FUEL
·
2018
·
IF 4.908
Yanyan Lei,Wenzhi Li,Qingchuan Liu,Qizhao Lin,Xusheng Zheng,Qifu Huang,Shengnan Guan,Xinhua Wang,Chengxin Wang,Fengyu Li
The catalytic efficiency of CeO 2 carriers and the catalytic properties of palladium (Pd) nanocrystals loaded on different morphology CeO 2 carrier were studied for lean methane (CH 4 ) combustion. The catalytic activity of simple CeO 2 carriers was ranked in the order of rod-CeO 2 (r-CeO 2 ) > cube-CeO 2 (c-CeO 2 ) > octahedral-CeO 2 (o-CeO 2 ). After the Pd species was loaded on CeO 2 , 90% of CH 4 was converted at 348 °C catalyzed by Pd/octahedral-CeO 2 (Pd/o-CeO 2 ) with (1 1 1) crystal faces, which had much higher catalytic activity comparing with Pd loaded on c-CeO 2 with (1 0 0) crystal faces and r-CeO 2 with (1 1 0) and (1 0 0) crystal faces. The results of XRD , HRTEM , EDS , H 2 -TPR, XPS and elemental mapping showed that the Pd species in the form of Pd 0 and PdO were highly dispersed on surface of all CeO 2 carriers. Most importantly, quasi In-situ XPS results convinced that Ce 3+ /Ce 4+ ion pairs played an important role in the catalytic combustion of low-concentration methane by adsorbing or releasing oxygen. Compared with r-CeO 2 and c-CeO 2 , the concentration of Ce 3+ on the surface of o-CeO 2 carrier was greatly increased when the Pd species were present, which indirectly reflected that the concentration of oxygen vacancies on the carrier surface also increased. Consequently, the high catalytic activity of Pd/o-CeO 2 is not only related to the high dispersion of Pd 0 and PdO species on the surface of the catalyst, but also closely related to the synergistic interaction between Pd species and (1 1 1) specific faces of o-CeO 2 exposing.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Yalin Yu,Zhihao Dong,Ling Tan,Nannan He,Rong Tang,Fang Jiang,Huan Chen
Diminishing the size of metal nanostructures can significantly improve the performance of catalysts. However, the self-aggregation of small particles is still an insurmountable obstacle, resulting in the unfavorable stability and recyclability. Herein, we designed and fabricated the Pd-CeO 2-x -NC catalyst though an accurate deposition strategy to downsize the Pd particle to sub-nanometer level and enhance its running stability. The CeO 2-x nanoclusters were firstly dispersed on the nitrogen-doped carbon nanosheets. Further, the active Pd sub-nanoclusters were accurately scattered on the surface of CeO 2-x ascribing to the strong metal-support interaction (SMSI) between Pd and CeO 2-x , which was beneficial to promote the catalytic activity. Subsequently, the high oxidation state Pd n + species were formed due to the electron transfer from Pd to CeO 2-x caused by the SMSI effect. Strikingly, the HER performance of Pd-CeO 2-x -NC was surprisingly correlated with the ratio of Pd n + , suggesting Pd n + acted as the dominant active species. Besides, the SMSI effect stabilized the valence state of active Pd n + species and prevented the sub-nanometer Pd clusters from aggregation, which played a vital role for the enhanced stability of the hybrid catalyst. This synthetic process described here is contributed to prepare various nanostructured catalysts with satisfactory stability through the direct targeting strategy.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Zonggao Hu,Guoli Zhou,Li Xu,Jinghe Yang,Bing Zhang,Xu Xiang
The heterogeneous catalysts based on ternary Pd/CeO 2 -nitrogen-doped graphene (NG) were prepared and utilized for solvent-free aerobic oxidation of benzyl alcohol to benzaldehyde in the presence of green oxidant O 2 . Characterization results revealed that CeO 2 dramatically enhanced the dispersion of Pd nanoparticles, reduced their particle size and inhibited the Pd oxidation formation. With high lattice oxygen storage capability of CeO 2 , excellent electrical conductivity of NG and high catalytic activity of Pd, the ternary catalyst was designed by combining the complementary superiorities of these three components. The ternary composite Pd/5CeO 2 -NG exhibited significantly higher catalytic activity with turnover frequency (TOF) of 30.74 s −1 for solvent-free aerobic oxidation of benzyl alcohol compared with the corresponding binary composites including 5CeO 2 -NG, Pd/NG and Pd/CeO 2 , verifying the synergistic effect among Pd, CeO 2 and NG. The ternary composite was stable and could be recycled up to 6 times without remarkable loss in the activity and selectivity towards benzaldehyde. Owing to its excellent activity, high selectivity, and exceptional stability and recyclability, the Pd/CeO 2 -NG composite has great application potential in the fields of organic synthesis, electrochemical biosensors and fuel cells.
