JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Chenyuan Guo,Shuguang Shen,Meina Li,Ying Wang,Jing Li,Yuanquan Xing,Cui Wang,Huajie Pan
A rapid and efficient synthesis strategy of MgAl-LDH was proposed. MgAl-LDH with high specific surface area was synthesized in situ by using η -Al 2 O 3 as carrier, and the synthesis time was greatly shortened by both increasing temperature and introducing ethanol as co-solvent. Besides, the growth process of MgAl-LDH on the surface of η -Al 2 O 3 is also revealed. Under optimized conditions, the specific surface area of the MgAl-LDH is as high as 172.4 m 2 /g, the crystalline size is as small as 12.82 nm, and the basicity can reach 1.795 mmol/g. The urea wastewater was degraded from 8000 mg/L to 6.85 mg/L over the catalyst synthesized by the rapid method, and the catalyst still maintains high activity after four uses. Also, it was found that there is a good linear relationship between the urea removal rate and the basicity of MgAl-LDH.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Xiaojing Xi,Juan Li,Huajun Chen,Rui Wang
In this work, we prepared mesoporous η-Al 2 O 3 nanofiber with tunable pore size using diverse surfactants . The as-prepared mesoporous η-Al 2 O 3 nanofiber was characterized by a combination of various physicochemical techniques. The influence of surfactants types and polymerization degree on surface morphology and adsorption performance of mesoporous η-Al 2 O 3 nanofiber was compared. The results of transmission electron microscopy (TEM), low-angle X-ray diffraction (XRD) and N 2 adsorption–desorption isotherm prove the existence of mesoporous structure in η-Al 2 O 3 nanofiber. Polyethylene glycol (PEG) is favored over polyether (PPG) in the preparation of mesoporous η-Al 2 O 3 nanofiber, and PEG with a lower degree of polymerization is beneficial to form well-defined mesoporous structure. The η-Al 2 O 3 nanofiber (PEG600) has the highest specific surface area and the best adsorption performance, followed by the η-Al 2 O 3 nanofiber (PEG2000), and then the η-Al 2 O 3 nanofiber (PPG). Both the adsorption isotherm and the adsorption kinetics equation prove that the adsorption mechanism of methylene blue on mesoporous η-Al 2 O 3 nanofiber is the combination of chemical and multilayer adsorption. This work provides a new avenue to prepare mesoporous η-Al 2 O 3 nanofiber with tunable pore size for the application of mesoporous material in battery, adsorbent, catalytic and biomedical carrier.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Zhichao Yang,Weiquan Cai,Jinpeng Zhou,Qing Xia,Tielin Wang
A fast, large-scale, and stable preparation method was successfully developed to obtain η-Al2O3 microspheres with particle sizes of 3–10 μm from cheap and widely sourced NaAlO2 solution using N,N-dimethylformamide (DMF) as a morphological modifier and a precipitant simultaneously at room temperature. The yield of alumina increases from 33.3 to 77.3% by increasing the dose of DMF from 100 to 400 mL. The utilization efficiency of DMF significantly increased by adding fresh NaAlO2 into the reused filtrate after separating the bayerite precipitate (precursor of η-Al2O3). Importantly, the η-Al2O3 microspheres obtained from the filtrate-reuse experiments show the stable phase structures, morphologies, and pore structure properties. Furthermore, the typical η-Al2O3 microspheres supported Pd catalyst presents a higher catalytic activity of 10.6 g/L for the hydrogenation of anthraquinone than that of the commercial γ-Al2O3-supported Pd catalyst (8.5 g/L), suggesting that the as-prepared η-Al2O3 microspheres have good application prospects for catalytic hydrogenation and related fields.
