Carbon Capture Science & Technology
·
2021
·
IF 0
Yuxin Mei,Nicui Yuan,Yuwei Liu,Xin Zhang,Baining Lin,Yonghua Zhou
Boron carbon nitride (BCN) is an emerging metal-free catalyst for CO 2 photocatalytic reduction. However, the fast electron-hole recombination as well as the weak absorption for ultraviolet-visible (UV-vis) light are still challenging for the activity upgrading of BCN. In this paper, a BCN/CeO 2 heterostructure via N-O-Ce bonding was fabricated by a urea-assistant heat-precipitation technique and confirmed by XRD, FT-IR, SEM, TEM and XPS characterizations. For CO 2 photoreduction with H 2 O as reducing agent, the BCN/CeO 2 heterostructure delivered an obviously enhanced catalytic performance with CO yield of ca. 6-fold that of BCN. UV-vis diffuse reflectance spectrophotometer (DRS), electrochemical impedance spectroscopy (EIS) and transient photocurrent response measurements revealed that the electron-hole separation efficiency and charge transfer are efficiently promoted on CeO 2 /BCN heterostructure, along with the boosted light harvesting in visible and ultraviolet light range. Furthermore, based on the photo(electro)chemical and photocatalytic results, a possible CO 2 photocatalytic reduction mechanism was proposed.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
DOI
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Zhengjiang Liu,Dan Zhou,Huiyan Ma,Lei Xing,Qiancheng Zhang,Juming Liu
SO 4 2− /CeO 2 /TiO 2 composite oxides are successfully fabricated via sol-gel method and impregnation process for photocatalytic H 2 production. The characterization results from XRD, FTIR and TEM revealed that the heterojunctions were formed by the formation of Ti-O-Ce bond across the SO 4 2− /CeO 2 /TiO 2 interface, which was contributed significantly to separation of photo-generated carriers. Py-FTIR spectra and XPS results indicated that Lewis acid and Brønsted acid sites were formed over the surface of SO 4 2− /CeO 2 /TiO 2 composite, which was owing to SO 4 2− coordinated to the metal on the sample surface. The induced Lewis acid sites could enhance the separation of photogenerated carriers, and Brønsted acid sites could provide protons for photocatalytic H 2 production. In addition, the Lewis acidity could facilitate the shift of conduction band minimum to a more negative value, which improves the photocatalytic H 2 production capacity of SO 4 2− /CeO 2 /TiO 2 . The results of photocatalytic H 2 production revealed that SO 4 2− /CeO 2 /TiO 2 composite exhibits superior photocatalytic activity compared to bare CeO 2 , TiO 2 and CeO 2 -TiO 2 composite. Notably, it achieves the average H 2 yield rate of 6295.2 μmol· g −1 h −1 over a period of 5 h. Combine the results of spectra analysis and photocatalytic activity H 2 evolution, it can be concluded that the synergetic effects of heterojunction structure of CeO 2 /TiO 2 composite and acid impregnation promoted the photocatalyst activity.
研究领域:
材料科学
·
催化化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yujing Xie,Chenhui Qiu,Lei Wang,Yuxuan Wang,Jie Zhang,Jinfeng Zhang,Hui Wan,Guofeng Guan
Photocatalytic CO 2 reduction to fuels via visible light is regarded as a highly promising sustainable technology to address resource depletion and environmental apprehensions. However, the elevation of photocatalytic performance is limited due to some drawbacks of isolated catalysts such as poor CO 2 adsorption performance, inadequate utilization of visible light, and rapid recombination of photo-generated carriers. Herein, a series of novel heterojunction catalysts, 1D/2D CeO 2 /Bi 2 MoO 6 (CBMO-X), were fabricated utilizing the microwave-assisted method for the photocatalytic reduction of CO 2 . The CH 3 OH yield of the optimized CBMO-10 composite material reached 4.31 μmol⋅g −1 ⋅h −1 with excellent stability and structural integrity. Through a series of characterizations, it was found that the introduced CeO 2 nanorods served as bifunctional sites for CO 2 adsorption and photoelectron accumulation, effectively promoting CO 2 conversion under visible light. In addition, CBMO-X exhibited faster photo-generated carriers migration rate due to the formation of the II-scheme heterojunction, which improved the photocatalytic performance obviously. Furthermore, the density functional theory (DFT) calculations and in situ XPS were used to investigate the carrier migration paths on the surface of composite materials. This work provided a novel strategy for the design of photocatalysts for efficient CO 2 conversion.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2017
·Vol. 7
·期 10
·2129-2139
·
IF 5.773
Houlin Wang,Shuang Liu,Zhen Zhao,Xin Zou,Minghan Liu,Wei Liu,Xiaodong Wu,Duan Weng
Different Ag/CeO2 catalysts with uniform structures and diverse surface oxygen vacancy (VO-s) contents were synthesized via a modified solution combustion method. Based on the results of Raman spectroscopy, H2-TPR and isothermal soot oxidation, it was suggested that even with gaseous O2 participating in the reaction, ceria surface sites around the catalyst–soot contact points can still be reduced by soot gradually. This interfacial reduction led to the generation of extra VO-s without changing the oxygen vacancies in the bulk of CeO2. Notably, this VO-s dynamic change and the insufficient O2− regeneration/delivery further resulted in the activation and deactivation of Ag/CeO2 during reaction with soot. This means that both the existence of ceria VO-s and its dynamic change during reaction may have a crucial influence on catalyst behavior. By further exploring these activity variations, the VO-s content, catalyst–soot contact condition and extra oxygen supplier were proved to be the three most important structural factors behind the soot oxidation activity of all the ceria-based catalysts. In this sense, Ag/CeO2 catalysts with appropriate morphology and moderate initial VO-s content may exhibit good activity for soot oxidation.
