ACS Catalysis
·
2020
·
IF 12.35
Yang Chen,Yingxin Feng,Lin Li,Jingyue Liu,Xiaoli Pan,Wei Liu,Fenfei Wei,Yitao Cui,Botao Qiao,Xiucheng Sun,Xiaoyu Li,Jian Lin,Sen Lin,Xiaodong Wang,Tao Zhang
Exclusive Pt species supported on inert substrates have not achieved satisfactory performance for cryogenic CO oxidation because of the constraint of the competitive Langmuir–Hinshelwood process in which the strongly adsorbed CO inhibits the activation of O2. Here, we develop a catalyst of Pt nanoparticles on Al2O3 that exhibits extremely high activity with 100% CO conversion at −20 °C and orders of magnitude higher specific rate than current commercial catalysts. Detailed catalyst characterizations reveal the presence of metallic Pt sites and positively charged ones associated with the OH species in Pt/Al2O3. Both experimental data and theoretical calculations suggest that CO adsorbed on Pt(OH) kink sites reacts with OH species covering Pt0 terrace sites to release CO2. Afterward, O2 is facilely activated on terrace sites to regenerate OH. The presence of OH species and the synergy between Pt kink and terrace sites on the Pt species lead to an ultralow reaction barrier for CO oxidation.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
VACUUM
·
2020
·
IF 2.906
Hao Sun,Yurong Ren,Zhen Liu,Zhihui Chen,Shuyong Jia
The pristine Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 and Al 2 O 3 -coated Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 with R-3m space group were successfully synthesized by wet chemical method . The TEM shows that the Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 is coated by a dense Al 2 O 3 nano-film with the thickness of 5–10 nm. When used as a cathode material for lithium-ion battery, the Al 2 O 3- coated Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 exhibits much enhanced rate performance and cyclic stability in comparison with those of Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 . It possesses a discharge specific capacity of 245.7, 148.3 and 129.6 mAh g −1 at 0.1, 2 and 4 C, respectively. And 71.4% of its initial discharge capacity is also remained after 50 cycles at the rate of 1 C. The improved electrochemical performance could be the result of the Al 2 O 3 coating on the surface that can avoid the direct contact between the cathode and the electrolyte. It can also stabilize the basic structure of Li 1 · 2 Ni 0 · 13 Co 0 · 13 Mn 0 · 54 O 2 during the delithium/intercalation process.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Hang Qin,Wenming Guo,Hanning Xiao
Sol-gel process was modified by reverse micelles (RMs) for the preparation of γ-Al 2 O 3 ultrafiltration (UF) membranes and their applications in the efficient rejection of methyl blue and bovine serum albumin were explored. The optimized boehmite sol with a narrower particle size distribution and better sphericity was synthesized by using cetyltrimethyl ammonium bromide RMs as microreactors and was dip-coated on α-Al 2 O 3 microfiltration substrates to prepare γ-Al 2 O 3 UF membranes. It was found that not only the sol particle size, it's distribution and morphology had also an important effect on the pore size, pore size distribution , porosity and pore volume of the membrane. Additionally, the as-prepared membranes with a MWCO of 8 kDa exhibited a narrow pore size distribution (4.8–6.8 nm), relatively high pure-water flux (30.4 L/(h m 2 bar)) and excellent rejection for bovine serum albumin and methyl blue with the maximum rejection rate of 96.2% and 96.8% respectively.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2022
·
IF 5.477
Bingying Gao,Chao Yao,Linqiang Mao
Background Advanced aerogels with lightweight, flame retardant and rapid cooling properties are urgently needed as thermal insulators in harsh environments. Method The Cr 2 O 3 −Al 2 O 3 aerogels were fabricated by simple method and freeze-dried process. A large number of pores were produced in the microstructure of samples by carbonization of soluble starch during calcination. Findings The porous structure makes the density of prepared Cr 2 O 3 −Al 2 O 3 aerogel as low as 0.0060 g·cm −3 and the thermal conductivity as high as 0.30 W m −1 ·K −1 , which indicates that the sample has good thermal dissipation and rapid cooling performance. The effect of calcination temperature on cooling rate was studied. The results show that material cooling can be divided into two stages, the second stage is the speed control step. With the increase of the calcination temperature, the cooling rate of sample improves and the cooling time decreases. The prepared Cr 2 O 3 −Al 2 O 3 aerogels have good flame retardancy and cannot ignite upon exposure to the burner for 2 min. The flame retardancy and rapid cooling mechanism of the sample was also studied. The Cr 2 O 3 −Al 2 O 3 aerogels have the advantages of lightweight, flame retardancy and rapid cooling, which has potential application prospects in the field of flame retardant cooling coatings.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
