APPLIED SURFACE SCIENCE
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2022
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IF 7.392
Jing Li,Tongtong Xia,Jiacheng Xu,Chunle Zhang,Li Xu,Zuliang Wu,Shuiliang Yao
CeO 2 /γ-Al 2 O 3 catalysts with distinct crystallite sizes were synthesized by changing the precursors of ceria. CeO 2 /γ-Al 2 O 3 prepared by cerium nitrate (CN) had smaller crystalline size than samples prepared by cerium chloride or cerium acetate. They were evaluated in the plasma catalytic oxidation reaction of n -undecane (C11), which is one of the representative long-chain alkane volatile organic compounds (VOCs). CeO 2 (CN)/γ-Al 2 O 3 displayed a higher C11 conversion of 100 % with 72 % of CO 2 selectivity under ambient conditions with an energy density of 205 J/L, while samples with larger crystalline sizes showed lower activities. X-ray photoelectron spectroscopy analysis confirmed that more concentration of adsorbed oxygen species and higher ratio of Ce 3+ /(Ce 3+ +Ce 4+ ) existed on the surface of CeO 2 /γ-Al 2 O 3 samples with smaller crystalline size. Chemisorption experiments further verified that surface oxygen vacancies resulted in the different catalytic activities. In situ diffuse reflectance infrared Fourier transform spectroscopy analyses showed that the oxidation capability of intermediates by-products enhanced with the decrease of crystalline size. Results revealed that the crystallite size of CeO 2 had a significant effect on the redox properties. This research provides an insight into the regulation of oxygen vacancy in transition metal oxides to facilitate the plasma catalytic performance of alkane VOCs under mild reaction conditions.
研究领域:
催化
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环境科学
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材料科学
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高影响因子
Applied Sciences-Basel
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2022
·Vol. 12
·期 19
·10101
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IF 2.838
Han Gao,Weimin Kong,Shuyuan Zhou,Xuwei Wang,Qingrong He,Yanchun Dong
Chemical warfare agents (CWAs) are highly toxic and fast-acting and are easy to cause large-scale poisoning to humans and livestock after being released. The activated carbon used for CWAs adsorption has disadvantages of limited adsorption capacity, easy aging and deactivation. Metal oxides have environmental stability, and they are characterized by long lasting and broad spectrum when used for thermal catalytic decomposition. Therefore, in this study, the supported copper–cerium catalyst CuO-CeO2/γ-Al2O3was prepared using an equal volume impregnation method. The thermal catalytic decomposition performance was studied using sarin CWAs simulant dimethyl methyl phosphonate (DMMP) as the target compound. The results show that the CuO-CeO2/γ-Al2O3catalyst with a CeO2loading of 5% exhibited better thermal catalytic decomposition performance of DMMP. The catalyst provided protection against DMMP for 237 min at 350 °C; CuO was highly dispersed on CuO-5% CeO2/γ-Al2O3, and there was a strong interaction between Cu and Ce on CuO-5% CeO2/γ-Al2O3, which promoted the generation of surface-adsorbed oxygen, leading to a better thermal catalytic decomposition performance of DMMP. This study is expected to provide a reference for the study of catalysts for the thermal catalytic decomposition of CWAs.Keywords:nerve agent;dimethyl methyl phosphonate;thermocatalytic;CuO;CeO2;γ-Al2O3
研究领域:
环境科学
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化学工程
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高影响因子
CATALYSIS COMMUNICATIONS
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2019
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IF 3.674
Cuncun Zuo,Yun Tian,Yanxia Zheng,Lei Wang,Zhongjun Fu,Tiantian Jiao,Ming Wang,Haofei Huang,Yuchao Li
Series of gold and ceria supported γ-Al 2 O 3 catalysts were developed for the oxidative esterification of methacrolein with methanol. All the catalysts were prepared through one step deposition-precipitation method, and K 2 CO 3 and urea were used as precipitant, respectively. Au, CeO 2 and γ-Al 2 O 3 could self-assemble unique particle morphology during co-precipitation process and form semi-core shell or core shell structure after calcination . The relationship between catalytic reactivity and structural characteristics were analyzed by SEM, TEM, EDS, BET, XRD, XPS, etc. Among Au-CeO 2 /γ-Al 2 O 3 (K 2 CO 3 ), Au-Ce/γ-Al 2 O 3 (Urea) and Au/γ-Al 2 O 3 (Urea) catalysts with different active components and precipitant, the last two exhibited higher catalytic activity. Moreover, the Ce-doped catalysts shown higher stability than just Au supported on pure alumina. The active stability of the optimum Au-Ce/γ-Al 2 O 3 catalyst was evaluated with seven-time cyclic reactions exhibiting high stability and activity with the yield of MMA above 90%.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2026
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IF 17.2
Run Pan,Abubakar Yusuf,Chengjun Wang,Jianrong Li,Zhiyu Xiao,Shuai Liu,Yidong Zhong,Yong Ren,Zheng Wang,Hainam Do,John L. Zhou,George Zheng Chen,Jun He
Natural gas vehicles (NGVs) offer significant environmental advantages by reducing pollutant emissions, but effective exhaust treatment remains a challenge due to high methane emissions and catalyst deactivation over time. This study introduces a core-shell Pd@CeO 2 /Al 2 O 3 three-way catalyst (TWC) designed to enhance the efficiency and durability of NGV exhaust treatment. The core-shell structure significantly improves catalytic performance. The optimized Pd@Ce/Al (S-500) catalyst demonstrates excellent low-temperature activity, with T 50 values of 336 °C for CH 4 and 397 °C for NO. It also achieves remarkable reductions of 113 and 177 °C in the T 90 for CH 4 and NO conversion, respectively, compared to the non-core-shell counterpart, Pd-Ce/Al (S-500). Characterizations reveal enhanced metal-support interactions, increased oxygen vacancies, and optimized Pd-CeO 2 interfaces as key active sites. Density functional theory calculations further demonstrate that the core-shell structure facilitates electron transfer at Pd-CeO 2 interfaces and lowers energy barriers for three-way reactions, enhancing catalytic efficiency. Notably, the core-shell Pd@Ce/Al (S-500) catalyst maintains high conversion efficiency for CH 4 and NO, with only slight losses (5.5% and 6.6%, respectively) over a 100-h time-on-stream stability test, following 16 h of harsh hydrothermal aging at 800 °C, showcasing its long-term stability. These findings provide a deeper understanding of the role of the core-shell Pd@CeO 2 structure in Pd-based TWCs and offer valuable insights for designing durable and efficient catalysts to meet the stringent emission standards of NGVs.
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高影响因子
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