JOURNAL OF SOLID STATE CHEMISTRY
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2020
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IF 2.726
Yafei Guo,Guodong Wang,Xi Yao,Bingqian Liu
Several NiO–CuO–CeO 2 catalysts were prepared via different methods and characterized by different techniques. Structure-activity relationships of the catalysts were demonstrated, and the effect of preparation methods on CO oxidation behaviors was illustrated. Catalytic results evidenced that the NiCuCe-CP and NiCuCe-SG catalysts prepared by co-precipitation and sol-gel methods exhibited better CO oxidation activities and kinetic performance, as evidenced by their lower T 50 values (102 °C and 100 °C) and apparent activation energies (48.80 and 59.28 kJ/mol) as well as higher reaction rates (3.84 and 3.45 μmol/g/s). The XRD and HRTEM results suggested that the active species showed uniform dispersion with minimum crystallite size in the desired catalysts. The XRD, XPS , H 2 -TPR and Raman analysis suggested the formation of Ce 1- x Cu x O 2- δ and Ce 1- x Ni x O 2- δ solid solutions, indicating that the co-precipitation and sol-gel methods reinforced the interactions amongst the ternary metal oxides . This would afford the catalysts more oxygen vacancies for boosted CO oxidation activity. The mechanism was then proposed with the dual synergetic effects in solid solutions for facilitated oxygen mobility and the amorphous active metal oxides for promoted CO chemisorption . The desired NiCuCe-CP and NiCuCe-SG catalysts show potential application for CO abatement in closed-loop air revitalization.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2012
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IF 5.625
Ting Bao,Zhongkui Zhao,Yitao Dai,Xiaoli Lin,Ronghua Jin,Guiru Wang,Turghun Muhammad
CO preferential oxidation (PROX) reactions were performed over the supported Co 3 O 4 -CeO 2 catalysts on modified activated carbon (AC) for eliminating the trace CO from H 2 -rich gases. The effects of support modification by H 2 O 2 oxidation treatment , catalyst calcination temperature, Ce/Co atomic ratio ( n Ce/Co ), Co 3 O 4 -CeO 2 loading and reaction parameters on catalytic properties of the Co 3 O 4 -CeO 2 /AC catalysts were investigated. Various characterization techniques like scanning electron microscopy (SEM), X-ray diffraction (XRD) and H 2 temperature-programmed reduction (H 2 -TPR) were employed to reveal the relationship between catalysts nature and catalytic performance. Results illustrate that the supported Co 3 O 4 -CeO 2 catalyst on modified AC exhibits excellent catalytic properties, which highly depends on dispersity and reducibility of Co 3 O 4 affected by the time of support treatment ( t p ), calcination temperature, n Ce/Co and loading. The supported 35 wt% Co 3 O 4 -CeO 2 catalyst (1:8 of n Ce/Co ) on the modified AC with H 2 O 2 oxidation treatment for 6 h demonstrates the best catalytic properties and the almost complete CO transformation takes place in a wide temperature range of 125–190 °C. Moreover, it is also found that the developed catalyst exhibits an outstanding catalytic stability, and 100% CO conversion can be maintained as the time on stream evolutes up to 1800 min even in the presence of CO 2 and H 2 O in the feed. The optimized Co 3 O 4 -CeO 2 /AC may be a robust and promising catalyst for eliminating trace CO from H 2 -rich gases.
