PHYSICA B-CONDENSED MATTER
·
2021
·
IF 2.436
Yihang Dong,Zhaoyang Liu,Lipeng Pang,Ye Han,Shuyu Yao,Xiangnan Wang
{(Y 2 O 3 ) 0·08 (ZrO 2 ) 0.92 } 1- x (CeO 2 ) x (0 ≤ x ≤ 0.6) is synthesized by co-precipitation method. Thermal analysis, phase structure, lattice constant , micro-morphology, elements distribution, density, open porosity and electrical conductivity are measured by TG, DSC , XRD , GSAS, SEM , EDS, Archimedes method and EIS respectively, and the influence of CeO 2 content on the above properties are investigated. TG-DSC results show that the weight loss of the sample is mainly due to the decomposition of the initial powder, forming a solid solution above ~600 °C. XRD results show that {(Y 2 O 3 ) 0·08 (ZrO 2 ) 0.92 } 1- x (CeO 2 ) x (0 ≤ x ≤ 0.6) is a cubic solid solution, and the lattice parameters and volume increase with the increase of CeO 2 content. SEM results show that YZC is a dense sintered body. Density and open porosity of YZC sample are ~4.5 g cm −3 and ~0.12, respectively. The electrical conductivity results show that the conductivity of {(Y 2 O 3 ) 0·08 (ZrO 2 ) 0.92 } 1- x (CeO 2 ) x (0 ≤ x ≤ 0.2) is equivalent, and then the conductivity decreases due to defect association with the increase of CeO 2 content.
研究领域:
材料科学
·
陶瓷材料
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Yutong Pan,Pengju Gao,Shixiong Tang,Xiaoyu Han,Ziwen Hao,Jiyi Chen,Zhenmei Zhang,Heng Zhang,Xiaohui Zi,Maoshuai Li,Shiwei Wang,Yue Wang,Xinbin Ma
This work synthesized a series of Ni/CeO 2 /Al 2 O 3 catalysts with varying CeO 2 doping amounts to enhance low-temperature CO 2 methanation. The introduction of CeO 2 weakens the interaction between Ni and Al 2 O 3 , leading to the formation of Ni-CeO 2 active sites. This results in a high dispersion of Ni and CeO 2 , improved catalyst reducibility, increased number of active sites, and enhanced the CO 2 methanation. This work further investigated the impact of WHSV and catalyst stacking configuration to enhance the reaction. When the catalyst is stacked into three segments with a temperature gradient of 330 °C, 300 °C, and 250 °C under WHSV=9000 ml·h –1 ·(g cat) –1 , the CO 2 conversion significantly increases to 95%, which is remarkably close to the thermodynamic equilibrium (96%).
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
ACS Catalysis
·
2020
·
IF 12.35
Feng Jiang,Shanshan Wang,Bing Liu,Jie Liu,Li Wang,Yang Xiao,Yuebing Xu,Xiaohao Liu
CeO2 is an excellent potential material for CO2 hydrogenation attributed to the highly tunable properties including metal–support interaction and abundant oxygen vacancy. In this work, four CeO2 supports with structurally well-defined different shapes and crystal facets are hydrothermally prepared, and their effects on the composition of Pd species and oxygen vacancy over Pd/CeO2 catalysts have been intensively investigated in the reduction of CO2 to methanol. The 2Pd/CeO2-R (rods) shows the highest concentration and number of oxygen vacancies, where the (110) facet with high surface oxygen mobility and low oxygen vacancy formation energy is exposed over the CeO2-R surface. The oxygen mobility at the interface of (111) and (100) facets mainly observed on 2Pd/CeO2-P (polyhedrons) is higher than the single (111) and (100) facets mainly observed on 2Pd/CeO2-O (octahedrons) and 2Pd/CeO2-C (cubs), respectively. The presence of Pd highly promotes the formation of oxygen vacancies by providing dissociated H atoms to facilitate the removal of surface O in ceria support under a H2 atmosphere. Both the PdxCe1–xOδ solid solution dominated on CeO2-R and the PdO species dominated on CeO2-O are reduced to metallic Pd after reduction with 6–10 nm average particle size. As revealed by density functional theory (DFT) calculations, in contrast to the single Pd0 atom on CeO2 and the thermodynamically most unstable PdxCe1−xOδ solid solution, the Pd0 nanoparticles are the most stable species under the realistic reaction conditions. The 2Pd/CeO2-R shows the highest catalytic activity as the abundantly available oxygen vacancies function as CO2 adsorption and activation sites. Moreover, oxygen vacancy reactivity is correlated with its formation energy. The lower formation energy facilitates the formation of oxygen vacancy; however, the reactivity of each oxygen vacancy is lower as the TOFoxygen vacancy of 2Pd/CeO2-O is 15 times as that of 2Pd/CeO2-R. Thus, a suitable oxygen vacancy formation energy is likely favorable for enhancing CO2 reactivity. DFT calculations indicate that the CH3OH formation is most probably from the formate (HCOO*) pathway via the C–O bond cleavage in H2COOH*, with the reduction of HCOO* to HCOOH* as the rate-limiting step. These results would provide experimental and theoretical insights into the rational design of an effective catalyst for CO2 hydrogenation.
