FUEL
·
2024
·
IF 6.7
Shaoliang Zhu,Bingtao Zhao,Yaxin Su
High-efficiency and cost-effective adsorbents are crucial to dry capture of carbon dioxide (CO 2 ). The polyethyleneimine (PEI) was co-impregnated with tetraethylenepentamine (TEPA) on γ-alumina (Al 2 O 3 ) to synthesize the adsorbent and enhance the capture process. The influence of amine loading and operating parameters on CO 2 adsorption was investigated, and the process parameters were modeled. The results depict that the optimal loading is 50 % when functionalized either PEI or TEPA individually, which is 3.7 and 4.6 times higher than γ–Al 2 O 3 . The CO 2 capacity of γ–Al 2 O 3 functionalized with multiple amines (30 %PEI+20 %TEPA) is 2.65 mmol/g, due to the synergies of the two amines to increase the chance of CO 2 binding to the sites. Regeneration performance illustrates that the adsorbent remains at 90.2 % of the initial capacity after seven tests. The maximal capacity of 2.70 mmol/g occurs at 70 °C. Modeling results indicate the kinetics can be evaluated by the Avrami model (R 2 > 0.990) with the activation energy of 5.65 kJ/mol. The process is controlled by physical–chemical adsorption, influenced by intraparticle diffusion, as described by the deactivation model. Finally, a comparison and assessment were conducted for their techno-economic performances, and the pathway to applications was also proposed in engineering practice.
研究领域:
化学工程
·
环境科学
✓ 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
FUEL
·
2019
·
IF 5.128
Xue-Ke Li,Zhi-Min Zong,Yi-Feng Chen,Zheng Yang,Guang-Hui Liu,Fang-Jing Liu,Xian-Yong Wei,Bao-Jun Wang,Feng-Yun Ma,Jing-Mei Liu
A highly active difunctional Ni-Mg 2 Si/γ-Al 2 O 3 was prepared by thermally decomposing nickel tetracarbonyl onto γ-Al 2 O 3 impregnated with Mg 2 Si. The non-catalytic hydroconversion (NCHC) and catalytic hydroconversion (CHC) of the extract ( E ) and extraction residue (ER) from Yinggemajianfeng lignite were investigated over Ni-Mg 2 Si/γ-Al 2 O 3 at 240 °C in n -hexane. Benzyloxybenzene and oxybis(methylene)dibenzene were used as lignite-related model compounds to speculate the possible mechanisms for the catalytic hydrocracking and hydrogenation over Ni-Mg 2 Si/γ-Al 2 O 3 . As a result, more organic matter in ER was converted to soluble portion (SP) by the CHC than by the NCHC. The main SP from the CHC are chain alkanes and cyclanes, while that from the NCHC is rich in arenes and oxygen-containing organic compounds. The results indicate that Ni-Mg 2 Si/γ-Al 2 O 3 effectively catalyze the hydrocracking of >C alk –O– linkages and the hydrogenation of aromatic rings in E and ER.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xinyu Yang,Zezhi Chen,Huijuan Gong,Feng Lin,Tingting Zhu,Ziyi Yang
Deoxygen is a crucial step for landfill gas (LFG) recycling and purification. Pt/γ-Al 2 O 3 is the most active catalyst for LFG deoxygen via catalytic methane oxidation . It is challenging but significant to further improve the performance of this type of catalyst. In regard of homogeneous and heterogeneous activation of methane by superacids , here we demonstrate LFG deoxygen via catalytic methane oxidation using a solid superacid catalyst, Pt/SO 4 2- /Al 2 O 3 , synthesized using pre-sulfated γ-Al 2 O 3 support by impregnated with sulfuric acid . In comparison to Pt/γ-Al 2 O 3 , Pt/SO 4 2- /Al 2 O 3 catalysts exhibit exceptionally improved activity and minimum complete O 2 conversion at a temperature of 264 ℃, a decrease of about 51 ℃. This value is superior to the state-of-the-art Pt-based deoxygen catalysts. Characterizations and theoretical calculations indicate that sulfation enhances the amount of acid sites on γ-Al 2 O 3 support and induces electron deficiency of the supported Pt species (+0.28|e|), thus boosting the low-temperature activity. Furthermore, the Pt/SO 4 2- /Al 2 O 3 catalyst maintained its initial activity after six runs without any detectable coke deposition. This discovery offers simple and effective strategies to precisely design higher performance application-oriented Pt based deoxygen catalysts.
研究领域:
催化
·
环境工程
·
材料科学
✓ 已验证
产品关联
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
·
催化材料
·
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
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 56
·84166-84179
·
IF 5.19
Gao Panting,Li Yuran,Lin Yuting,Chang Liping,Zhu Tingyu
Catalytic hydrolysis of carbonyl sulfur (COS) from blast furnace gas is one of the keys to achieving ultra-low emission in the iron–steel industry. To improve the COS hydrolysis activity on γ-Al 2 O 3 catalyst at low temperature, catalysts with Fe or La as the active component were prepared by the impregnation method, the physical and chemical properties of the catalyst were characterized by ICP, XRF, XRD, BET, and TPD. The hydrolysis activity of COS and sulfur resistance ability on various catalysts were investigated in a fixed bed reactor combined with gas chromatography. The results show that the addition of Fe or La improves the COS hydrolysis activity due to the increase in alkaline sites on the catalyst surface. The roles of various alkaline sites on catalysts have been recognized. The weak alkaline center is the reaction site of COS hydrolysis, the middle and strong alkaline centers are the adsorption and oxidation sites of H 2 S. The Fe/Al 2 O 3 catalyst has higher hydrolytic activity and oxidative capacity for H 2 S removal due to forming more sulfate species on Fe. The La/Al 2 O 3 catalyst has higher hydrolysis efficiency in that H 2 S rapidly desorbs from the catalyst surface to the gas phase, and then, the activity of reaction sites is recovered. This provides an idea for the preparation of sulfur-resistant catalysts.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2014
·
IF 5.211
Xiaoyan Liu,Zhongqiang Shan,Kunlei Zhu,Jiangyong Du,Qiwei Tang,Jianhua Tian
Lithium sulfur batteries have brought significant advancement to the current state-of-art battery technologies due to their high theoretical specific energy of 1675 mAh g −1 . However, the rapid capacity degradation, mainly caused by polysulfide dissolution, remains a significant challenge prior to practical applications. In this work, a sulfur cathode modified by bifunctional nafion/γ-Al 2 O 3 membrane has been successfully prepared, which can remarkably immobilize the polysulfides within the unique cathode structure due to its ions selectivity and absorbent capacity. A high initial discharge capacity of 1448.0 mAh g −1 can be achieved at 1C and 788.6 mAh g −1 preserved after 200 cycles, indicating a slow degradation. Furthermore, the coulombic efficiency maintains as high as 97% during cycling. The excellent electrochemical properties can be attributed to the bifunctional and stable membrane which can dramatically reduce the shuttle effect and keep integrated even after charging–discharging for 200 cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
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
·
生物质转化
·
材料科学
✓ 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）