高影响因子
AICHE JOURNAL
·
2018
·Vol. 64
·期 11
·3988-4001
·
IF 3.326
Xiaowen Zhang,Jieling Hong,Helei Liu,Xiao Luo,Wilfred Olson,Paitoon Tontiwachwuthikul,Zhiwu Liang
In this work, the composite catalysts, SO 4 2 /ZrO 2 /γ-Al 2 O 3 (SZA), with different ZrO 2 and γ-Al 2 O 3 mass ratios were prepared and used for the first time for the carbon dioxide (CO 2 )-loaded monoethanolamine (MEA) solvent regeneration process to reduce the heat duty. The regeneration characteristics with five catalysts (three SZA catalysts and two parent catalysts) of a 5 M MEA solution with an initial CO 2 loading of 0.5 mol CO 2 /mol amine at 98°C were investigated in terms of CO 2 desorption performance and compared with those of a blank test. All the catalysts were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, N 2 adsorption–desorption experiment, ammonia temperature programmed desorption, and pyridine-adsorption infrared spectroscopy. The results indicate that the SZA catalysts exhibited superior catalytic activity to the parent catalysts. A possible catalytic mechanism for the CO 2 desorption process over SZA catalyst was proposed. The results reveal that SZA1/1, which possesses the highest joint value of Brφnsted acid sites (BASs) and mesopore surface area (MSA), presented the highest catalytic performance, decreasing the heat duty by 36.9% as compared to the catalyst-free run. The SZA1/1 catalyst shows the best catalytic performance as compared with the reported catalyst for this purpose. Moreover, the SZA catalyst has advantages of low cost, good cyclic stability, easy regeneration and has no effect on the CO 2 absorption performance of MEA. © 2018 American Institute of Chemical Engineers AIChE J , 64: 3988–4001, 2018
研究领域:
化学工程
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催化材料
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环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 19
·10702-10714
·
IF 3.049
Cunlong Li,Yuqing Zhang,Ming Yong,Wei Liu,Jiaqi Wang
In order to effectively clean oily seawater with anionic polyacrylamide (APAM), UiO-66 coated γ-Al2O3 (UA) composites were firstly synthesized using γ-Al2O3 as a template to induce the growth of high hydrophilic UiO-66 on its surface to form a uniform UA self-assembled membrane. The UA composites and self-assembled membrane were characterized and analyzed. Also, the membrane performance was investigated. The results show that the hydrophilicity of particles is enhanced with the water contact angle decreasing from 39.8° (γ-Al2O3 particles) to 26.2° (UA composites) by introducing the UiO-66 coating. Moreover, the UA self-assembled membrane performs attractive water yield and separation performance. The oil concentration in the permeate treated by the first class of UA self-assembled membrane declines apparently from 91.22 to 18.90 mg L−1, while the water yield is as high as 657.89 L m−2 h−1. The reclaimed separation experiments show that the membrane materials could be recycled by calcination at 200 °C and hydraulic cleaning, which gives the material potential application in cleaning oily seawater.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 11
·15709-15721
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IF 4.672
Qiuwan Shen,Zicheng Shao,Zhongwen Cai,Min Yan,Guogang Yang,Shian Li
Summary Methanol steam reforming (MSR) is a promising method for hydrogen production from renewable energy. The effect of λ-Al 2 O 3 support derived from metal-organic frameworks (MOFs) aluminum fumarate (A520) on the performance and stability of LaNi 0.4 Al 0.6 O 3-δ for MSR is investigated. Results demonstrate that compared with LaNi 0.4 Al 0.6 O 3-δ , LaNi 0.4 Al 0.6 O 3-δ /λ-Al 2 O 3 can achieve complete conversion of methanol and excellent thermal stability due to the higher S BET and strong interaction between the metal components and λ-Al 2 O 3 . Characterization results indicate that the LaNi 0.4 Al 0.6 O 3-δ /λ-Al 2 O 3 catalyst, which was not successfully reduced due to its robust structure, still has active sites for the MSR reaction. This characteristic of the catalyst has the potential to be applied for onboard in-situ hydrogen production, because it can shorten the time of hydrogen reduction process. Furthermore, the effects of catalytic temperature, feed water-methanol ratio, and liquid hourly space velocity on performance of LaNi 0.4 Al 0.6 O 3-δ /λ-Al 2 O 3 are studied in detail and the optimal conditions are determined and applied for stability tests.
