APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Chao Feng,Qianqian Gao,Gaoyan Xiong,Yanfei Chen,Yuan Pan,Zhaoyang Fei,Yanpeng Li,Yukun Lu,Chenguang Liu,Yunqi Liu
The low defect content and poor oxygen mobility of perovskite catalysts limit its application in VOC elimination. Herein, we report a strategy involving defect engineering route following an easy urea treatment method to enhance the propane oxidation performance of perovskite catalysts. The constructed LaCoO 3 -D43 exhibits superior catalytic activity (T 90 = 309.3 °C), the T 90 value is 150 °C lower than that of LaCoO 3 , and excellent thermal stability against CO 2 and H 2 O. Experimental results revealed that the urea pyrolysis resulted in the generation of La and O defects and rich surface-active Co species in high-valence states, increasing the utilization of Co active sites. DFT calculations show that the exposed Co surface is conducive to the adsorption and dissociation of oxygen and propane. This work provides a defect engineering strategy to effectively activate perovskite catalysts performance, and can be generalized for the fabrication of other types of perovskite catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Rui Chen,Ying-Ying Wang,Xia Jiang,Ming-Hao Ji,Hao-Yan Shi,Hai-Long Wang,Yan-Xin Chen,Can-Zhong Lu
This article describes a photocatalytic (PC) hydrogen evolution technology that utilizes Pd/LaCoO3/PCN nanocomposites. In the preparation process, a narrow band gap pure LaCoO3 phase was obtained using a template method, which was subsequently combined with Pd-NPs loaded with pCN to form a Z-scheme heterojunction. The formation of this heterojunction resulted in a material with improved charge transfer characteristics and electron well performance. Under visible light irradiation, the composite material demonstrated a higher PC hydrogen evolution activity, resulting in a H2 yield of 40.2 μmol g–1 h–1. This yield represents a 259 times improvement over pure pCN materials, respectively. Furthermore, in the presence of a sacrificial agent, triethanolamine (TEOA), the production of H2 increased compared to methanol, likely due to the more vital binding ability of the amine-containing pCN to TEOA. Finally, the study found that Pd/LaCoO3/PCN nanocomposites displayed excellent stability and reusability during three continuous cycles. These results suggest that this material may become an efficient and sustainable technology for solar fuel production.
研究领域:
材料科学
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可再生能源
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Yanfang Zhu,Xu Jiang,Xiaoyuan Jin,Wenqi Song,Yuzhen Zhao
The catalytic properties of metals and metal oxides are vital for lignin depolymerization into phenolic and cyclohexane compounds production. This study investigated the lignin depolymerization of with different Ni content LaCoO 3 perovskite catalysts at different reaction conditions such as reaction temperature, time, catalysts amount. Furthermore, various hydrogen sources, including formic acid, ethanol, and pure hydrogen were tested. The highest bio-oil yield (75.3 wt%) was achieved with hydrogen under ethanol solvent, but selectivity for cyclohexane and phenolic monomers compound was low. Using formic acid (FA) with 7 % Ni-LaCoO 3 catalysts at 280 °C, a bio-oil yield of 72.4 wt% was obtained, with higher selectivity for 2,6-dimethoxyphenol (19.5 %), cyclohexane (18.5 %), and methylcyclohexane (14.2 %). This suggests that Ni with presence of FA facilitates the cleavage of lignin's β-O (C-O) and β-β (C-C) bonds efficiently. The reaction using FA, resulted in the lowest O/C ratio (0.06), highest H/C ratio (0.14), and the highest HHV (36.6 MJ/kg). The catalyst exhibited the highest reaction rate and hydrogenation activity, attributed to the presence of highly dispersed surface Co and Ni species. Notably, after three recycling test, the Ni-LaCoO 3 catalyst maintained very good catalytic activity. These results suggest that catalysts with this composite support have the potential to convert lignin-derived phenolic compounds into higher-grade hydrocarbon liquid fuels.
研究领域:
能源化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 16
·8554-8560
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IF 3.269
Kuiyuan Wang,Jinzhu Song,Xijian Duan,Jianshuai Mu,Yan Wang
Perovskite LaCoO3 materials (LCO NPs) were prepared and found to possess both peroxidase-like and catalase-like catalytic activities. The LCO NPs can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 generating a blue color change under acidic conditions or decompose H2O2 under alkaline conditions with the generation of oxygen. Catalytic kinetics together with the possible mechanism of the peroxidase-like activity was investigated. The peroxidase-like catalytic properties of LaCoO3 nanoparticles were found to originate from their ability of accelerating electron transfer. Then based on their peroxidase properties, LCO NPs were applied to determine dopamine by using the colorimetric method with the dopamine-dependent successive inhibition reaction. The linear range of dopamine sensing was found to be 0.5–20 μM and the detection limit (LOD) was also discussed. The standard addition experiments were further performed with recoveries between 95.4% and 103.6%, and all the relative standard deviations (RSDs) were below 4.0%. The determination of dopamine therefore showed high accuracy and efficiency and has potential for the diagnosis of dopamine-related diseases.