研究领域:
材料科学
·
有机化学
·
催化反应
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Yafu Tang,Yuechao Yang,Dongdong Cheng,Bin Gao,Yongshan Wan,Yuncong C. Li
Soil, air, and water pollution caused by lignite is considered a serious environmental problem. Activation methods thus have been developed to extract humic acid from lignite to support the agricultural production as the soil amendment or fertilizer synergist. The traditional activation methods of humic acid from lignite, however, are not environmentally friendly. As the first study, this work developed a novel solid-phase activation method with a Pd/CeO2 nanocatalyst for lignite-derived humic acid. This study analyzed the morphology and structures of the as-synthesized Pd/CeO2 nanocatalyst with various characterization tools. The mechanisms of the Pd/CeO2 nanocatalyst for lignite activation were determined. The Pd/CeO2 catalyst effectively promoted the production of water-soluble humic acids from lignite via KOH solid-phase activation at room temperature. It increased the amount of small molecular active groups and the corresponding small molecules of humic acid. The existence of a strong synergistic effect at the interface sites between Pd/CeO2 nanoparticles and lignite was one of the key factors for the outstanding catalytic performance. In conclusion, this study has great application perspectives for reducing lignite pollution and increasing humic acid utilization by crops, which can improve the sustainability of the environment and agricultural systems.
研究领域:
环境科学
·
催化化学
·
土壤科学
·
纳米技术
·
农业化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Jinxu Zhang,Fusheng Yang,Tao Fang,Bin Wang,Qingyuan Yang,Zhen Wu,Zaoxiao Zhang
The N-ethylcarbazole/dodecahydro-N-ethylcarbazole system, which offers advantages such as excellent hydrogen storage capacity, good reversibility, and reliable safety, is recognized as a potential candidate for hydrogen storage. However, the inefficient dehydrogenation by existing catalysts limits the commercial application of the system. In this work, CTAB was used as the soft template to increase the specific surface area of CeO 2 supports, and further the active metals were formed upon them through various reduction methods. A series of Pd/CeO 2 catalysts were thus prepared, among which Pd/CeO 2 –C6 adopted a composite strategy of using CTAB as the template to increase the specific surface area of CeO 2 and enhancing the dispersion of Pd through ultrasound assisted reduction, showed the best catalytic dehydrogenation performance for 12H-NEC. After 7 h of reaction at 453 K, the conversion rate of 12H-NEC reached 100 % with 97.24 % of hydrogen released. Combining BET, HRTEM, XPS, CO-pulse chemisorption and other characterization analyses, it was found that the incorporation of CTAB effectively enhanced both the specific surface area and oxygen vacancy concentration of CeO 2 , while ultrasound assisted reduction enabled a small particle size and good dispersion of metal Pd on the support. The strong synergetic effects of support and active metal in Pd/CeO 2 –C6 catalyst largely accounts for its good catalytic performance. This work offers valuable insights and guidance for the development of efficient dehydrogenation catalysts for 12H-NEC.