研究领域:
催化化学
·
材料科学
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Mingzhen Huang,Jinxin He,Kaiji Xu,Dongren Cai,Guowu Zhan
The supported Pt/CeO 2 catalysts are widely used for the catalytic oxidation of CO at ambient conditions. Herein, we reported a new strategy for modifying the interaction between Pt and CeO 2 support via pulsed steam treatment, which significantly optimized the catalytic performance of Pt/CeO 2 for CO oxidation. Specifically, the hollow CeO 2 nanospheres were prepared by using carbon spheres as sacrificial templates and then subjected to pulsed steam treatment at 150 °C for different times to obtain the CeO 2 -xH support (x means the time of pulsed steam treatment, min). It was found that the complete oxidation of CO can be achieved at 90 °C over the Pt/CeO 2 –50H sample, which was much lower than that (130 °C) on Pt/CeO 2 without pulsed steam treatment. The XPS and in-situ DRIFTS characterizations were conducted to reveal the high performance of the Pt/CeO 2 –50H catalyst for CO oxidation. It was found that the valence state of Pt significantly controlled by pulsed steam treatment was critical to the catalytic activity, whereby the presence of two types of active sites (Pt 0 -CO and Pt δ+ -CO) over Pt/CeO 2 –50H greatly promoted the combination of adsorbed CO and O 2 to generate CO 2 . Accordingly, this study provides a facile method to regulate the Pt valence state by pulsed steam treatment for CeO 2 support, which is critical to the CO oxidation activity.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Kai Shi,Yang Deng,Xia An,Xu Wu,Xianmei Xie
This work focused on optimizing the synergistic effect between CeO 2 and Ni in CeO 2 modified Ni/MgAl 2 O 4 . Six catalysts for ethanol steam reforming (ESR), including NiCeMgAl, CeO 2 /NiMgAl, Ni/CeMgAl, Ni-CeO 2 /MgAl 2 O 4 , Ni/CeO 2 /MgAl 2 O 4 and CeO 2 /Ni/MgAl 2 O 4 , were synthesized by sol–gel and/or impregnation methods, which controlled the introduction order of Ce(NO 3 ) 3 . Ni/CeMgAl showed a satisfactory stability with 90.6 % of ethanol conversion after 100 h test, 66.9 % of H 2 concentration in product, and an excellent anti-coking ability with 0.72 mg c /(g cat ·h). The optimal catalytic performance of Ni/CeMgAl benefits from the unique distribution of components, which provides adequate Ni 0 active sites for C-C bonds scission, maintains a stable particle size of metallic Ni, and suppresses the side reactions and carbonization of intermediates on CeO 2 sites. This work illuminates the important of coordinating the ability of Ni and CeO 2 for ESR and presents a new insight into the design of low-cost and high-performance catalysts in practical applications.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Long Xie,Bin Hu,Riyang Shu,Zhipeng Tian,Ying Chen,Chao Wang
Methanol reforming has been a popular pathway to produce hydrogen due to the high hydrogen storage density of methanol. CeO 2 as the support is widely used for catalytic methanol reforming, but the effect of CeO 2 morphology on the reaction mechanism has not been revealed out. In this study, the catalytic performances of Ru/CeO 2 with different CeO 2 morphology, including rod , cubic and their mixed, were investigated in methanol reforming for the production of hydrogen. By regulating the temperature during hydrothermal preparation, different CeO 2 supports can be achieved. Results showed that Ru/CeO 2 catalyst with rod CeO 2 (Ru/r-CeO 2 ) exhibited a much better catalytic performance than the cubic catalyst (Ru/c-CeO 2 ) and the mixed catalyst (Ru/m-CeO 2 ), with a higher yield of hydrogen and a lower selectivity of CO product. This was mainly due to the large surface area that favored the dispersion of Ru metal site and the interaction between Ru and CeO 2 support that improved the electron transfer to benefit the formation of oxygen vacancy . Therefore, the Ru/r-CeO 2 catalyst possessed abundant oxygen vacancy , which enabled to adsorb the methanol efficiently and trigger the methanol reforming reaction . It also can enhance the adsorption of CO and water and promote the water-gas-shift reaction to increase the yield of hydrogen production .