研究领域:
生物化学
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材料科学
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医学诊断
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2021
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IF 8.198
Jianyi Lei,Jiajun Dai,Kok Bing Tan,Jiale Huang,Guowu Zhan,Qingbiao Li
Direct epoxidation of propylene to propylene oxide (PO) with molecular oxygen as the most atomically economical route remains challenging due to the low PO yield. In this study, CuO supported on perovskites (LaCoO3) modified with NaCl was found to be active for direct epoxidation of propylene with oxygen. LaCoxCu1–xO3– modified with alkali metal salts were further fabricated to improve catalytic performance with the assistance of citric acid. Among the investigated catalysts, LaCo0.8Cu0.2O3−δ exhibited the best catalytic performance, with a PO formation rate of 60.4 gPO·kgcat−1·h−1 (PO selectivity of 10.2% and propylene conversion of 12.0%) at a lower temperature (250 °C). The characterization results indicate that Cu-doped LaCoO3 catalysts with enhanced oxygen vacancies and abundant electrophilic oxygen species are crucial to selectively attack on C═C bond instead of C–H bond. Besides, LaCoxCu1–xO3−δ catalysts demonstrated higher propylene conversion and more stable catalytic performance. This work exemplifies the direct propylene epoxidation with molecular oxygen employing perovskite materials.
研究领域:
催化化学
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材料科学
✓ 已验证
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
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Peng Qiu,Jin Li,Lichao Jia,Bo Chi,Jian Pu,Jian Li,Fanglin Chen
Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) is a promising cathode for intermediate temperature solid oxide fuel cells. However, BSCF cathode performance stability has been a challenge and its electrochemical performance deteriorates severely in the presence of Cr 2 O 3 -forming metallic interconnect. We demonstrate that LaCoO 3-δ (LC) coating on BSCF cathode can not only enhance BSCF electrochemical performance, but also effectively improve the BSCF performance stability. In this study, LC-coated BSCF-Gd 0.1 Ce 0.9 O 1.9 (LC@BSCF-GDC) cathode is prepared through a solution impregnation method and systematically characterized. EIS, XRD, Raman, SEM and EDS tests with and without SUS430 interconnect are conducted to characterize the Cr-tolerance. The results show that BSCF-GDC cathode is susceptible to Cr poisoning while LC@BSCF-GDC cathode has significantly enhanced tolerance to Cr poisoning. Single cells with LC@BSCF-GDC cathode achieve higher peak power density and smaller polarization resistance values than single cells with BSCF-GDC cathode. Furthermore, significant improvement of performance stability under a constant current load has been achieved for single cells with LC@BSCF-GDC cathode. This work provides a new solution for solving BSCF cathode performance stability.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
·
IF 6.2
Lei Liu,Yueyue Li
The spinel and perovskite-based heterogeneous catalysts play indispensable roles in the sulfate radical-based advanced oxidation process (SR-AOP). In this study, novel electrospun boron-doped NiCo 2 O 4 /LaCo 1−x B x O 3 (NCO/B x , 0 ≤ x < 1) catalysts were constructed using defect and interface engineering to accelerate peroxymonosulfate (PMS) activation. Due to the synergistic impacts of oxygen vacancies (OVs) and heterointerfaces, NCO/B 0.2 demonstrated improved catalytic performance toward the degradation of Orange II (Org II). The NCO/B 0.2 catalyst showed a high degree of pH tolerance, with a range of 5.0–11.0, while maintaining a removal rate of 94.2% even after five cycles. The degradation pathway exhibited a preference for non-radical mechanisms, with singlet oxygen ( 1 O 2 ) being the dominant reactive oxygen species. The synthesis method for NCO/B x exhibits the potential to facilitate rational design and large-scale production of exceptionally effective heterostructured catalysts.
