CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Shuaishuai Lu,Jingde Zhang,Yuanyuan Sun,Huichao Liu
CuO-CeO 2 -ZrO 2 /cordierite catalysts have been successfully prepared by the impregnation reduction method. The effects of processing parameters such as the condition of reduction process, calcination temperature, the addition of surfactant on the size and shape of catalyst particles were studied by X-ray diffraction (XRD), BET surface area measurements, and scanning electron microscopy (SEM). The catalytic performance of the as-prepared catalysts for CO oxidation were evaluated by using a microreactor-GC system. The results indicate that the processing parameters influence greatly the size and shape of catalyst particles. Fragmental shape catalysts were formed when the impregnated samples were reduced in the thermostat water bath. However, spherical-like particles were obtained by ultrasonic-assisted in the reduction process. Tiny flower-like catalyst particles were found when the surfactant were used. When the calcination temperature decreased, the grain size of catalysts has reduced, and the catalytic activity for CO oxidation has been improved. The introduction of ultrasonic and surfactant resulted in larger specific surface area and better catalytic performance.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2017
·
IF 2.594
Zhaopeng Liu,Yan Xu,Zhenhua Li,Baowei Wang,Weihan Wang,Xinbin Ma,Renjie Liu
In this paper, Ce 0.2 Zr 0.8 O 2 composite supports were prepared by different Ce-addition methods including impregnation of cerium (CeZr-imp), impregnation of citric acid and cerium (CeZr-CA) simultaneously and deposition precipitation method (CeZr-DP), respectively. The as-prepared supports were applied to prepare 10 wt% MoO 3 /Ce 0.2 Zr 0.8 O 2 catalysts for sulfur-resistant methanation . The N 2 adsorption/desorption, X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron (XPS), temperature-programmed reduction by hydrogen (H 2 -TPR) were undertaken to get textural properties, morphological information and structures of the catalysts. The results showed that MoO 3 was highly dispersed on the surface of these three supports and Ce was mostly of coexisted in Ce 4+ /Ce 3+ redox pairs. Compared with Mo/CeZr-imp, the CO conversion increased by 10% and 15% for Mo/CeZr-CA and Mo/CeZr-DP, respectively. This was mainly attributed to the larger specific surface area, Ce 3+ concentration and content of active MoS 2 on the surface of catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
·
IF 3.131
Gang Yu,Kuo Han,Jing Wang,Xiao Cheng,Hongmei Ma,Hongya Wu,Zhigang Yang,Guanglei Zhang
In the present work, the activated carbon fibers (ACFs) with homogenous and crystalline CeO 2 -ZrO 2 coatings were obtained using a facile water steam treatment process at a low temperature (300 °C) for efficient removal of Pb(II) from aqueous solutions. The morphology, surface chemical states, and adsorption performance were studied extensively. Results demonstrated that the steam-treated CeO 2 -ZrO 2 /ACFs possessed superior high surface areas (783.23 m 2 g −1 ) and pore volumes (0.41 cm 3 g −1 ). Moreover, numerous C-O-M bonds formed in the interface between CeO 2 -ZrO 2 coatings and ACFs, which can endow the adsorbent desired mechanical property and service durability as well as many surface hydroxyl groups were found and adsorption capacity (61.54 mg g −1 at pH 6.5 ± 0.3 and 25 °C). It was suggested that the steam-treated CeO 2 -ZrO 2 /ACFs could be considered as a promising adsorbent towards wastewater treatment .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 5
·052507
·
IF 4.316
Qingchun Wang,Zihao Wang,Xiaolong Liang,Shengli An,Changkun Cai,Yuanyuan Liu,Jinxiao Bao,Xiwen Song
