POWDER TECHNOLOGY
·
2023
·
IF 5.2
Yuxiang Cheng,Zhongjie Shen,Feng Lv,Dayang Wan,Yongchuan Gao,Yiru Yang,Haifeng Lu,Zhenghua Dai,Haifeng Liu
During the Ca(OH) 2 /CaO thermochemical energy storage process, the cyclability of reactions and the consolidation properties of powder storage are important issues to consider. In this study, experiments were conducted to assess the evolution of reaction conversion, particle size and penetration resistance of Ca(OH) 2 /CaO powder fixed bed. The results revealed that the final conversions of both the hydration and dehydration reactions stabilized between 70 and 80%. The particle size distributions of Ca(OH) 2 increased initially and then decreased with the increasing cycle number and degree of dehydration. The dehydration conversion was the dominant factor for changing Ca(OH) 2 bed penetration resistance force. The particle size and penetration resistance of the CaO bed remained stable during long-term storage at high temperatures. The theoretical analysis of the inter-particle forces agreed with the trend of the experimental results, with particle size and moisture content being the main factors affecting cohesion.
研究领域:
材料科学
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能源工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Chenyu Yang,Qian Yao,Liangzhong Li,Xian Xiao,Lun Lu,Chang Liu,Chunyou Zhu,Sihui Zhan,Haoran Yuan
The biochar with single Ca atom (1.7 wt%) loaded nanoscale zero-valent iron composites (Fe@Ca-N-C) were prepared and effectively degraded tris(2-chloroethyl) phosphate (TCEP) via Fenton-like oxidation. Systematic experiments and theoretical calculations indicated that the enhanced removal of TCEP was attributed to the synergistic effect of adsorption (Ca-N x sites) and degradation (Fe sites). Remarkably, the optimal system of 0.1 g L −1 Fe@Ca-N-C, 1 mM peroxydisulfate (PDS) achieved 99.5 % TCEP degradation (2 mg L −1 ) in 30 min and maintained 100 % TCEP removal for 72 h in continuous-flow reaction column. The Ca-N x sites exhibited high adsorption energy for TCEP (especially the Ca-N 1 sites), and the Fe sites (Fe(0) and Fe(Ⅱ)) activated PDS into HO•, which quickly degrades the adsorbed TCEP through C-O bond breaking and C-Cl bond hydroxylation. This study provided insights into single Ca atom utilization and TCEP pollution remediation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 17
·5829-5839
·
IF 5.721
Hanlin Chen,Gaoling Wei,Xiaoliang Liang,Peng Liu,Yunfei Xi,Jianxi Zhu
Thermal catalytic oxidation is regarded as an effective technique to eliminate volatile organic compounds (VOCs), whereby perovskite-type oxides have been reported as low-cost and highly efficient transition metal catalysts. In this study, we employ two facile modification methods, i.e., Ca substitution and citric acid etching, to further improve the catalytic activity of LaCoO3 perovskite for toluene oxidation. The Ca-substituted LaCoO3 (La0.9Ca0.1CoO3) and citric acid-etched LaCoO3 (LaCoO3–CA) show T90 values at 220 and 215 °C, respectively, which are substantially lower than that of pristine LaCoO3 (305 °C). When LaCoO3 is modified by both Ca substitution and citric acid etching, i.e., La0.9Ca0.1CoO3–CA, the T90 further decreases to 202 °C, even lower than that of the commercial catalyst 0.5 wt% Pt/Al2O3 (208 °C). In terms of specific reaction rate at 200 °C, the activity of the above catalysts is also enhanced as follows: LaCoO3 (0.14 μmol s−1 m−2) < La0.9Ca0.1CoO3 (0.31 μmol s−1 m−2) < LaCoO3–CA (0.47 μmol s−1 m−2) < La0.9Ca0.1CoO3–CA (0.63 μmol s−1 m−2). The effects of Ca substitution and citric acid etching are discussed in light of the crystal structure, morphology, and lattice defects. On the one hand, Ca substitution and citric acid etching increase the specific surface area and pore volume, which facilitate the contact between toluene and active sites. On the other hand, these methods produce more oxygen vacancies, enhance the reducibility, and facilitate the adsorption of oxygen. The above merits result in the increase in the specific reaction rate. The modified catalysts show a better water resistance than pristine LaCoO3. As verified in the H2O-TPD characterization, this phenomenon is ascribed to the generation of surface hydroxyl groups, which are beneficial for toluene oxidation at high humidity.