研究领域:
催化化学
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环境科学
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材料科学
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表面化学
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能源化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
·
IF 20.2
Fu Li,Qian Huo,Xiaomei Zhou,Shasha Fang,Fei Han,Jingnan Yang,Qingxin Guan,Wei Li
Photothermal CO 2 into methanol is an effective approach to address energy and environmental challenges, but the low conversion and poor selectivity limit its large-scale application. Here, 0.5Cu@CeO 2 with atomically dispersed active sites and abundant Frustrated-Lewis-pairs (FLPs) was synthesized using coordination complex precipitation reaction. The substitution of Cu 2+ with Ce 3+ results in the formation of new FLPs, which promotes the upward shift of conduction band (CB) and enhances the reducing capability of catalyst. Moreover, the more sensitive and stronger capability of photogenerated carriers also endows 0.5Cu@CeO 2 with stronger CO 2 reduction capability. The photothermal methanol yield of 0.5Cu@CeO 2 reached 1896.02 μmol·g cat –1 ·h –1 . The DFT results demonstrate the FLPs structure of 0.5Cu@CeO 2 promotes parallel adsorption of CO 2 and *CO species. Meanwhile, the presence of O v inhibits the dissociation of oxygen species, consequently boosting the methanol synthesis. The construction of FLPs structure introduces a novel method to enhance CO 2 conversion utilizing photothermal catalysis.
研究领域:
催化
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材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Shumail Farhan,Asif Hassan Raza,Songyu Yang,Zhixian Yu,Yan Wu
The advancement of highly effective heterojunction photocatalysts with improved charge separation and transfer has become a crucial scientific perspective for utilizing solar energy. In this study, we developed the S-scheme heterostructure by depositing N-doped CeO 2-δ (NC) nanoparticles onto two-dimensional ZnIn 2 S 4 (ZIS) nanosheets via hydrolysis strategy for significantly enhanced photocatalytic hydrogen evolution reaction. The optimal H 2 generation rate of ∼ 798 μmol g –1 h –1 was achieved for NC-3@ZIS under solar light irradiation, which is about 18 and 2 times higher than those of pristine CeO 2 (∼44 μmol g –1 h –1 ) and ZIS (∼358 μmol g –1 h –1 ), respectively. The photogenerated electrons from NC interact with the photogenerated holes of ZIS driven by an internal electric field, confirmed by In-situ KPFM, DFT calculation, and XPS results. According to EPR and photoelectrochemical measurements, NC-3@ZIS composite shows dramatically high separation efficiency of photogenerated charge carriers. This study provides a new approach for developing non-noble metal S-scheme heterojunctions with enhanced photocatalytic hydrogen evolution.