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
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2013
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IF 2.145
Rui-tang Guo,Wen-long Zhen,Wei-guo Pan,Yue Zhou,Jie-nan Hong,Hong-jian Xu,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
CeO 2 –CuO catalyst prepared by citric acid method was investigated for selective catalytic reduction of NO with NH 3 . The activity of the CeO 2 catalyst was enhanced about 8–27% in the temperature range of 125–225 °C at a space velocity of 28,000 h −1 by the addition of Cu. It was found that the state of Cu species had great impact on the SCR performance of CeO 2 –CuO catalyst. Cu 2+ can enhance the low temperature activity of SCR reaction, while CuO would promote NH 3 oxidation before SCR reaction at high temperature, which would cause the decrease of its high temperature SCR activity.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Zhu Peng,Han Chunyang,Xia Haian
Catalytic hydrogenolysis of xylose to ethylene glycol (EG) and 1,2-propanediol (1,2-PG) is an important way for the high-value valorization of biomass. Herein, Ni-W/CeO 2 catalysts prepared by incipient-wetness impregnation method were used for the hydrogenolysis of xylose to EG and 1,2-PG. Several characterizations such as X-ray diffraction (XRD), Transmission electron microscopy (TEM) and X-ray photoelectronic spectroscopy (XPS) were used to analyze the physicochemical properties of the catalysts. The effects of different Ni/W ratios and reaction conditions on the hydrogenolysis performance of the catalyst were investigated. The doping of W promoted the selective cleavage of C–C and C-O bonds of xylose, thus improved the yield of EG 1,2-PG. The doping of W can form interactions with Ni and increase the oxygen vacancy concentration of CeO 2 , which have a significant impact on the catalyst activity. When the Ni: W ratio is around 1:1, the catalyst has the best activity, and the total yield of diols can reach about 43.2%.. When xylan was used as the substrate, the total yield of diols can reach to 58.7%. The possible reaction mechanism of xylose hydrogenolysis was also discussed. This work developed a new catalyst system for the directional conversion of xylose to EG and 1,2-PG, which provided a new idea for the design of catalyst to converting lignocellulose, especially carbohydrate into high-value chemicals. Graphical Abstract Ni-W/CeO 2 with different Ni/W ratio are efficient catalysts for hydrogenolysis of xylose to EG and 1,2-PG.
研究领域:
催化化学
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生物质转化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
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IF 7.139
Hui Wang,Hao Zhu,Yuelan Zhang,Jianglong Pu
A series of CTAB-templated Ni/Ce catalysts were synthesized by adding CTAB during the hydrothermal synthesis of ceria to improve the pore structure of catalysts. Their catalytic performance was evaluated in the steam reforming of acetic acid and the effects of CTAB concentration on the porous structures , reducibilities , morphology, and activity of catalysts were studied. The catalysts were characterized by BET, XRD , H 2 -TPR, XPS , HRTEM , in-situ DRIFTS , DTG , FTIR , and temperature-programmed reaction to elucidate the structure-activity relationship of the catalyst. The results showed that owing to the CTAB assistance, a high surface area of ceria could be achieved, which induced a better Ni dispersion with a smaller Ni size, strengthened the interaction between Ni and CeO 2 , and promoted the reducibility of Ni, obtaining higher activity and lower methane yield than Ni/Ce. Among these prepared samples, Ni/Ce–C6 showed the highest surface area and the best catalytic performance with a hydrogen yield of up to 82.5% even at a low temperature (550 °C). Owing to the stronger Ni-ceria interaction of Ni/Ce–C6, the lattice oxygen in ceria migrates easily to the Ni surface , interacts with the reaction intermediates, and thus improves the CO 2 /CO ratio in the products. Much more CO and CO 2 and less CH 4 were observed over Ni/Ce–C6 during the temperature-programmed reaction, indicating its high activity. In-situ DRFITS characterization demonstrated that the two types of catalysts had similar reaction intermediates but various adsorption and conversion abilities toward the acetic acid. More reaction intermediates were adsorbed at low temperatures and a higher conversion was obtained over Ni/Ce–C6 owing to its better Ni dispersion. The CTAB assistance inhibited the formation of amorphous carbon but facilitated the formation of graphitic carbon at ∼637 °C which did not induce catalyst deactivation .