研究领域:
环境科学
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催化材料
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
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IF 2.7
Jiajie Xue,Lingjun Kong,Wei Lin,Jiasheng Zhang,Youzhi Zhu
The development of sensitive breast cancer biomarker (CA 15-3) measurement techniques is of great significance for the early diagnosis and therapeutic monitoring of breast cancer worldwide. Herein, we have designed a split-type photoelectrochemical (PEC) immunoassay platform for the ultrasensitive determination of CA 15-3 using In2O3/ZnIn2S4 heterojunctions with high photovoltaic conversion performance as a photoactive substrate. Efficient photocurrent-responsive In2O3/ZnIn2S4 was formed by surface loading narrow-bandgap ZnIn2S4 on MOF-derived wide bandgap In2O3 nanomaterials. Subsequently, a sandwich immunoreaction was performed using an alkaline phosphatase (ALP)-labeled secondary antibody as a signaling indicator to produce large amounts of ascorbic acid by enzymatic biocatalysis. Since ascorbic acid is an excellent electron donor capable of promoting photogenerated electron separation in semiconductor materials, it enhances the anodic photocurrent of In2O3/ZnIn2S4-modified electrodes. Under the optimal catalyst loading and immunoreaction time, the In2O3/ZnIn2S4-based PEC immunoassay showed a good photocurrent response to CA 15-3 over a wide detection range from 1.0 mU mL−1 to 10 000 mU mL−1 with a limit of detection of 0.45 mU mL−1. Owing to the excellent photocurrent response of In2O3/ZnIn2S4 to ascorbic acid and the split-type immunoassay protocol, the constructed PEC immunosensing platform has the advantages of high precision, anti-interference, and acceptable accuracy, and the results are equivalent to those of commercial enzyme-linked immunosorbent assay (ELISA) kits.
研究领域:
生物医学工程
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肿瘤学
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分析化学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2018
·Vol. 36
·期 9
·1027-1035
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IF 2.016
Shen Xiao-Long,Wang Zi-Qing,Wang Qing-Yin,Liu Shao-Ying,Wang Gong-Ying
Ca/SBA-15 solid bases with different Ca/Si atomic ratios were prepared by a one-pot route and employed as catalysts for the production of poly(isosorbide carbonate) (PIC) from diphenyl carbonate and isosorbide via a transesterification polymerization process. The relationship between physicochemical properties and catalytic performance for Ca/SBA-15 in this melt process was investigated by means of various characterization techniques. It was found that basic site amount and strength were responsible for this transesterification process; the weak and medium basic sites inclined to promote polycondensation reaction. It was worth noting that strong basic sites could favor the decomposition of the resultant PIC, resulting in the decrease of weight-average molecular weight ( M w ) and yield, and the sample with Ca/Si atomic ratio of 0.4 exhibited the best catalytic performance, giving PIC with M w of 4.88 × 10 4 g/mol and T g of 169 °C at the optimal conditions. This excellent activity can be ascribed to the presence of rich basic sites and specific basic strength on the surface of 0.4Ca/SBA-15.
研究领域:
材料科学
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聚合物化学
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催化
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产品关联
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 7
·685
·
IF 4.501
Hao Dong,Cheng-Hua Xu,Fang-Lu Yang,Lei Du,Chen-Long Liu,Wen-Jing Chen,Lin Wang
Ca–Zr–Sn composite oxides catalysts for 1,4-butanediol (BDO) selective dehydration to 3-butene-1-ol (BTO) are synthesized by impregnation and co-precipitation in the present work. The results show that Ca–Zr–Sn catalysts prepared from co-precipitation by using NaOH-Na2CO3mixing alkali solution as precipitant exhibit an excellent catalytic property for BDO dehydration to BTO. For instance, Ca–Zr–Sn oxide with Ca/Zr and Sn/Zr molar ratio of 0.68 and 0.28 calcined at 650 °C gives a BDO conversion and BTO selectivity of about 97% and 82%, respectively, and exhibits no deactivation during 1000 h scale-up experimental testing. X-ray diffraction results indicate that catalytic active centers for BDO dehydration to BTO are from Ca0.15Zr0.85O crystal phase. NH3- and CO2-temperature programmed desorption prove that the surface of obtained catalysts can provide a large amount of acid and base sites simultaneously. FT-IR spectra of pyridine-adsorbed samples show that acid sites on the surface of Ca–Zr–Sn oxide catalyst mainly exist in a state of Lewis acid, which activates terminal -OH groups of BDO molecule through complexing. The activated -OH interacts with β-H activated on base sites O2−anions relative to Ca species, thereby the CH2=CH- bonds are produced through dehydration to form BTO.