研究领域:
材料科学
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能源科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Donglin Huang,Wulin Song,Hongmei Zhao,Meng Li,Liang Wei,Hongxi Zhang
There are limited renewable sources of aromatic chemicals, with lignin being one of the most prominent, accounting for approximately 30% of the planet's organic carbon. Due to its intricate and irregular structure, lignin is recalcitrant to chemical conversion, often resulting in low yields of mixtures of products when it is depolymerized. This study synthesized a CeO 2 /AC catalyst via an impregnation technique and then explored its ability to depolymerize lignin via an oxidation-reduction strategy. The CeO 2 /AC catalyst efficiently depolymerized lignin by an oxidation-reduction strategy. At 200 °C, an argon pressure of 1 MPa, and a reaction time of 4 h, the conversion of the lignin model compound reached 98.5%. When using lignin derived from poplar, birch, pine, and cotton stalk, the total yields of phenolic monomers were 36.2 wt.%, 31.2 wt.%, 17.4 wt.%, and 12.1 wt.%, respectively. The CeO 2 /AC catalyst exhibited a higher surface oxygen vacancy concentration than CeO 2 , which was crucial for facilitating the hydrogenolysis of lignin.
研究领域:
催化化学
·
可再生资源转化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Haiwen Xu,Danyang Li,Lei Jiang,Chunqiang Lu,Jiangyong Yuan,Zhiqiang Li,Yuelun Li,Huicong Zuo,Kongzhai Li
It is challenging to load precious metals nanoparticles on LaFeO 3 perovskite with small specific surface, and to improve the thermal stability of precious metals is also very difficult. Therefore, it is of great significance to disperse precious uniformly on perovskite with low specific surface area and to make the catalyst with high catalytic activity and thermal stability. In this work, we develop series of perovskite-based methane combustion catalysts with good catalytic activity and stability. Compare with traditional LaFeO 3 catalysts, the catalytic activity of three-dimensional ordered macroporous (3DOM) LaFeO 3 significantly improves by loading Pt. In addition, its thermal stability is significantly improved by adding CeO 2 , especially at high roasting temperature (800 °C). The 1 wt%Pt/10 %CeO 2 /3DOM LaFeO 3 catalysts shows the highest catalytic activity in which the T 10 , T 50 and T 90 are 362 °C, 433 °C and 502 °C, and its recaction temperature of T 50 is decreased by 50 °C compare with Pt/3DOM LaFeO 3 (8 0 0). The different physical and chemical characterizations suggest that the coupling of Ce 3+ and Fe 2+ induces the formation of a large number of oxygen vacancies, which promotes the oxygen mobility and th oxygen storage capacity during the methane oxidation process. More importantly, the CeO 2 addition contributes to the Pt-CeO 2 interaction with Ce-O-Pt bond formation, which greatly improves the thermal stability of the catalyst, and this Pt-CeO 2 interaction strength becomes more obvious with the increase of calcination temperature. Furthermore, the in-situ DRIFT experiments indicate that M−K mechanism is probably involved in the reaction process.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2022
·
IF 4.804
Xiao-Chun Deng,He Zhang,Guo-Hua Zhang
Combining spray drying and in-situ synthesized technology, WC-10Co cemented carbides with uniform composition was prepared by vacuum sintering to investigate the effects of different CeO 2 contents (0 wt%, 0.5 wt%, 1 wt%, 2 wt%, 4 wt%) as well as co-doping with CeO 2 and VC on the microstructure and mechanical properties . With increasing CeO 2 addition from 0 wt% to 0.5 wt%, the WC grain size decreased from 0.79 ± 0.35 μm to 0.62 ± 0.24 μm. The hardness, fracture toughness and transverse rupture strength (TRS) of the alloy with 0.5 wt% CeO 2 all reached the maximum values of 1752 ± 28 HV 30 , 18.50 ± 0.35 MPa·m 1/2 and 2245 ± 35 MPa, respectively, which indicated that the mechanical properties of cemented carbide could be simultaneously improved by adding 0.5 wt% CeO 2 to refine the WC grains. However, as the CeO 2 content increased to 4 wt%, the hardness gradually decreased, while the fracture and TRS all slightly decreased first and then tended to be stable. Moreover, the corrosion resistance of alloys first increased and then decreased with the increase of CeO 2 content. The 0.5 wt% CeO 2 alloy had the best corrosion resistance. After adding 0.5 wt% VC, the grain size of alloys became smaller and distribution of Co binder was more uniform. Compared to the samples with only added CeO 2 , the alloy with co-addition of 0.5 wt% CeO 2 and 0.5 wt% VC exhibited the best comprehensive mechanical properties. The hardness, fracture toughness and TRS of the alloy with co-addition of 0.5 wt% CeO 2 and 0.5 wt% VC were 1987 ± 44 HV 30 , 16.10 ± 0.34 MPa·m 1/2 and 2023 ± 78 MPa, respectively.