研究领域:
化学工程
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催化材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
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2022
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IF 6.14
Sainan Cao,Bingjie Zou,Jingxia Yang,Jinjie Wang,Huangdi Feng
A heterogeneous catalyst CuO–CeO2 with a hollow structure was successfully synthesized by assembling CuO on the outer surface of CeO2 hollow spheres through a layer-by-layer deposition strategy. Further reduction under a H2 atmosphere was carried out to modify its surface state, resulting in sample r-CuO–CeO2. The catalysts were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). SEM and TEM showed that the synthesized catalysts had a hollow sphere structure, which can expose more active sites and promote mass transfer. The results of XPS revealed that the content of Cu0&Cu+ increased from 13.6 to 19.0% after H2 reduction, which was conducive to the activation of terminal alkyne to promote the annulation/A3-coupling reaction. The conversion of this cascade reaction with the r-CuO–CeO2 catalyst can reach more than 95%, while the value was only 55% by using CuO–CeO2 as a catalyst. Moreover, the r-CuO–CeO2 catalyst showed a good recycle property and group compatibility in the general applicability of the cascade annulation/A3-coupling reaction, providing a series of propargylamine derivatives in good chemoselectivity.
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
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2017
·Vol. 7
·期 10
·2129-2139
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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
ENERGY & FUELS
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2024
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IF 5.2
Yanbin Zhang,Xifei Yin,Chenghu Zhang,Ying Li,Yinghui Sun,Jie Bai
Dry reforming of methane (DRM) provides an effective method for converting the two main greenhouse gases to hydrogen and carbon monoxide. In this work, Co-CeO2 and CoM-CeO2 (M = Ru, Pd, Pt) catalysts prepared by electrospinning technology were used for DRM. Due to the excellent catalytic performance of Pt itself, the CoPt-CeO2 catalyst had the highest DRM catalytic performance at 850 °C, with a methane (CH4) conversion of 94.12%, and remained stable in 24 h stability testing with almost no carbon deposition. The surface properties of the samples were characterized by Brunauer–Emmett–Teller (BET), temperature programmed reduction with H2 (H2-TPR), temperatureprogrammed desorption of CO2 (CO2-TPD), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicated that part of the reason for the excellent catalytic performance exhibited by adding noble metals to the catalyst is closely related to the high dispersion of active metals. More importantly, the addition of noble metals significantly increased the medium and strong alkaline sites of the catalysts. The abundant oxygen vacancies in CeO2 itself and the increased alkaline sites of noble metals were conducive to the CO2 adsorption and dissociation and the oxidation of deposited carbon. Moreover, the addition of noble metals promoted the interaction between the active metal and support. The results of this study provide a reference for the design of high-performance Co-based DRM catalysts.
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
Molecular Catalysis
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2024
·
IF 3.9
Jiaqi Zhou,Qingrong Wang,Hong Liu,Ming Bao,Jiasheng Wang
Gas-phase selective oxidation of toluene with air is a promising method for producing high-purity benzaldehyde, but the yields of existing catalysts are limited, so the development of more efficient catalysts is of great importance to the chemical industry. Herein VMoNb/CeO 2 was prepared and characterized by SEM, XRD, Raman, XPS, H 2 -TPR, and NH 3 -TPD. The introduction of Mo generated V–O–Mo “asymmetric lattice oxygen” and thus brought high activity. Nb moderated the acidity and oxygen vacancy so as to improve the selectivity. The VMoNb/CeO 2 catalyst showed very high catalytic activity at 500 °C, with 35% toluene conversion and 82% benzaldehyde selectivity at an air flow rate of 30 mL/min for V:Mo:Nb =2:5:0.8. This work could serve as a reference for designing mixed metal oxide catalysts for selective oxidation of aromatic hydrocarbons.