研究领域:
催化化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Kuan Ding,Hao Zhou,Yiling Wan,Yong Huang,Yuming Zhang,Xun Hu,Hong Zhang,Shu Zhang
Ketonization of biomass-derived oxygenates provides an efficient way for bio-oil upgrading. However, little information on the ketonization of oxygen-rich sugars has been reported, leaving the deep deoxygenation of biomass an unsolved challenge. To address the problem, this paper investigated the catalytic pyrolysis of xylose over nano-CeO 2 using an analytical pyrolyzer . Results showed that upon the addition of CeO 2 , multi-functional oxygenated compounds from xylose pyrolysis were majorly reformed to mono-functional ketonic products, resulting in a 5-fold increase in peak area of ketones . Among them, acetone and 2-butanone presented the highest selectivity of 51% with the CeO 2 to xylose ratio of 10:1 at the temperature of 600 °C. Meanwhile, the short-chain oxygenates, i.e. C 2 -C 3 aldehydes and alcohols, had been converted into C 3 -C 5 ketones, indicating an outstanding ability of chain-increasing over CeO 2 . Both the catalyst dosage and the pyrolysis temperature play a vital role during the ketonization process. The reaction mechanism was proposed according to the experimental results, in which three major reaction pathways were analyzed. This study demonstrates that ketonization of biomass-derived sugars is a promising method for oxygen removal and carbon chain increase, thus improving the bio-oil quality.
研究领域:
生物质能
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2019
·Vol. 25
·期 23
·5904-5911
·
IF 5.16
Guoqiang Liu,Zhiqing Cui,Miaomiao Han,Shengbo Zhang,Cuijiao Zhao,Chun Chen,Guozhong Wang,Haimin Zhang
Graphical Room at the active site : A room-temperature redox approach is used to prepare a composite core–shell-structured Au@CeO 2 electrocatalyst (see figure) composed of small gold nanoparticles (<10 nm) and rich oxygen vacancies in CeO 2 nanoparticles to synergistically boost the electrocatalytic activity toward the N 2 reduction reaction (NRR) to NH 3 . Electrosynthesis of NH 3 through the N 2 reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy- and capital-intensive Haber–Bosch process. Herein, a room-temperature spontaneous redox approach to fabricate a core–shell-structured Au@CeO 2 composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as-synthesized Au@CeO 2 possesses a surface area of 40.7 m 2 g −1 and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH 3 yield rate of 28.2 μg h −1 cm −2 (10.6 μg h −1 mg −1 cat. , 293.8 μg h −1 mg −1 Au ) and a faradaic efficiency of 9.50 % at −0.4 V versus a reversible hydrogen electrode in 0.01 m H 2 SO 4 electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO 2 nanoparticle shell of Au@CeO 2 ; these are favorable for N 2 adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO 2 nanoparticle shell, combined with the Au nanoparticle core of Au@CeO 2 , are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N 2 into NH 3 .
