FUEL
·
2024
·
IF 6.7
Xianjie Li,Bingxiao Feng,Hailin Zhang,Yaping Liu,Meng Xiao,Tingting Huang,Quanhong Zhu,Hongbing Song
Furfural, a key biomass-derived compound, can be transformed into high-value chemicals, including methyl furoate, through oxidative esterification. This process finds broad applications across various industries. In the current study, gold nanoparticles were deposited on γ-Al 2 O 3 pretreated with NaOH etching, utilizing the urea deposit-precipitation method followed by reduction in a hydrogen atmosphere. This approach resulted in a highly active Au catalyst, which was thoroughly characterized using multiple analytical techniques. The optimization of NaOH etching enhanced the pore structure and improved the dispersion of the active metal on the support. Notably, the Au/γ-Al 2 O 3 -2 catalyst, prepared with a 2-hour etching duration using 1 M NaOH, exhibited uniformly dispersed gold nanoparticles with an average size of 2.8 nm. The smaller particle size and enhanced dispersion of these Au nanoparticles significantly contributed to the catalyst’s superior catalytic activity and recyclability. Under optimized reaction conditions, the Au/γ-Al 2 O 3 -2 catalyst achieved nearly complete conversion of 1 mmol of furfural to methyl furoate within 4 h, with both conversion and selectivity exceeding 99 %. The study also proposed a mechanism for the oxidative esterification of furfural to methyl furoate catalyzed by Au/γ-Al 2 O 3 -2. Additionally, the catalyst’s effectiveness in the oxidative esterification of various substrates was investigated, demonstrating its robust activity for aromatic aldehydes and alcohols. This broadens the potential applications of the catalyst in the synthesis of diverse valuable esters.
研究领域:
催化化学
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生物质转化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Shenglin Kang,Xuetong Zhao,Jing Guo,Jie Liang,Jianjie Sun,Yang Yang,Lijun Yang,Ruijin Liao,Clive A. Randall
Thermal-assisted cold sintering process (TA-CSP) has been applied to fabricate high dense α-Al 2 O 3 ceramics with submicron grain sizes. The α-Al 2 O 3 (80 wt%) and γ-Al 2 O 3 (20 wt%) powders are firstly mixed and then cold sintered at 300 °C to produce a green bulk with a relatively high density of ∼ 86.9 %, and then later a second heat treatment (800–1350 °C) is applied to finally fabricate (∼ 98 % dense) α-Al 2 O 3 ceramics with grain sizes of 720 nm. A microstructural analysis with XRD and TEM suggests that the TA-CSP samples not only complete the final densification but also drive a phase transition of γ-Al 2 O 3 to α-Al 2 O 3 . To put into perspective the Hardness and Young's modulus of TA-CSP samples reach ∼ 14 GPa and ∼ 335 GPa, respectively, which is comparable to conventional sintered samples processed at higher temperatures of 1500–1700 °C. Therefore, it is feasible to utilize TA-CSP to prepare α-Al 2 O 3 ceramics with small grain sizes at low sintering temperatures .