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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Siying Chong,Shuang Zhao,Jiaoyan Li,Gangwei Huang,Yajing Zhang,Ruirui Liu,Kangjun Wang
Gas-phase dehydrocyclization of biomass-derived 1,4-butanediol (BDO) to γ-butyrolactone (GBL) is a sustainable and environmentally friendly process conducted at atmospheric pressure. In the present work, a series of 15Cu/xMgO-yCeO 2 catalysts with different MgO: CeO 2 ratios were prepared by the ammonia vaporization method. The gas-phase dehydrocyclization of BDO to GBL was carried out over these Cu-based catalysts synthesized in a fixed-bed reactor. The physicochemical properties of the catalysts were investigated by XRD, SEM, TEM, FTIR, N 2 isothermal adsorption–desorption, H 2 -TPR, CO 2 -TPD, Raman, XPS, and EPR. The results indicated that the 15Cu/10MgO-90CeO 2 catalyst exhibited a smaller particle size, higher specific surface area, and increased oxygen vacancies than the 15Cu/CeO 2 catalyst. Operating conditions of 240 °C reaction temperature, 2.4 mL/h space velocity, and 98.92 % GBL yield from BDO dehydrogenation were achieved under 40 mL/min N 2 flow for 4 h. Density functional theory (DFT) calculations confirmed that the 15Cu/10MgO-90CeO 2 catalyst with more oxygen vacancies was more favorable for the adsorption and activation of BDO on the catalyst surface than 15Cu/CeO 2 , and its higher catalytic activity was attributed to the synergistic interaction between Cu + and oxygen vacancies on the catalyst surface.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Ziheng Zhen,Antai Li,Youwei Yang,Ying Hu,Jing Lv,Shouying Huang,Yue Wang,Xinbin Ma
Cu/CeO 2 catalysts have been wildly used for the hydrogenation of carbon-oxygen bonds reactions due to their excellent catalytic performance. It is widely accepted that the Cu 0 -Cu σ+ interface could be the primary active sites during the reaction, but how to form and maintain highly dispersed such species remains challenging under the reaction conditions of high temperature and H 2 partial pressure. In this work, we proposed an effective strategy to construct stable Cu 0 -Cu σ+ interface sites over the Cu/CeO 2 catalysts by in situ N 2 O-involved oxidation treatment . It was evidenced that the sequential oxidation-reduction by N 2 O and H 2 broke the grain boundaries of Cu nanoparticles and therefore facilitated the formation of the active Cu 0 -Cu σ+ sites, leading to an enhanced activity. However, a rapid deactivation was observed after this temporary enhancement due to the aggregation of copper species. We further introduced some additional cerium species during catalyst preparation. The 16Cu/CeO 2 -1Ce catalyst prepared by post-impregnation of 1 wt% cerium achieved a stable performance of 90.6% MA conversion after the N 2 O-involved oxidation treatment, which was much higher than that of 26.2% over the 16Cu/CeO 2 catalyst. It was demonstrated that the strong interaction between the formed CeO 2 and reconstructed Cu species prevented the metal sintering and increased the fraction of the Cu 0 -Cu σ+ sites. This method that combined in situ N 2 O-involved oxidation treatment and cerium modification may offer potential in engineering stable active sites for high-performance catalysts in the hydrogenation of carbon-oxygen bonds.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Lijian Wang,Yanqun Zhu,Hui Yang,Yong He,Jun Xia,Yanwei Zhang,Zhihua Wang
The effect of several catalyst supports with large specific surface area (such as SiC, Al 2 O 3 , SiC–Al 2 O 3 –ball, and SiC–Al 2 O 3 ) on catalytic activity was evaluated in this study. CuO–CeO 2 supported on SiC–Al 2 O 3 exhibited high stability and activity, which was considerably close to the thermodynamic equilibrium curve at 625 °C during the stability test for 50 h. The SO 3 decomposition temperature decreased from 750 °C to 625 °C. SiC–Al 2 O 3 contained numerous micropores and mesopores and had a large specific area, indicating strong adsorption, as determined by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption measurement. X-ray photoelectron spectroscopy (XPS) revealed that the surface of SiC–Al 2 O 3 consisted of Al 2 O 3 , SiC, and SiO 2 and that the cerium oxide surface had the largest number of defects. Temperature-programmed reduction (H 2 -TPR) results indicated that the cerium–copper oxides on the surface of powdered SiC–Al 2 O 3 had the strongest redox potential and that CuO had the lowest reduction temperature.
研究领域:
化学工程
·
能源科学
✓ 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）