Spherical CeO2 and CeO2-ZrO2 solid solutions are prepared using a hydrothermal method, Pt/CeO2-ZrO2/GO and Pt-CeO2/GO catalysts are prepared using graphene as a carrier, and the effects of the addition of a CeO2-ZrO2 solid solution on the electrocatalytic activity, stability and anti-CO poisoning performance of methanol fuel cell anodes are investigated. The catalyst samples are characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the electrochemical properties of the catalysts are investigated using an electrochemical workstation (IVIUM). The results show that Pt/CeO2-ZrO2/GO has a higher electrocatalytic activity and stability against CO oxidation than Pt-CeO2/GO, Pt/GO and commercial Pt/C catalysts, which is attributed to ZrO2. When Zr4+ is added into the CeO2 lattice, the activity of oxygen in the CeO2 lattice, the oxygen mobility and the oxygen vacancies are increased, the oxygen storage capacity is improved, and the intermediate product of CO is more easily oxidized. This finding indicates that Pt/CeO2-ZrO2/GO is a methanol oxidation anode catalyst with a good catalytic activity, stability and resistance to CO poisoning.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2018
·Vol. 20
·期 6
·1-13
·
IF 2.127
Yang Runnong,Liu Yumei,Yu Lin,Zhao Xiangyun,Yang Xiaobo,Sun Ming,Luo Junyin,Fan Qun,Xiao Jianming,Zhao Yuzhong
A simple hydrothermal procedure is introduced, which leads to the successful synthesis of a new composite material with fine CeO 2 -ZrO 2 nanocrystallites embedded in amorphous and porous SiO 2 matrices. The composite material possesses an extraordinary high thermal stability. After being calcined at 1000 °C, it retains CeO 2 -ZrO 2 nanocrystallites of the size around 5 nm, a BET-specific surface area of 165 m 2 /g, and an oxygen storage capacity of 468 μmol/g. No phase segregation for CeO 2 -ZrO 2 nanocrystallites is detected and the SiO 2 matrices remain not crystallized. The composite material shows a great potential as a support of three-way catalyst, as evidenced in catalytic tests with supported Pt.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
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2014
·
IF 6.007
Fredrik Gunnarsson,Moa Z. Granlund,Mattias Englund,Jazaer Dawody,Lars J. Pettersson,Hanna Härelind
We report on a high NO x reduction activity over Ag/Al 2 O 3 catalysts, using hydrogen produced in a fuel reformer. The focus of the study is to evaluate the performance of a hydrocarbon selective catalytic reduction (HC-SCR) catalyst in real conditions. Initially, the catalytic materials for the fuel reformer (Rh/CeO 2 -ZrO 2 ) and the HC-SCR (Ag/Al 2 O 3 ) were evaluated in separate bench-scale reactor setups. These two setups were subsequently joined into an integrated bench-scale reactor setup with the aim to evaluate the influence of the reformate on the HC-SCR activity in a controlled environment. In the final phase of the study a 4 wt.% Ag/Al 2 O 3 catalyst doped with 100 ppm(w) Pt was scaled up and tested in a pilot-scale reactor setup. The pilot-scale reactor setup enabled evaluation of the HC-SCR activity in real exhaust gases generated by a single cylinder engine (genset) together with a hydrogen-rich gas supplied from a fuel reformer. Commercial biodiesel (NExBTL) was used as reducing agent for the HC-SCR as well as fuel in the fuel reformer for both the bench-scale and pilot-scale experiments. This study gives an excellent link between evaluations of the catalytic materials, controlled bench-scale experiments and applied engine experiments, proving a viable concept for lean NO x reduction together with onboard hydrogen production. A NO x conversion of above 70% was reached at temperatures below 250 °C, in bench-scale experiments when hydrogen produced in the fuel reformer is added.
