ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2024
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IF 0
You Mengyun,Wu Shufeng,Feng Xiaotong,Zhao Yong,Wang Yubin,Zhang Zhang
The enhancement effect of Ce modification on V 2 O 5 -WO 3 /TiO 2 catalysts at low temperatures was investigated for the selective catalytic reduction (SCR) of NO x with NH 3 (NH 3 -SCR). By adding 9% CeO 2 to 0.5%V 2 O 5 -3%WO 3 /TiO 2 catalyst, the low-temperature denitrification performance of Ce 9 V 0.5 W 3 Ti catalyst after Ce modification was significantly improved, achieving a NO conversion above 90% within a broad temperature range of 200–350℃, with catalytic activity comparable to that of 3% V 2 O 5 -3% WO 3 /TiO 2 . The catalysts were characterized by XPS, H 2 -TPR, NH 3 , and NO-TPD. The results indicated that the Ce additive could enhance the adsorption of NO x on Ce 9 V 0.5 W 3 Ti catalyst due to the synergetic interaction among the Ce and V, W species. The interaction between V and Ce also promoted the formation of V 5+ and Ce 3+ on the surface of the catalyst, which was conducive to enhancing the adsorption and oxidation capacity of the catalyst for NO. Additionally, the introduction of Ce led to a substantial deposition of nitrate species on the surface of the catalyst, especially the increase of nitrite species, which was beneficial to the NH 3 -SCR reaction process, resulting in a significant enhancement of the catalyst’s low-temperature catalytic activity.
研究领域:
环境科学
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催化化学
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产品关联
DOI
PubMed
Waste and Biomass Valorization
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2024
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IF 2.6
Luo Bo,Liu Huiyu,Shan Rui,Zhang Jun,Yuan Haoran,Chen Yong
Purpose This work aims to investigate the thermal behavior and kinetic characteristics of polyethylene (PE) pyrolysis over Cu/Ce modified ZSM-5. The influences of metal types, particles size of active center and interaction of Cu–Ce species on products distribution are elucidated. Methods Metal-modified ZSM-5 catalysts were prepared by negative pressure impregnation method. Catalytic fast pyrolysis and thermogravimetric experiments were conducted using Py–GC/MS and TG/MS for the qualitative and quantitative analysis of pyrolysis products. Results Morphology characterization indicated the interaction of Cu–Ce species facilitated the regulation of active center size into a nanoparticle scale. The final products were restricted to a carbon number of less than 9 over CuCe/ZSM-5. Cu–Ce modification increased the aliphatic content from 58.5 to 76.1%. Kinetic analysis revealed a remarkable reduction in activation energies during both the intermediate and final stages, where an average decrease of 30% was achieved. Conclusion The synergistic effects of Cu 0 and CeO x facilitated the formation of more short chain olefins by enhancing C–C bonds cleavage activity. Undesired polycyclic aromatic hydrocarbons (PAHs) were avoided by the optimal steric hindrance of CuCe/ZSM-5. Graphical Abstract
研究领域:
能源化学
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催化材料科学
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产品关联
DOI
高影响因子
FUEL
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2021
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IF 6.609
Haifeng Li,Tao Liu,Sheng Su,Mei Jin,Wen Fang,Lijun Liu,Yi Wang,Song Hu,Jun Xiang
Ce modified Mn x O y /Al 2 O 3 -La have been prepared to investigate the effect of Ce loadings on pre-breakthrough H 2 S removal efficiency, breakthrough sulfur capacity (BSC) and BSC durability of the sorbents during desulfurization-regeneration cycles. The results showed Ce modification could improve the pre-breakthrough H 2 S removal efficiency of regenerated sorbents during desulfurization-regeneration cycles. The XPS characterization showed that the Ce can promote the binding energy of Mn ion to shift to lower energy, which enhanced H 2 S adsorption on the regenerated sorbent. However, the Ce loading sequence had effect on BSC durability of sorbent during desulfurization-regeneration cycles. The Ce-Mn x O y /Al 2 O 3 -La with co-impregnation of Mn and Ce oxides had higher BSC than Mn x O y /Al 2 O 3 -La, while the Ce/Mn x O y /Al 2 O 3 -La with Ce loading on the surface of Mn x O y /Al 2 O 3 -La had lower BSC and worse BSC durability than Mn x O y /Al 2 O 3 -La. The characterization results showed Ce-Mn x O y /Al 2 O 3 -La obtained better surface area and pore structure than Mn x O y /Al 2 O 3 -La, and Ce ion can promote the increasing of the around electron density of Mn ion, which was beneficial for H 2 S adsorption of Ce-Mn x O y /Al 2 O 3 -La. The poor surface area and pore structure would cause the low BSC of Ce/Mn x O y /Al 2 O 3 -La, and less stability of pore structure might lead to poorer BSC durability of Ce/Mn x O y /Al 2 O 3 -La than Mn x O y /Al 2 O 3 -La during desulfurization-regeneration cycles.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
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2021
·Vol. 52
·期 3
·573-581
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IF 2.8
Zhao Ruiyu,Wang Yi Mou,Li Jie,Meng Wenhua,Yang Chunli,Sun Chongxiang,Lan Xuefang
Ni, Ce, and Ta modified Ti/SnO 2 –Sb 2 O 5 –RuO 2 anodes were first prepared by thermal decomposition strategy and applied for Orange G degradation to explore the effect of Ni, Ce, and Ta modification on electrocatalytic property. The Ta modified anode showed the highest ·OH generation capability and the lowest charge transfer resistance among all samples, conducive to electrocatalytic degradation of Orange G. Besides, the Ta modified anode shows more cracks than Ni and Ce modified anodes, which is expected to create more specific surface areas and more exposed active sites for Orange G degradation. The degradation efficiency and the total organic carbon (TOC) removal rate increased in the order Ru < Ru–Ni < Ru–Ce < Ru–Ta, with Ru–Ta showing the highest degradation efficiency of 98.6% and 44.2%, much higher than 79.6% and 27.5% of Ru, respectively.