研究领域:
材料科学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2015
·
IF 1.173
Shuguang Shen,Binbin Li,Meina Li,Jimin Fan,Zhijun Zhao
In order to find an effective method for urea removal from wastewater, a number of experiments were conducted in a batch reactor with α-Al2O3 and η-Al2O3 as catalysts, respectively. The results indicate that η-Al2O3 catalyst shows significantly higher urea removal rate than α-Al2O3 catalyst or the thermal hydrolysis, and the removal rate increases with increasing temperature, catalyst dosage and reaction time. Using η-Al2O3 catalyst, the urea concentration in wastewater is reduced to less than 1 mg/L at 165°C after 150 min. The reaction kinetics study shows that the hydrolysis of urea behaves as a pseudo-first-order reaction. From the calculated rate constants, η-Al2O3 exhibits an excellent catalytic activity for urea hydrolysis, whereas the activity of α-Al2O3 is considerably weak. In addition, the η-Al2O3 catalyst possesses good recycling ability. The slight loss of activity of η-Al2O3 should be attributed to the generation of a small amount of hydrated aluminas, and the activity can be recovered by calcination.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 21
·12563-12568
·
IF 2.757
Shen Shuguang,Li Meina,Li Binbin,Zhao Zhijun
In order to find an effective method for treating urea wastewater, the experiments on the hydrolysis of urea in wastewater were conducted in a fixed bed reactor with different aluminas (α-Al 2 O 3 , γ-Al 2 O 3 , and η-Al 2 O 3 ) as catalysts respectively in contrast with inert ceramic particle. The results indicate that the three alumina catalysts show obvious catalytic activity for urea hydrolysis at 125 °C. The order of activity is η-Al 2 O 3 > γ-Al 2 O 3 > α-Al 2 O 3 , and the activity difference increases with increasing temperature. According to the characterization results, surface acidity has little impact on the activity of catalyst. However, it was found that surface basicity of alumina catalyst plays an important role in catalytic hydrolysis of urea, and the activity of catalyst may be also influenced by the basic strength. With η-Al 2 O 3 as catalyst, the urea concentration in wastewater is reduced to 4.96 mg/L at a temperature of 165 °C. Moreover, the η-Al 2 O 3 shows a good stability for urea hydrolysis. The hydrolysis of urea over η-Al 2 O 3 catalyst can evidently reduce the reaction temperature and is promising to replace industrial thermal hydrolysis process.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2025
·
IF 2.6
Zhihui Li,Xinfa Dong
Among the various methods for removing carbon monoxide (CO) from hydrogen-rich (H2-rich) gases, carbon monoxide selective methanation (CO-SMET) has become one of the most effective ones, bringing considerable advantages in terms of performance, environmental sustainability and cost. A bimetallic NiRu/η-Al2O3 catalyst with Ni–Ru alloy phases was prepared and its performance in the removal of CO through a selective methanation process was examined in this study. Also, a comparison was made with the NiRu/γ-Al2O3 catalyst. The NiRu/η-Al2O3 catalyst demonstrated excellent CO-SMET performance, reducing the CO concentration to below 10 ppm with over 50% selectivity between 215 and 300 °C. Its excellent catalytic performance can be ascribed to numerous Ni active sites, increased oxygen vacancies, and more acidic sites. Additionally, the NiRu/η-Al2O3 catalyst had the ability to resist sintering because of the formation of Ni–Ru alloy on it. Moreover, it also exhibited good catalytic stability.
研究领域:
催化化学
·
能源材料
·
环境催化
·
化学工程
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 7
·1893-1903
·
IF 2.911
Wang Ying,Shen Shuguang,Li Meina,Sun Yujuan,Li Binbin
Abstract Magnesium aluminum layered double hydroxide (MgAl–LDH) was first successfully deposited in situ on η -Al 2 O 3 applied to catalyze urea hydrolysis. Characterization by AAS, XRD, SEM, EDS, DSC, FT-IR, N 2 -BET, determination of base strength and basicity and experiments on hydrolysis activities of in situ MgAl–LDH catalysts show that the crystallinity and coverage degree of MgAl–LDH on η -Al 2 O 3 gradually increase with increasing initial c (Mg 2+ ). When initial c (Mg 2+ ) = 2 mol L −1 , η -Al 2 O 3 is completely covered and the smallest particle size, the highest crystallinity, basicity and urea degradation rate of in situ MgAl–LDH are obtained. The basicity is mainly from Mg–OH at the edges of MgAl–LDH on η -Al 2 O 3 . The highest basicity corresponds to the highest urea degradation rate, Mg–OH is the active sites for catalytic hydrolysis of urea. The specific surface area, basicity and catalytic activity of MgAl–LDH by in situ synthesis are evidently higher than MgO and MgAl–LDH purchased. The urea concentration is 8.162 mg L −1 at 165 °C after 120 min with in situ MgAl–LDH ( c (Mg 2+ ) = 2 mol L −1 ) as catalyst, which is below the effluent standard. In situ MgAl–LDH also shows excellent recycling ability and the slight loss of activity should be due to the reduction of basicity, which is caused by hydrothermal conditions. In addition, a possible catalytic mechanism of urea hydrolysis over MgAl–LDH is proposed. Graphical Abstract
✓ 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）