研究领域:
材料科学
·
冶金学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Ji Zhao,Xian-Yong Wei,Jing-Hui Lv,Qian-Qian Kong,Jia-Hao Li,Zhuang Li,Zi-Chun Fan,Li Li,Yang-Yang Zhang,Zhi-Min Zong
Ni/CeO 2 with medium-strong acidity was prepared by in - situ carbon templating (ISCT) and reduction with H 2 . Oxydibenzene (ODB) and benzyloxybenzene (BOB) were used as lignin-related model compounds (LRMCs). Over Ni/CeO 2 , ODB was completely converted into cyclohexane ( CH I ) under initial hydrogen pressure (IHP) of 2 MPa at 160 °C for 2 h and complete conversion of BOB to CH I and methylcyclohexane (MCH) was achieved under IHP of 2 MPa at 120 °C for 1.5 h. H … H transfer to the benzene rings (BRs) in the LRMCs and phenol from BOB hydrocracking results in the BR hydrogenation, while H + transfer to the oxygen atom in BOB, hydrogenated ODB, and BOB-derived cyclohexanol ( CH II ) leads to the >CH-O- bond cleavage and subsequent dehydration of the resulting protonated CH II (PCH II ) . In addition, Ni/CeO 2 exhibits an excellent reusability.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Muhammad Akbar,Zhengwen Tu,Bin Jin,Naveed Mushtaq,Zili He,Wenjing Dong,Baoyuan Wang,Xunying Wang,Chen Xia
Nowadays, lowering the operating temperature of solid oxide fuel cells (SOFCs) is a major challenge towards their widespread application. This has triggered extensive material studies involving the research for new electrolytes and electrodes. Among these works, it has been shown that CeO 2 is not only a promising basis of solid oxide electrolytes, but also capable of serving as a catalytic assistant in anode. In the present work, to develop new electrolytes and electrodes for SOFCs based on these features of CeO 2 , a new type of functional composite is developed by introducing semiconductor CuO into CeO 2 . The prepared composites with mole ratios of 7:3 (7CeO 2 –3CuO) and 3:7 (3CeO 2 –7CuO) are assessed as electrolyte and anode in fuel cells, respectively. The cell based on 7CeO 2 –3CuO electrolyte reaches a power outputs of 845 mW cm −2 at 550 °C, superior to that of pure CeO 2 electrolyte fuel cell , while an Ce 0.8 Sm 0.2 O 2-δ electrolyte SOFC with 3CeO 2 –7CuO anode achieves high power density along with open circuit voltage of 1.05 V at 550 °C. In terms of polarization curve and AC impedance analysis, our investigation manifests the developed 7CeO 2 –3CuO composite has good electrolyte capability with a hybrid H + /O 2− conductivity of 0.1–0.137 S cm −1 at 500–550 °C, while the 3CeO 2 –7CuO composite plays a competent anode role with considerable catalytic activity , indicative of the dual-functionalities of CeO 2 –CuO in fuel cell. Furthermore, a bulk heterojunction effect based on CeO 2 /CuO pn junction is proposed to interpret the suppressed electrons in 7CeO 2 –3CuO electrolyte. Our study thus reveals the great potential of CeO 2 –CuO to develop functional materials for SOFCs to enable low-temperature operation.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Yu Lei,Yixing Hao,Hao Cheng,Jianfeng Ma,Yong Qin,Yong Kong,Sridhar Komarneni
Fe 2 O 3 @CeO 2 nanocomposites were synthesized by water bath heating method to activate NaHSO 3 for Orange II dye (50 mg L −1 ) degradation, which reached up to 98.2% within 120 min. The Fe 2 O 3 @CeO 2 and NaHSO 3 dosages and the molar ratios of Ce and Fe in Fe 2 O 3 @CeO 2 were investigated to obtain the optimum conditions as follows: 0.02 g Fe 2 O@CeO 2 , 0.1 g NaHSO 3 and the molar ratio of Ce and Fe was 5:2 (designated as Ce-Fe-1, or simply Fe 2 O 3 @CeO 2 ). In addition, Fe 2 O 3 @CeO 2 catalyst displayed superior catalytic performance to those materials that were previously reported, as verified by the good stability (reached 90.9% after three cycles) and high degradation rate of Orange II (98.2%) of the currently developed material. Existence of · SO 4 – and · OH radicals were verified by Electron Spin Resonance Spectroscopy during degradation, and these radicals are proposed to have high degradation efficiency of Orange II. On the basis of the detected radicals, a possible degradation mechanism was proposed to provide more choices for the application of sulfite in advanced oxidation processes (AOPs).
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）