研究领域:
化学工程
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催化材料科学
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DOI
高影响因子
DESALINATION
·
2022
·
IF 11.211
Yaxu Guan,Shao-Lu Li,Zhenxing Fu,Yiwen Qin,Juntao Wang,Genghao Gong,Yunxia Hu
In this work, we synthesized a zwitterionic polymer PEI-CA for the first time and then grafted it onto the surface of polyamide RO membrane via layer-by-layer interfacial polymerization (LbL-IP). XPS and ATR-FTIR techniques were used to verify the successful modification with PEI-CA. The zwitterionic hyperbranched polymer PEI-CA endowed the modified membrane with much improved surface hydrophilicity and decreased surface negative charge. The tailored M-PEICA exhibited a high water permeance up to 3.92 L m −2 h −1 bar −1 (increased by 62 %) while holding a good NaCl rejection (98.93 %). The dynamic fouling experiments proved that grafting of PEI-CA can help to effectively elevate its antifouling performance against most organic foulants except small molecular negatively charged surfactant SDS. Therefore, we further employed the mixed reagents modification strategy with arginine and PEI-CA, the resulting RO membrane M-mixed presented obviously improved antifouling performance towards SDS, the overall antifouling performances are even better than the well-known RO membrane CR100 of DOW FILMTEC™, that well illustrated multiple reagents modification strategy could be an efficient way that can meet all critical standards. Overall, the novel polymer PEI-CA and as-fabricated RO membranes with outstanding antifouling performances in this study have vast application potential in field of water treatment .
研究领域:
水处理
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膜科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
De-hua Wang,He-bin Li,Hong-wei He,Yang Deng,Ye Lu,Le Zhang,Ke-qing Ruan,Xiao-xiong Wang
Piezoelectric catalysis has become an emerging research field in recent years, which has received extensive attention. Nanoparticles and nanowires have been developed as piezoelectric catalytic materials. However, in practical research, the use of nanoparticles is not easy for the recovery of samples and will cause secondary pollution, and the current piezoelectric catalysis requires the help of high-frequency ultrasound, which increases the consumption of extra energy and cannot be applied on a large scale. In this study, a self-supporting macroscopic flexible inorganic (Ba,Ca)TiO3:Pr nanofiber membrane was successfully prepared by electrospinning. Natural energy (water flushing) was used to drive the flexible inorganic (Ba,Ca)TiO3:Pr nanofiber membrane for piezoelectric catalytic degradation of organic dyes. The results show that the flexible inorganic (Ba,Ca)TiO3:Pr nanofiber membrane driven by water washing has an obvious piezoelectric catalytic degradation effect on dyes. When the water flow rate was 450 L/h and the concentration of CR solution was 10 mg/L, the catalytic efficiency can reach 91.69%. This study provides a green and feasible method for the preparation of flexible inorganic piezoelectric catalytic materials and the catalytic degradation of organic dyes.