研究领域:
环境科学
·
催化化学
·
能源工程
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2015
·
IF 2.79
Yane Zheng,Kongzhai Li,Hua Wang,Xing Zhu,Yonggang Wei,Min Zheng,Yuhao Wang
Chemical-looping reforming of methane (CLRM) offers a potentially effective approach for the coproduction of syngas and pure hydrogen. Macroporous CeO2–ZrO2 solid solutions with different pore sizes were prepared as oxygen carriers for the CLRM system. The physical and chemical properties of the oxygen carriers were characterized by the techniques of scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), X-ray powder diffraction (XRD), N2 adsorption–desorption, Raman spectra, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), and temperature-programmed oxidation (TPO). The relationship among the structural features, the concentration of oxygen defect, and the oxygen mobility of the macroporous CeO2–ZrO2 solid solutions and the nonporous sample were also discussed. It is found that the specific surface area and oxygen mobility of such oxides are closed correlated to their performance for the CLRM process. Compared with the nonporous sample, the macroporous CeO2–ZrO2 solid solutions own lower specific surface area and better oxygen mobility due to the relatively high concentration of the oxygen vacancy. This allows such oxides to own both high conversion and selectivity for the oxidation of methane to syngas using a chemical-looping concept. The presence of the macroporous structure also improves the reoxidation rate and hydrogen yield (the hydrogen yield increased by 50%) in the water splitting step. This can be attributed to the abundant channels in the materials, which may improve the dynamic conditions of the gas–solid reactions, resulting in relatively high utilization rate of oxygen carriers. The pore size also affects the activity of the macroporous oxygen carriers. The increase of the pore size slightly reduces the reactivity of the oxygen carrier due to partial collapse of the macroporous structure. The macroporous Ce–Zr-100 oxygen carrier with a pore size of 100 nm exhibits excellent activity and stability in the coproduction of pure hydrogen and high-quality syngas, even after 40 times successive redox cycles.
研究领域:
能源材料学
·
催化化学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xiaodi Li,Shan Ren,Lian Liu,Xiangdong Xing,Lin Chen,Jiangling Li,Jian Yang,Qingcai Liu
The serious deactivation of denitration catalysts caused by heavy metals still a thorny issue in the practical application of selective catalytic reduction of NO x with NH 3 . Herein, we proposed a novel anti-poisoning strategy by designing SO 4 2− /ZrO 2 superacid supported CeO 2 /ZrO 2 catalyst, and the effect of SO 4 2− /ZrO 2 supported CeO 2 /ZrO 2 for PbO-resistance NO x catalytic reduction was investigated. It was worthy to note that the introduction of solid superacid SO 4 2− /ZrO 2 significantly enhanced catalytic performance over the entire temperature range, with an exceptionally high NO x removal efficiency over 98 % during 250–500 °C. When 2 wt% PbO was deposited on the fresh catalyst, the catalytic activity of CeO 2 /ZrO 2 catalyst decreased obviously, while CeO 2 /ZrO 2 -S catalyst can still maintain a higher NO x conversion over 90 % from 275 to 500 °C. The characterization results confirmed that the introduction of solid superacid SO 4 2− /ZrO 2 enhanced the surface acidity and promoted the transformation from Ce 4+ to Ce 3+ . The results of in situ DRIFTS implied that the Eley-Rideal (E-R) mechanism was obeyed over CeO 2 /ZrO 2 catalyst, and both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms were followed over CeO 2 /ZrO 2 -S catalyst in the SCR process. With regard to poisoned catalysts, the NH 3 adsorption was inhibited to some extent, while the reaction mechanism wasn’t changed by PbO poisoning.
研究领域:
催化
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 28
·e202301088
·
IF 2.1
Hui Zhou,Xiaoliang Sun,Wenming Guo,Tingting Bao,Yi Zhang,Chenxu Guo,Hanning Xiao,Hang Qin,Pengzhao Gao
Graphical [+] These authors contributed equally to this articleDurable CuO/ZnO/CeO 2 /ZrO 2 catalyst on SiC support for methanol steam reforming was prepared by the combination of inverse microemulsion method and precipitation method. The methanol conversion of the catalyst was still reached 98.8 % after 150 h, considerably higher than that of solution combustion method (70 %), without carbon deposition and pronounced sintering after the reaction. Durable CuO/ZnO/CeO 2 /ZrO 2 catalyst on SiC support for methanol steam reforming (MSR) was prepared by the combination of inverse microemulsion method and precipitation method which is termed as inverse microemulsion/precipitation method. The presence of Ce−O−Zr solid solution facilitated the production of oxygen vacancies and Ce 3+ species in the prepared CuO/ZnO/CeO 2 /ZrO 2 catalyst. Owing to the unique tiny reaction pool and the addition of precipitant for inverse microemulsion/precipitation method, the particle size of the prepared catalyst was principally between 2 and 6 nm, with an average size of 3.66 nm. Besides, the small particle size and the highly dispersed of Cu species boosted the reduction performance of the catalyst, enabling the reduction temperature to be only 201 °C. The methanol conversion of the reduced catalyst was still reached 98.8 % after 150 h, considerably higher than that of solution combustion method (70 %), without carbon deposition and pronounced sintering after MSR reaction.