研究领域:
材料科学
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催化化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2018
·Vol. 15
·期 5
·1146-1156
·
IF 1.165
Qingliang Shan,Jianbao Hu,Yanmei Kan,Dewei Ni,Le Gao,Xiaowu Chen,Shaoming Dong
Si-B-C ceramics were prepared through reaction sintering, and the influence of Al 2 O 3 addition on the high-temperature (1100-1300°C) oxidation behavior of the material under air atmosphere was studied. The erosion behavior and mechanism are determined from the measurement of weigh changes, microstructure observations, and characterization of the generated oxides on postexposure specimens. Results show that Al 2 O 3 is enriched in the oxidized layer, inhibiting the volatilization of B 2 O 3 and impeding the crystallization ability of oxide (cristobalite). Narrower erosion layer and less weigh change are observed with Al 2 O 3 . Low-frequency Raman results reveals that with the increase in Al 2 O 3 , the bending vibrations of the BO 4 units and B-O-B stretching of the metaborate ring relative intensity are enhanced. Furthermore, high-frequency Raman results shows that the relative proportion of high-dimensional vibration modes Q 3 and Q 4 which result in a higher viscosity of melt and a greater resistance of oxygen diffusion are positively correlated with Al 2 O 3 .
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2017
·
IF 4.208
Hongyun Hu,Dunkui Chen,Huan Liu,Yuhan Yang,Hexun Cai,Junhao Shen,Hong Yao
Arsenic emission from fuel combustion and metal smelting flue gas causes serious pollution. Addition of sorbents is a promising way for the arsenic capture from high temperature flue gas. However, it is difficult to remove arsenic from SO 2 /HCl-rich flue gas due to the competitive reaction of the sorbents with arsenic and these acid gases. To solve this problem, arsenic adsorption over γ-Al 2 O 3 was studied in this work to evaluate its adsorption mechanism, resistance to acid gases as well as regeneration behavior. The results show that γ-Al 2 O 3 had good resistance to acid gases and the arsenic adsorption by γ-Al 2 O 3 could be effectively carried out at a wide temperature range between 573 and 1023 K. Nevertheless, adsorption at higher-temperature (like 1173 K) leaded to the decrease of surface area and the rearrangement of crystal structure of γ-Al 2 O 3 , reducing the active sites for arsenic adsorption. The adsorption of arsenic was confirmed to occur at different active sites in γ-Al 2 O 3 by forming various adsorbed species. Increasing temperature facilitated arsenic transformation into more stable chemisorbed As 3+ and As 5+ which were difficult to remove through thermal treatment regeneration. Fortunately, the regeneration of spent γ-Al 2 O 3 could be well performed using NaOH solution.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Jiayu Feng,Ping Ning,Kai Li,Xin Sun,Chi Wang,Lijuan Jia,Maohong Fan
The conventional Haber–Bosch NH3 synthesis process requires high temperatures and pressures, resulting in a high carbon footprint and the need to develop alternative NH3 synthesis methods. Accordingly, plasma-based and γ-Al2O3-catalyzed NH3 synthesis from H2O (a hydrogen source) and air/N2 (a nitrogen source) was studied under low temperature and low pressure conditions. The experimental results show that NH3 can be synthesized with air/N2 and H2O, although byproducts such as NO and N2O are also formed. The NH3 formation rate resulting from the use of N2 and H2O is higher than that of air and H2O. Increasing specific energy input (SEI) can increase the NH3 formation rate. Nevertheless, the energy efficiency of NH3 synthesis technology first increases and then decreases with SEI. An NH3 formation rate of 2.92 μmol h–1 g–1 was achieved with an SEI of 11.68 J mL–1 and energy efficiency of 5.10 mg kW–1 h–1 (1.28 mg kWh–1g–1), when wet air at a flow rate of 200 mL min–1 was introduced into the dielectric barrier discharge (DBD) reactor, which was lower than that (4.30 μmol h–1 g–1) attained with N2 + H2O under an SEI of 11.50 J mL–1 and energy efficiency of 7.63 mg kW–1 h–1 (1.91 mg kWh–1g–1). Additionally, the γ-Al2O3 catalyst exhibited good stability. Different results show that plasma-based and γ-Al2O3 catalyzed NH3 synthesis technology is promising.