研究领域:
材料科学
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环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Ayesha Idrees,Ali Shan,Waqas Qamar Zaman,Ali Mohsin,Zain Abbas,Tanvir Shahzad,Atif Shakeel,Shuguang Lyu
M-metal (Ca and Cu) doped Ca-Fe 2 O 3 and Cu-Fe 2 O 3 catalysts were synthesized using solvothermal method. The Ca-Fe 2 O 3 and Cu-Fe 2 O 3 catalysts were characterized by XRD, Raman spectroscopy , SEM , TEM and XPS spectroscopy. The catalytic performance of 6%Ca-Fe 2 O 3 and 5%Cu-Fe 2 O 3 catalysts for trichloroethylene (TCE) removal were improved by M-metal doping leading to TCE removal at 99.8% in 1 h, which were three folds greater than by simple a- Fe 2 O 3 in the presence of persulfate (PS). Ca and Cu doping formed defective structure and created more oxygen vacancies thereby generating abundant active species during PS activation process. Further, the influence of catalysts’ dosage, oxidant dosage, solution pH, inorganic anions, and dissolved oxygen were evaluated. Complete removal of TCE was also obtained at weak alkaline pH condition. The greater specific surface area and the improved electrical conductivity was attributed to the huge generation of O 2 •– and 1 O 2 species which played major part in TCE removal. Scavenging tests and ESR spectroscopy confirmed the dominant role of O 2 •– and 1 O 2 in TCE degradation. The stability and viability of 6%Ca-Fe 2 O 3 and 5%Cu-Fe 2 O 3 catalysts were evaluated by repetition tests and in the presence of surfactants, TCE removal in real water matrix, and in the degradation of multi-pollutants.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2021
·Vol. 11
·期 9
·1101
·
IF 2.589
Hui Chen,Cuncun Wu,Ri Li,Hongjian Chen
A three-dimensional cellular automata-lattice Boltzmann (CA-LBM) coupling model is established to simulate the facet growth process and the controlled cooling growth process of Cs2AgBiBr6perovskite single crystals. In this model, the LBM method is used to calculate the real-time solute field, the CA method is used to simulate the crystal growth process driven by supersaturation of solute, and the geometric parametergrelated to the adjacent grid is introduced to reduce the influence of grid anisotropy. The verification of the model is achieved by comparing the simulation results with the experimental results. The comparison results show that a smaller cooling rate is helpful for the growth of large-size single crystals, which verifies the rationality and correctness of the model.
研究领域:
材料科学
·
晶体生长动力学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
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IF 6.2
Weijia Guo,Yutian Lu,Chongyang Zhang,Zhenxing Yue
Low-loss (high- Q × f , where Q = 1/tan δ ) dielectric ceramics can help achieve efficient microwave signal transmission and reduce heat generation. In the traditional Ca-Ln-Ti-O perovskite system (where Ln = rare earth) with the general formula of Ca 1– x Ln 2 x /3 TiO 3 (CST x ), the sharp decline in the Q × f value when x > 0.5 remains unexplained, posing a challenge for designing low-loss ceramics. In this study, CST x ceramics ( x ≤ 0.7) are synthesized via the solid-state reaction method, with a focus on their structure, defects, and broadband dielectric properties. A significant discrepancy between the Q × f values in the microwave and terahertz bands is found when x ≥ 0.6, suggesting the presence of additional loss mechanisms in the microwave band beyond ion displacement depolarization. Meanwhile, the low-frequency dielectric spectra show a weak dielectric relaxation in the low-temperature region, attributed to the partially ordered A -site vacancies. Therefore, this relaxation can act on the microwave frequency band at room temperature, resulting in a sharp decline in Q × f values. Such low-frequency and low-temperature dielectric relaxation should not be ignored in the research of microwave dielectric ceramics. These findings provide a crucial theoretical reference for developing low-loss microwave dielectric ceramics.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Jinsong Luo,Tianci Xiao,Wu Wen,Jun Bao,Chengyuan Liu,Yang Pan
The pursuit for higher light olefin selectivity and extended catalyst lifetime has been a hot topic in the methanol-to-olefins (MTO) process. The incorporation of Ca in HZSM-5 (Ca-modified HZSM-5) could exhibit outstanding catalytic stability and high C3+ olefins yield. In this work, synchrotron radiation photoionization mass spectrometry was applied to study the lifetime enhancement mechanism of Ca-modified HZSM-5. It is interesting to note that the mechanism differs in the cases of different Ca-loading. Under low Ca-loading, the main reason for lifetime enhancement is the modification of acid sites, which limited hydrogen transfer reactions and subsequent coking process. While higher Ca-loading would introduce CaO species over HZSM-5, which showed prominent activity for HCHO elimination. The decomposition of HCHO would suppress the HCHO-mediated aromatic formation pathway during the MTO process, therefore alleviating the coking process. Moreover, the elimination mechanism of HCHO over CaO was investigated using in situ IR measurements. This study provides some additional insights into the role of acid sites and CaO during the Ca-modified HZSM-5 catalyzed MTO process.
研究领域:
催化化学
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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）