Graphical abstract
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Guoqiang Li,Siqi Chai,Guojie Zhang,Jun Liu,Yongfa Zhang,Yongkang Lv,Ying Wang,Yuqiong Zhao
In this paper, Ce-modified Cu-based carbon materials (Cu-Ce/AC) were prepared by impregnation method using walnut shell as the carbon precursor, Cu-ammonia solution as Cu source and Ce as modifier. The catalytic wet air oxidation (CWAO) degradation of phenol wastewater was carried out in a self-assembled fixed-bed reactor. The stability of Cu-Ce/AC catalyst under different pH conditions was studied. This study combines XRD, BET, FT-IR, ICP-OES and XPS characterization techniques to study the main reasons for the deactivation of Cu-Ce/AC catalysts. The reaction mechanism of Cu-Ce/AC catalytic wet air oxidation degradation of phenol was clarified. The result indicates that although phenol was completely converted in the CWAO process, the acidic intermediate product produced were difficult to completely degraded. Therefore, the pH of the solution gradually decreased. In acidic environment, the interaction between active component Cu and carbon carrier is weak, resulting in a large amount of metal leaching into the solution. As a result, the COD conversion gradually decreases. The alkaline environment can effectively slow down the leaching of catalyst Cu while maintaining its high catalytic activity . In addition, the incompletely degraded intermediate products are easy to accumulate and deposit on the Cu-Ce/AC surface, block the micropores and cover the surface-active sites, which reduces the catalyst activity. The study also found that there is a redox cycle between Cu + , Cu 2+ Ce 3+ and Ce 4+ during phenol degradation, which enables Cu and Ce to form a strong interaction. The redox cycle can also promote the formation of oxygen vacancy (h + ), O 2 − ·, and HO·, making the degradation of phenol more thorough. At the same time, the mutual conversion between metal lattice oxygen and surface chemisorbed oxygen can generate high concentration of oxygen defect sites, which can improve the oxygen storage capacity of Cu-Ce/AC. These oxygen vacancies also provide more reactive sites to further promote adsorption and catalytic oxidation degradation of phenol and intermediate products.
研究领域:
环境科学
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催化材料
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2025
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IF 3.5
Lei Chen,Wenjie Yao,Xu Chen,Gang Yang
The Cu-Ce modified SAPO-34/ZSM-5 (S-Z) composite molecular sieve catalysts were synthesized via a stepwise crystallization process using triethylamine (TEA) and tetraethylammonium hydroxide (TEAOH) as dual templates. This method significantly reduces the crystallization time from 24 hours to 12 hours. The incorporation of metal ions alters the structure and acid strength of the molecular sieves, thereby decreasing the rate of coke formation during the reaction, which in turn extends the catalyst's lifetime. Experimental results demonstrated that the catalyst's lifetime increased progressively with the addition of Ce. In the methanol-to-olefin reaction, the catalytic lifetime of the S-Z/Cu 0.05 -Ce 0.05 samples reached 1440 mins, approximately 480 mins longer than that of the S-Z samples, while maintaining a selectivity for low-carbon olefins at around 89.6%.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
Nano Energy
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2020
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IF 16.602
Ligang Chen,Xin Liang,Xiaotong Li,Jiajing Pei,He Lin,Dianzeng Jia,Wenxing Chen,Dingsheng Wang,Yadong Li
The improvement of performance for Pt-based electrocatalysts is of significant importance. Here we synthesized a Ce-modified Pt nanoparticle (NP) with Cerium (III) oxygenated species (1 wt% Ce content) anchored on Pt NPs for methanol oxidation reaction (MOR). High-angle annular dark field-scanning transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray absorption fine structure spectroscopy were combined to prove and analyze this special structure. Surprisingly, the electrocatalytic activity of the Ce-modified Pt NPs for MOR reached 1470 mA/mg -Pt and 8670 mA/mg -Pt in acidic and alkaline media , respectively, which were superior to those of the Pt NPs/C and commercial Pt/C. Density functional calculations showed that the structure of Pt surface was deformed by the modification of Cerium, which made CO* + OH* bind more strongly, and the stronger anchoring of OH* induced the easier removal of CO* in the potential determining step. This work would provide an effective strategy to develop efficient MOR electrocatalysts.
研究领域:
材料科学
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电化学
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催化
✓ 已验证
产品关联
DOI
高影响因子
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