研究领域:
催化化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE IONICS
·
2016
·
IF 2.38
Jiang Tan,Yuchang Su,Te Hu,Qiushan Yu,Rabigul Tursun,Quan Li,Yunze Xi
The cubic 10Sc1CeSZ (10 mol% Sc 2 O 3 –1 mol% CeO 2 –89 mol% ZrO 2 ) was prepared by controlling the concentration of the urea varied from 0.4 to 0.6 mol/L in the hydrothermal process. XRD results depict that the 10Sc1CeSZ blocks have a stable cubic phase structure at room temperature after sintering at 1150–1450 °C. SEM characterization of the fracture surface of the 10Sc1CeSZ blocks shows that the grain size increases from 0.3 to 8 μm during heat treatment up to 1150–1450 °C, correspondingly, the relative densities increase from 98.3% to 99.7%. The impedance spectra measured at 300 °C reveal that the grain boundary resistance reduces with the increase of sintering temperature . Impedance analysis results show that the 10Sc1CeSZ block sintered at 1450 °C for 4 h has the highest total ionic conductivity of 0.137 S cm − 1 at 800 °C.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Dewen Sima,Haojin Wu,Koukou Tian,Shijun Xie,Joel Jie Foo,Shuirong Li,Duo Wang,Yueyuan Ye,Zhifeng Zheng,Yun-Quan Liu
Ammonia decomposition is an effective way for high purity hydrogen production , yet the increase of catalytic activity at low temperatures remains a big challenge for this process. In this paper, a CeO 2 –ZrO 2 composite with Al as the secondary dopant was synthesized by the co-precipitation method, which was used as the carrier of nickel metal for ammonia decomposition. The experimental results showed that an obvious increase in catalytic activity of the ammonia decomposition at the relatively low temperature range of 450–550 °C was achieved over the nickel catalyst with CeO 2 –ZrO 2 composite as the metal carrier. Specifically, the complete decomposition of ammonia was achieved at 580 °C for Ni/Al–Ce 0.8 Zr 0.2 O 2 catalyst, while only 92% of ammonia was decomposed at 600 °C over the reference Ni/Al 2 O 3 catalyst. The characterization results indicated that the introduction of Al as the secondary dopant of ceria not only increases the specific surface area and oxygen defects on the surface, but also enhances the nickel metal dispersion and metal-support interaction, thus enhances the catalytic performance of Ni/Al–Ce 0.8 Zr 0.2 O 2 catalyst in the ammonia decomposition.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 4
·668
·
IF 5.719
Qingyun Li,Lingyu Liu,Zihua Wang,Xuezhong Wang
A confined jet mixing reactor operated in continuous hydrothermal flow synthesis was investigated for the synthesis of CeO2-ZrO2(CZ) nanoparticles. The obtained ultrafine powders were characterized using scanning electron microscopy–energy dispersive spectrometry (SEM-EDS), inductively coupled plasma–atomic emission spectroscopy (ICP-AES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED), a BET (Brunauer-Emmett-Teller)-specific surface area test and pore analysis, oxygen storage capacity (OSC) test, and a H2temperature programmed reduction (H2-TPR) test. The XRD results show that all samples were composed of high-purity cubic CZ nanoparticles. High resolution transmission electron microscope (HR-TEM) analysis showed that CZ nanoparticles with uniform size and shape distributions were obtained in this investigation. The d-spacing values, determined based on the TEM-selected area electron diffraction (SAED) patterns, were in good agreements with the reference data. BET results showed that the prepared CZ samples had large specific surface areas. Pore volume and size distribution were obtained by pore analysis. Oxygen pulse adsorption technology was used to test the oxygen storage capacity of the sample. The redox capacity of the CZ material was determined by a H2temperature-programmed reduction test.Keywords:continuous hydrothermal flow synthesis;confined jet mixing reactor;CeO2-ZrO2nanoparticles;XRD;BET
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）