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Wei-Tu Li,Xian-Yong Wei,Xue-Ke Li,Xiang-Xue Liu,Zhan-Ku Li,Zhi-Min Zong
Catalysts Ni/γ-Al 2 O 3 , Mg 2 Si/γ-Al 2 O 3 , and Ni-Mg 2 Si/γ-Al 2 O 3 were prepared. Their activities for catalytic hydroconversions (CHCs) of some lignite-related model compounds were examined. For the CHCs of oxydibenzene (ODB), benzyloxybenzene, and oxybis(methylene)dibenzene, the suitable loadings of Ni and Mg 2 Si are 33 and 20% in Ni-Mg 2 Si/γ-Al 2 O 3 , respectively, and the optimal reaction conditions are 4 MPa of initial hydrogen pressure, 240 °C, and 2 h, under which ODB was almost completely converted to cyclohexane. The formation of possible intermediates during the CHC of ODB was discussed. Ni-Mg 2 Si/γ-Al 2 O 3 was proposed to have 3 functions, i.e., activating H 2 to biatomic active hydrogen (H⋯H), releasing H − , and heterolytically splitting H⋯H to release H − as well, resulting in the hydrogenation of aromatic rings and the hydrocracking of C O bonds, respectively.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Liying Zeng,Yizhou Wang,Jun Mou,Fei Liu,Chunliang Yang,Tianxiang Zhao,Xiaodan Wang,Jianxin Cao
γ-Al 2 O 3 was composited with ZSM-5 molecular sieve to improve its catalytic performance and hydrothermal stability during the conversion of crude methanol into dimethyl ether (DME). When prepared by a liquid-phase coating chemical compounding, the ZSM-5/γ-Al 2 O 3 composite catalyst reached an excellent methanol conversion of 91.9% and DME selectivity of 100%. The DME yield was increased by about 13% compared to only using γ-Al 2 O 3 . Partial desiliconization and dealumination of the ZSM-5 molecular sieve effectively reduced the surface acid center strength and increased the mesoporous ratio. The special composite phase interface effectively decreased surface charge density of γ-Al 2 O 3 and formed the B (Brønsted) - L (Lewis) synergistic active centers. All these factors contribute to improving the catalytic performance, hydrothermal stability and resistance to deactivation of ZSM-5/γ-Al 2 O 3 during the conversion of crude methanol to DME.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Huang Meng,Huang Wenbin,Li Anqi,Yang Han,Jia Yijing,Yu Zhiqing,Xu Zhusong,Wang Xiaohan,Zhou Yasong,Wei Qiang
Experiments were carried out to research the different contents of Ga2O3 modification effects on the hydrodesulfurization (HDS) performance of 4,6-dimethyldibenzothiophene (4,6-DMDBT) catalyzed by the stepwise impregnation method. Characterization techniques such as XRD, BET, HRTEM, NH3-TPD, and Py-FTIR were performed to determine the effects of each modification of the catalyst by Ga on the properties of the prepared supports and catalysts. The catalytic effect of gallium is reflected in the fact that the empty d-orbitals of Ga elements participate in the formation of molecular orbitals in the active center and change their orbital properties, thus generating a direct desulfurization active phase suitable for complex sulfides for endpoint adsorption. The characterization results indicated that the introduction of Ga2O3 with appropriate content (2 wt.%) promoted Ni and Mo species to disperse uniformly and doping of more Ni atoms into the MoS2 crystals, which also increased the average stacking number and the length of MoS2. As a result, more NiMoS active phases were favored to form in the system. The specific surface area and the amounts of acid sites were increased, facilitating the adsorption of reactant molecules and the HDS reactions. The HDS results also suggested the effects of Ga modification play a very important role in the catalytic performance of the corresponding catalysts. The catalyst Ga–Ni–Mo/Al2O3 exhibited the highest conversion rate towards 4,6-DMDBT HDS when the amount of Ga2O3 loading was 2 wt.% with an LHSV of 2.5 h−1 at 290°C and Ga modification also can effectively improve the direct desulfurization (DDS) route selectivity in varying degrees.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS COMMUNICATIONS
·
2013
·
IF 2.915
Shuai Leng,Xinde Wang,Xiaobo He,Lin Liu,Yue'e Liu,Xing Zhong,Guilin Zhuang,Jian-guo Wang
NiFe bimetallic catalyst shows an excellent activity and selectivity for the hydrodeoxygenation (HDO) of three typical model compounds of bio-oil. The conversion of furfuryl alcohol, benzene alcohol and ethyl oenanthate is 100, 95.48 and 97.89% at 400 °C and the yield to 2-methylfuran, toluene and heptane is 98.85, 93.49 and 96.11% at 0.1 ml/min flow speed and atmospheric pressure. It indicates that the major reaction pathway is the cleavage of C–O rather than C–C. After the catalytic HDO of bio-oil over NiFe/Al 2 O 3 catalyst, the heating value changes from 37.8 to 43.9 MJ/kg, the pH changes from 6.65 to 7.50.