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2023
·
IF 5.5
Lu Ji,Fang Li,Conghui Che,Wei Xue,Qiusheng Yang,Xiaoshu Ding,Dongsheng Zhang,Xinqiang Zhao,Yanji Wang
In the reaction of dimethyl carbonate (DMC) and 2,4-diaminotoluene (TDA), Au/CeO 2 exhibits higher selectivity than CeO 2 for dimethyl toluene-2,4-dicarbamate (TDC). However, its catalytic activity drops after H 2 reduction (denoted as Au/CeO 2 -R). The characterization results illustrate that Au exists as a single atom with the primary species as Au δ+ in Au/CeO 2 , forming Ce x Au 1−x O 2 structure similar to solid solution. Whereas for Au/CeO 2 -R catalyst, Au mainly exists as Au 0 , forming the Au-O-Ce structure on CeO 2 surface. Significantly, the strong interaction between Au and CeO 2 increases Ce 3+ and oxygen vacancies content, as well as modulates their acidic property. However, the catalytic activity of Au/CeO 2 -R is found to be lower than Au/CeO 2 as the species formed by DMC dissociation on its surface are not easily desorbed. Other transition metals supported on CeO 2 are also prepared, wherein Pt/CeO 2 and Pd/CeO 2 exhibit good TDC selectivity. In the end, the electronegativity and catalytic activity of metals are correlated.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2019
·
IF 2.155
Wei Li,Pengcheng Liu,Ruyue Niu,Jinping Li,Shuang Wang
Three CeO 2 supports with different concentration of surface oxygen vacancies were prepared by using C 12 H 29 NO (TPAOH), C 2 H 8 N 2 (EDA) and NaOH as precipitant under hydrothermal conditions, respectively. Catalytic experiments showed that the Ru/CeO 2 -TPAOH catalyst has superior catalytic activity (22000 μmol g −1 h −1 ) than Ru/CeO 2 -EDA (19000 μmol g −1 h −1 ) and Ru/CeO 2 –NaOH (16500 μmol g −1 h −1 ) at 450 °C, 3 MPa. In addition, the introduction of Cs and Ba promoters improve the catalytic activity of the Ru/CeO 2 -TPAOH. However, the introduction of K promoter inhibits the catalytic activity of the Ru/CeO 2 -TPAOH. The 4% Cs promoter can effectively increase the catalytic activity of the Ru/CeO 2 -TPAOH (32000 μmol g −1 h −1 ). BET and TEM indicated that 5.5 nm average pore size of CeO 2 -TPAOH support contributes to the dispersion of active metal Ru. XPS and CO 2 -TPD proved that the Ru/CeO 2 -TPAOH catalyst has higher Ce 3+ concentration, more oxygen vacancies, and higher basic site density, which are important factors for improving ammonia synthesis activity.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Xia Wei,Bing Fang,Tianyao Wang,Hongbin Dai,Song Li
Understanding the metal-support interaction between Rh-B and CeO 2 is essential for enhancing the efficiency of hydrogen generation from hydrous hydrazine. In this study, a series of Rh-B/CeO 2 catalysts were synthesized via a facile wet-chemical reduction method. The Rh-B/(CeO 2 ) 0.7 catalyst exhibits a remarkable 12-fold increase in turnover frequency (TOF) compared to pristine Rh-B catalyst. The strong electronic coupling between Rh-B and CeO 2 was identified as the primary factor driving this significant performance enhancement. This interaction facilitates the formation of oxygen vacancies, promoting hydrazine adsorption and subsequent cleavage of the N-H bond in N 2 H 4 * to form N 2 H 3 *. Our findings emphasize the pivotal role of support engineering in catalyst design for optimizing catalytic performance.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 45
·e202203391
·
IF 2.307
Qun Xiang,Ruiwen Yan,Guiqi Gao,Shuang Wang
Graphical The PANI-CeO 2 @Pt composites with core-shell structure have been successfully synthesized. Platinum nanoparticles were anchored on the surface of the PANI-CeO 2 materials. The lower potential and higher current density for MOR among the tested PANI@Pt, Pt/C, and CeO 2 @Pt catalysts showed that PANI-CeO 2 @Pt catalyst displayed excellent catalytic performance. This work provided a novel approach to prepare anode catalytic materials and had wide application. Polyaniline (PANI) and Pt were synthesized in sequence by in situ electrochemical deposition on CeO 2 surface to prepare PANI/CeO 2 /Pt ternary composites (PANI-CeO 2 @Pt composites). The electrocatalytic activity of PANI-CeO 2 @Pt composite was measured to 226 mA⋅mg −1 , which was 1.7-, 2.3-, 20-flod as that of CeO 2 @Pt, Pt/C, and PANI@Pt catalyst, respectively. The PANI-CeO 2 @Pt catalyst displayed noticeably the highest activity toward methanol oxidation after the 4000 s among the tested CeO 2 @Pt, Pt/C, and PANI@Pt catalyst. In a CO-stripping experiment, PANI-CeO 2 @Pt composites exhibited better CO tolerance. These results meant that highly dispersed Pt nanoparticles and the oxygen storage capacity of PANI-CeO 2 @Pt contributed to admirable catalytic activities for methanol oxidation reaction (MOR).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）