研究领域:
环境科学
·
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Jiahao Chen,Yiqing Zeng,Shule Zhang,Zhaoxiang Zhong,Qin Zhong
Interface interaction existed in the multicomponent determines the catalytic performance of composite catalysts. Herein, a Co 3 O 4 -LaCoO 3 (Co-La) composite catalyst with strong spinel-perovskite interface interaction was successfully synthesized via a one-pot sol-gel method for the catalytic oxidation of toluene. The activity test results showed that the optimal 1Co 3 O 4 –4LaCoO 3 (1Co-4La) catalyst exhibits much higher catalytic activity (T 90 = 215 °C, GHSV = 50,000 h −1 ) than Co 3 O 4 (T 90 = 295 °C), LaCoO 3 (T 90 = 256 °C) and 1Co 3 O 4 /4LaCoO 3 (1Co/4La) (prepared by mechanical ball-milling, T 90 = 285 °C). Characterizations revealed that the strong spinel-perovskite interface interaction generated between the Co 3 O 4 spinel and LaCoO 3 perovskite in 1Co-4La facilitates the transfer of interfacial electrons, contributing to the exposure of surface active Co 3+ and the enhanced oxidation ability of surface active Co 3+ on 1Co-4La. In addition, the reactive lattice oxygen of surface Co 3+ –O on 1Co-4La effectively promotes the decomposition of toluene into CO 2 , enabling the low-temperature oxidation of toluene through the Mars-van Krevelen (MvK) mechanism. This work provides insight into the promotional effect of multicomponent interface interaction on enhancing catalytic performance of spinel-perovskite composite catalysts.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Yan He,Jinpeng Guo,Chuanchuan Bi,Zhifei Hao,Bin Zhao,Chunping Li,Xiaogang Han,Qi Wang
Composite polymer electrolytes (CPE) have attracted considerable attention due to their potential to achieve high flexibility and large energy density. However, their practical application is hampered by their suitability at a single temperature and severe lithium dendrite growth. In this work, we have doped the perovskite inorganic filler LaCoO 3 into polyamide (PI) nanofibers and constructed a LaCoO 3 /PI/PVDF CPE. Electrochemical characterization of the CPE and density functional theory calculations performed for it show that perovskite nanofibers have abundant oxygen vacancies, which are conducive to accelerating the dissociation of lithium salts and releasing more free lithium ions. Li//Li symmetric batteries exhibit excellent long cycle performance (over 3000 h) at 30 °C, and LiFePO 4 //Li batteries exhibit excellent cycling performance with over 1000 cycles at (0.5 C, 30 °C) and 400 cycles at (0.2 C, 60 °C), which can be realized with high voltage cathode NMC 811. The physical properties of the CPEs are also quite outstanding, with good thermal stability as it can withstand a high temperature of 200 °C and tensile strength up to 12.01 MPa. This work presents a new idea for designing CPEs with high safety and excellent electrochemical properties, which can provide stable circulation over a wide temperature range.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL SCIENCES
·
2022
·Vol. 134
·期 2
·1-12
·
IF 2.15
Li Wenyu,Zhu Yumei,Guo Wei,Xu Hanwen,Gong Cairong,Xue Gang
This report designed a Pt/LaCoO 3 composite electrocatalyst for electrochemical water splitting: LaCo 0.94 Pt 0.06 O 3 was prepared via the sol-gel method and then dealt with a heat treatment in 10% H 2 /Ar atmosphere at 350 °C. The XRD, HRTEM, SEM and XPS results show that the Pt nanoparticles (NPs) exsolve from the perovskite lattice and are homogeneously distributed on the surface. The HER and OER performance of the samples was tested in 1 mol·L -1 KOH solution and the findings illustrate that compared with LaCo 0.94 Pt 0.06 O 3 , Pt/LaCoO 3 owes better OER and HER performance. The improved performance could be up to the higher ratio of oxygen vacancies and improved charge transfer. Furthermore, the synergistic effect between Pt NPs and the LaCoO 3 matrix may also take a leading part in the future. Graphical abstract Figure SEM images of the samples: (a) LaCo 0.94 Pt 0.06 O 3 ; (b) Pt/LaCoO 3 . After the exsolution, the Pt/LaCoO 3 is well-developed with smooth surface and some nanoparticles are homogeneously distributed on the surface of the samples. The exsolved Pt nanoparticles can accelerate the electron exchange process between the matrix and its adsorbed intermediates, and ultimately promote the electrochemical reaction kinetics.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2023
·Vol. 108
·期 3
·721-733
·
IF 2.5
Chen Gaokui,Shen Qiuwan,Li Shian,Zhang Xin,Cai Zhongwen,Yang Guogang
The CuO modified LaCoO 3 @CuO-x catalysts were prepared through sol-gel method, and applied for methanol steam reforming (MSR). The catalysts were characterized by means of XPS, XRD, SEM, BET, TEM and EDS techniques. XPS and XRD analyses show that the synthesized catalysts are the combination of LaCoO 3 and CuO. The results of XPS also demonstrated that the Co ion in perovskite exhibits a mixed valence state of Co 3+ and Co 2+ , and the presence of Co 2+ contributes to the reduction of Cu 2+ to copper and also promotes the formation of hydrogen. The results of SEM and TEM show that LaCoO 3 @CuO-0.2 catalyst with core-shell type has porous structure, which contributes to expedite the contact between the reaction medium and the catalyst surface, therefore, improving the catalytic performance. The results of the pore size show that LaCoO 3 @CuO-0.2 exhibits remarkably large pores compared with other catalyst samples. The MSR experimental results illustrate that LaCoO 3 @CuO-0.2 has the optimal catalytic performance, and the methanol conversion of LaCoO 3 @CuO-0.2 is 100%. In addition, the stability of LaCoO 3 @CuO-0.2 was evaluated under the optimum operating parameters (the catalytic temperature, LHSV and W/M are 873 K, 20 h −1 and 4:1, respectively). The results show that the developed LaCoO 3 @CuO-0.2 has excellent stability within 50 h without deactivation. Graphical abstract
The LaCoO 3 @CuO-0.2 developed in this study with core-shell structure has outstanding catalytic performance and excellent stability. The presence of Co 2+ proves the existence of oxygen vacancies on the surface of the catalyst, which is helpful for the reduction of Cu 2+ to copper and promotes the MSR reaction.
研究领域:
材料科学
·
催化化学
✓ 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）