研究领域:
能源化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
BULLETIN OF MATERIALS SCIENCE
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2020
·Vol. 43
·期 1
·1-7
·
IF 1.392
Xiao Meng,Peng Yu,Pang Mengting,Hao Baicun,Wang Yujia,Zhang Yulian,Liao Yang,Mao Hui
Heterogeneous Pd catalysts were developed by immobilizing Pd nanoparticles (Pd NPs) onto plant polyphenol (bayberry tannin, BT) decorated γ-Al 2 O 3 . The abundant hydroxyls of plant polyphenols were capable of stabilizing the Pd NPs. Transmission electron microscopy observation confirmed that the Pd NPs with the diameter of 3.75 ± 0.5 nm were highly dispersed in the catalyst. The as-prepared Al 2 O 3 –BT–Pd catalysts were found to be highly active in mild hydrodechlorination (HDC) of 2,4-dichlorophenols (DCPs) using formic acid as a hydrogen source. The 2,4-DCPs were completely dechlorinated in 4 h at 30°C and under atmospheric pressure. During the catalytic HDC, the stabilizing capability of BT successfully prevented the leakage and aggregation of Pd NPs, thus ensuring a high cycling stability with stable and high catalytic activity. The Al 2 O 3 –BT–Pd catalysts were recycled six times, without obvious loss of activity. In the sixth cycle, the catalytic HDC yield still reached 98.29% under the same reaction conditions, superior to the control catalysts, including γ-Al 2 O 3 supported Pd NPs (Al 2 O 3 –Pd) and powdered activated carbon supported Pd NPs (AC–Pd). Furthermore, the Al 2 O 3 –BT–Pd also showed high activity in the mild catalytic HDC of 2,4,6-trichlorophenols and chlorobenzene derivatives. Our results demonstrated efficient catalysts to address the environmental issue of chlorophenol pollution.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yihua Qian,Jian Wu,Daofei Lv,Chanchan Xu,Jing Wu,Yaohong Zhao,Qibin Xia
The removal of dibenzyl disulfide (DBDS) from transformer oils is vital to the sustainable operation of transformers. Here, Ag/γ-Al2O3 samples were prepared by a planetary mixer-assisted impregnation method and characterized. The effect of adsorption time and temperature on the equilibrium adsorption of DBDS onto Ag/γ-Al2O3 was discussed. The kinetics and isotherms of DBDS adsorption on the samples were studied. The desorption activation energy of DBDS was also estimated through temperature-programmed desorption (TPD) experiments. Results indicated that the DBDS adsorption capacities on Ag/γ-Al2O3 increased quickly within the first 3 h, and the highest DBDS adsorption capacity was 69.5 mg/g, which was 232, 107, and 5.6 times higher than that of active bentonite, γ-Al2O3, and active carbon, respectively. The adsorption isotherms were well fitted by the Langmuir model, and the adsorption kinetics followed the pseudo-second-order model. The desorption activation energy of DBDS on Ag/γ-Al2O3 was much higher than that on active carbon, indicating a strong interaction between DBDS and Ag/γ-Al2O3. Finally, the hard–soft acid–base (HSAB) principle was used to explain the adsorption mechanism, confirming that DBDS as a soft base can be preferentially adsorbed by Ag/γ-Al2O3 because Ag+ is a soft acid.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Fuming Miao,Shuai Zhang,Xueliang Sun,Yamin Li,Ruize Shang,Wenli Wu,Weizhou Jiao,Youzhi Liu
In this study, Mn-CoO X / γ -Al 2 O 3 (MCA) was prepared by impregnation for catalytic ozonation of phenol in a rotating packed bed (RPB), and the effects of high gravity factor ( β ), liquid flow rate ( Q L ), initial solution pH and gaseous ozone concentration ( C O 3 ) on the mineralization of phenol were explored. The results show that the degradation rate of phenol ( η phenol ) reaches 100% at 9 min and the mineralization rate ( η TOC ) reaches 95.01% at 45 min under conditions of β = 104, C O 3 = 80 mg L -1 , Q L = 80 L/h, and pH = 6. Compared with the bubbling reactor (BR)/MCA/O 3 and O 3 /RPB systems, the η TOC of the MCA/O 3 /RPB system is increased by 25.81% and 40.85%, respectively. The electron paramagnetic resonance (EPR) results reveal that hydroxyl radical (·OH) plays a critical role in the degradation of phenol by MCA catalyzed ozonation. The quenching experiment using tertiary butyl alcohol (TBA) as a scavenger of ·OH reveals that the ratio of direct and indirect degradation of phenol is 16:9. The intermediates generated during the degradation of phenol were detected by gas chromatography-mass spectrometry (GC–MS), and possible degradation pathways were proposed. In conclusion, MCA-catalyzed ozonation and RPB have a synergistic effect on ·OH initiation and improve the degradation and mineralization of phenol. This study provides a new perspective for the degradation of phenol.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Tao Xu,Meihui Jiang,Xuhui Mao,Falak Sher,Tianlin Ren,Kun Xin,Irshad Hussain,Helin Hua,Xu Wang