研究领域:
化学工程
·
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2023
·Vol. 15
·期 7
·e202300194
·
IF 4.5
Tao Li,Mengling Dong,Jiacheng Xu,Tiantian Zhang,Yan Sun,Ning Li,Zuliang Wu,Jing Li,Erhao Gao,Jiali Zhu,Shuiliang Yao,Yong Huang
Graphical CeO 2 /γ-Al 2 O 3 , Pd/CeO 2 , and Pd/CeO 2 /γ-Al 2 O 3 were used for catalyzing low-concentration CH 4 oxidation . γ-Al 2 O 3 can efficiently promote CH 4 oxidation on Pd/CeO 2 and the formation of bicarbonate that is easily gasified to CO 2 . CeO 2 /γ-Al 2 O 3 , Pd/CeO 2 , and Pd/CeO 2 /γ-Al 2 O 3 were used for catalyzing low-concentration CH 4 oxidation. It was found that nano-sized Pd could obviously promote CH 4 oxidation on CeO 2 /γ-Al 2 O 3 . The interaction between Pd and CeO 2 on γ-Al 2 O 3 resulted in higher ratios of Ce 3+ /(Ce 3+ +Ce 4+ ), Pd 2+ /(Pd 2+ +Pd δ+ ), and O ads /(O ads +O latt ), those benefited the formation of more oxygen vacancies and surface reactive oxygen species for CH 4 oxidation. γ-Al 2 O 3 not only supplied a high surface area and enhanced Pd/CeO 2 dispersion on γ-Al 2 O 3 , but also simulated the formation of bicarbonate, where bicarbonate is easier to gasify to CO 2 than bidentate carbonate that formed on Pd/CeO 2 . Operando diffuse reflectance infrared Fourier transform spectroscopy-mass spectrometer analysis results showed that CH 4 oxidation could occur at a temperature as low as 180 °C due to the reaction with surface reactive OH, this reaction was also accompanied by the formation of bicarbonate. The mechanism of CH 4 oxidation promoted by bicarbonate formation on γ-Al 2 O 3 was proposed.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic and Nano-Metal Chemistry
·
2017
·
IF 0
Caina Li,Zhihua Zhao,Yukun Liu,Dongxia He,Xiaoqing Shen
Al2O3-SiO2 composite nanofibers were fabricated by calcining the precursor fibers obtained through sol–gel processing and electrospinning technique. Thermogravity-differential scanning calorimeter, powder X-ray diffraction, X-ray fluorescence analysis, scanning electron microscopy, transmission electron microscopy, and thermal conductivity instrument were employed to characterize the fibers. Upon calcining the precursor fibers at 1300°C, continuous Al2O3-SiO2 composite nanofibers with diameter of about 300 nm can be obtained. The calcined fibers had low thermal conductivity, which might favor their application in high-temperature insulation areas.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
危险品化学品经营许可证（带存储）