interaction and a better neighboring degree of the dual active sites. They also showed very good catalytic performance for the reverse water gas shift (RWGS) reaction. The CO2 conversion of the designed CZA catalysts was about 1–2 times higher than that of the CZA catalysts prepared by the conventional impregnation method at 0.1 MPa, 300–400 °C and a CO2/H2 mole ratio of 1.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 19
·8170-8184
·
IF 3.553
Duan Guangyu,Cao Yutong,Quan Jiayou,Hu Zuming,Wang Yan,Yu Junrong,Zhu Jing
This paper reports that a novel polyimide dielectric composite with three-dimensional (3D) thermally conductive networks and enhanced breakdown strength was firstly fabricated by filling with core-double-shell structured F-BA fillers. The F-BA particles were composed of nano-sized boron nitride (nBN) and polydopamine-coated spherical alumina (PDA@Al 2 O 3 ). Moreover, to ameliorate interfacial compatibility between F-BA fillers and PI matrix as well as restrain phonons scattering during propagation, 1,6-Diisocyanatohexane (HDI) was innovatively used as “bridge agent” to connect and functionalize nBN and PDA@Al 2 O 3 particles to generate core-double-shell structure. The results revealed that breakdown strength of PI dielectric composite with 25 wt % F-BA fillers was increased to 146.3 MV·m −1 , showing an increment of 68.5% in comparison with that of pure PI. Furthermore, the thermal conductivity of F-BA/PI composite with 25 wt % F-BA fillers increases to 6.41 W/m·K of in-plane direction and 1.01 W/m·K of through-plane direction, respectively, which shows 36 and 6 times higher than polyimide of 0.18 W/m·K. For dielectric properties of F-BA/PI composite, the dielectric constant and loss are less than 3.5 and 0.02, respectively. Considering these properties, the prepared PI dielectric composite shows potential application in high-performance electronic devices.
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Arabian Journal of Chemistry
·
2020
·
IF 4.762
Jiayao Li,Weifeng Song,Zefeng Yu,Qiuhua Li
The quality of dairy farming wastewater in different regions is particular and different. In Southern China, the Chemical Oxygen Demand (COD Cr ) and colourity of effluent from conventional dairy farming wastewater treatment processes are similar. Catalytic ozonation is a very promising technical method. In this paper, the Mn-Fe-Ce/γ-Al 2 O 3 catalyst was prepared via the optimized preparation method of impregnation roasting using γ-Al 2 O 3 as the carrier, and this catalyst was used in the ozonation of actual dairy farming wastewater from treatment facilities. The performance of the Mn-Fe-Ce/γ-Al 2 O 3 catalyst on dairy farming wastewater was investigated using a simulated dynamic test. The effects of the reaction time, pH and catalyst dosage on COD Cr and the colourity removal ratio were investigated. The results show that the optimum treatment conditions were a reaction time of 20 min, pH 9, and catalyst dosage of 15 g/L. The COD Cr removal ratio reached 48.9% and the colourity was 95% under the optimum conditions. BOD 5 /COD Cr increased from 0.21 to 0.54 after catalytic ozonation, indicating that the biodegradability of wastewater was significantly improved. This research provides a new method and theoretical guidance for dairy farming wastewater treatment.
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