This study investigated the important role of hydroxyl groups for the preparation of γ-Al 2 O 3 sphere supported metal catalysts. γ-Al 2 O 3 spheres were calcinated at varied temperatures for the analysis of surface hydroxyl group, and they were subsequently loaded with iron to evaluate the metal dispersion and the performance for catalytic ozonation. The results showed that the critical site for metal anchoring was hydroxyl group, thus a higher hydroxyl group content favored the metal dispersion on γ-Al 2 O 3 spheres; meanwhile, the iron-loaded catalysts prepared by the γ-Al 2 O 3 support calcinated at 300 °C achieved the highest catalytic efficiency for p -nitrophenol degradation (74.6 %). The favorable performance of the catalyst was attributed to the excellent dispersion of iron oxide particles, and the abundant oxygen vacancy sites that facilitated the formation of ozone-activating sites, Fe-centered hydroxyl groups ([Fe-OH]). This study provides an important theoretical guidance for the design and application of ozone catalysts.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Qiangqiang Wu,Hanke Li,Guangxing Yang,Yonghai Cao,Hongjuan Wang,Feng Peng,Hao Yu
A variety of adsorbed intermediates have been extensively assigned during CO 2 hydrogenation on Pt/γ-Al 2 O 3 . However, the surface sites where the surface species reside have not been well resolved, which are extremely important to depict the reaction pathways of CO 2 hydrogenation. In the current work, surface species adsorbed on three regions were distinguished by in situ diffuse-reflectance infrared Fourier transform spectroscopy, i.e., contiguous Pt region of Pt nanoparticle, interfacial Pt int -O-Al int region between Pt nanoparticle and γ-Al 2 O 3 , and surface region of γ-Al 2 O 3 away from Pt nanoparticle. The dynamics of adsorbed H species, carbonyl species, bicarbonates, formate species, and adsorbed CO 2 , were identified at different sites, proving that the reaction occurs at the Pt/γ-Al 2 O 3 interface. We found that only the C-containing species at the Pt perimeter are directly active intermediates for the reaction. Such spatial analysis bridges the gap between the hydrogen activation and CO 2 activation, providing a deep understanding of CO 2 hydrogenation. In addition, the interface structure with oxygen vacancy is important for CO 2 activation, driving the reaction through carboxylate (*HOCO) pathway to form CO at the interface rather than formate (*HCOO) pathway and then be hydrogenated at the Pt surface.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Tingwei Zhang,Yongcan Jin,Huining Xiao
Sulfonated carbon/γ-Al 2 O 3 composites (AlSC-x, x = 1, 2, 3) were successfully prepared by the three-step method of impregnation-carbonization-sulfonation. The introduction of sulfonated sucrose-based carbon onto nano-γ-Al 2 O 3 enhanced its Brønsted acidity and weakened the original Lewis acidity. The Brønsted/Lewis acidity of the composite catalysts can be regulated by controlling the sulfonated carbon intake. AlSC-1 containing suitable Brønsted/Lewis acidity showed the best catalytic performance for converting glucose to 5-hydroxymethylfurfural (HMF). In monophasic DMSO/H 2 O (2.0/0.2 mL), an HMF yield of 62.3 % was achieved at 160 °C and 4.0 h when 0.02 g of glucose and 0.02 g of AlSC-1 were used. Adding a moderate amount of water into DMSO is crucial to improve HMF selectivity, and the DMSO/H 2 O system exhibited superior performance to other solvent systems, such as pure water, 1,4-dioxane/H 2 O, and GVL/H 2 O. More importantly, the recyclability of AlSC-1 was pretty good. In addition, AlSC-1 also exhibited much better performance than the other composite catalysts, including sulfonated carbon/nano-TiO 2 , sulfonated carbon/nano-ZrO 2 , and sulfonated carbon/nano-SnO 2 .
研究领域:
化学工程
·
催化科学
✓ 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）