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
CATALYSIS LETTERS
·
2026
·Vol. 156
·期 7
·191
·
IF 2.5
Liu Yubing,Tang Jie,Cai Chenyu,Gu Runjing,Yang Xinyu,Yue Liang,Bai Yiqiang,Zhang Fengxiao,Liang Jing,Xu Naizhang,Fan Yining
CeO 2 -supported Au and Pd nanocatalyst (Au-Pd/CeO 2 ) was developed and used in the oxidation of 1,2-propanediol (1,2-PDO). Notably, by tuning catalyst composition and reaction conditions, the product selectivity could be well controlled to produce lactic acid (LA) majorly, which was one of the top twelve bio-based platform molecules with very broad application scopes. The catalyst with Pd/(Au + Pd) molar ratio at 0.25 should be the preferable catalyst was screened out to be preferable, affording LA in 92.0% selectivity, while 88.0% of 1,2-PDO was converted under mild reaction conditions (0.3 MPa of O 2 at 80 °C for 3 h). The superior catalytic activities of Au-Pd/CeO 2 probably attributed to the strong interactions between Au and Pd nano particles (NPs), as being reflected by High resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectra (XPS) characterizations. Moreover, strong interactions between Au and Pd NPs making it easy to generate active oxygen species. Superoxide radicals can oxide the first hydroxyl group of 1,2-PDO to carboxyl group, while H 2 O 2 can easy caused C-C bond breaks and generate unwanted by-products. Graphical The alternative text for this image may have been generated using AI.
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-13
·
IF 14.7
Zhang Lina,Wan Shaolong,Du Congcong,Wan Qiang,Pham Hien,Zhao Jiafei,Ding Xingyu,Wei Diye,Zhao Wei,Li Jiwei,Zheng Yanping,Xie Hui,Zhang Hua,Chen Mingshu,Zhang Kelvin H. L.,Wang Shuai,Lin Jingdong,Huang Jianyu,Lin Sen,Wang Yong,Datye Abhaya K.,Wang Ye,Xiong Haifeng
Identification of active sites in catalytic materials is important and helps establish approaches to the precise design of catalysts for achieving high reactivity. Generally, active sites of conventional heterogeneous catalysts can be single atom, nanoparticle or a metal/oxide interface. Herein, we report that metal/oxide reverse interfaces can also be active sites which are created from the coordinated migration of metal and oxide atoms. As an example, a Pd 1 /CeO 2 single-atom catalyst prepared via atom trapping, which is otherwise inactive at 30 °C, is able to completely oxidize formaldehyde after steam treatment. The enhanced reactivity is due to the formation of a Ce 2 O 3 -Pd nanoparticle domain interface, which is generated by the migration of both Ce and Pd atoms on the atom-trapped Pd 1 /CeO 2 catalyst during steam treatment. We show that the generation of metal oxide-metal interfaces can be achieved in other heterogeneous catalysts due to the coordinated mobility of metal and oxide atoms, demonstrating the formation of a new active interface when using metal single-atom material as catalyst precursor.
研究领域:
催化
·
材料科学
·
化学工程
·
表面化学
✓ 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
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Leisheng Che,Jinqiu Guo,Zhiwei He,Hongbo Zhang
We report here that the reduction degree of the metal at the catalytic interface dominates the reactivity of acetylene hydrogenation, mainly in terms of turnover rates (TORs) and activation energies, which could certainly cause the switch of kinetically relevant steps (KRS) from “C 2 H 3 *+H*” over Ce(OH)SO 4 ·xH 2 O dispersed Pd catalyst to “C 2 H 4 *+H*” elementary step over Pd/CeO 2 . Besides, a compact kinetic model has been established to describe the reaction process and the dissociative mechanism was confirmed by H 2 /D 2 exchange experiment. Meanwhile, the rate-determining step (RDS) and the main adsorbed species of the reaction were confirmed by systematic kinetic studies as well as in-situ FTIR analysis. More importantly, with the aid of parity fitting and gas isothermic adsorption analysis, the energetic relationship among the steps along with the acetylene hydrogenation is quantitatively described, which provides a good support and complement for the previous research, and helps researchers build up advanced reaction systems.
研究领域:
化学动力学
·
催化
·
表面化学
✓ 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）