NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 43
·20777-20785
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IF 3.925
Yanke Yu,Mengqiao Geng,Desheng Wei,Chi He
Selective catalytic oxidation of NH3 (NH3-SCO) is a promising method to reduce NH3 pollution. The Pt-based catalysts exhibited excellent activity in the NH3-SCO reaction under low temperatures. However, it was easy for the NH3 to be oxidized to N2O and NOx (NO and NO2) over the Pt-based catalyst, causing a low N2 selectivity. The CuSO4, which could supply both Brønsted and Lewis acid sites on the catalyst, was used to promote N2 selectivity. The N2 adsorption–desorption, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), inductively coupled plasma mass spectrometry (ICP-MS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), NH3-temperature programmed desorption (NH3-TPD), H2-temperature programmed reduction (H2-TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were used to characterize the catalyst. The addition of CuSO4 could suppress the formation of N2O and NOx, thus the highest N2 selectivity on the catalyst increased from 21.2% to 78.1%. An imide mechanism was the main reaction mechanism on the Pt/TiO2 catalyst. After adding CuSO4, the NH3-SCO reaction over the CuSO4-Pt/TiO2 catalyst mainly followed an i-SCR mechanism where NH3 was oxidized to N2O and NOx, and then the newly formed N2O and NOx were reacted with NH3/NH4+ adsorbed on the Lewis and Brønsted acid sites via an NH3-SCR reaction over the catalyst, and finally N2 was formed. The acid sites performed an important role in the formation of N2 and this work should provide an effective method to promote N2 selectivity in a NH3-SCO reaction.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Chenglin Feng,Xiaolong Liu,Tingyu Zhu,Yutao Hu,Mengkui Tian
Anatase TiO 2 loaded with 0.1wt.% Pt catalyst (0.1Pt/TiO 2 -A) was prepared via the impregnation method, and its CO catalytic oxidation activity was investigated. Noteworthy, introduction of H 2 O into the reaction atmosphere apparently facilitated the catalytic oxidation of CO. Besides, introduction of SO 2 inhibited the catalytic oxidation of CO. In presence of H 2 O and SO 2 , 0.1Pt/TiO 2 -A showed outstanding catalytic stability, and X-ray photoelectron spectroscopy (XPS) and thermogravimetric (TG) characterizations suggested that the amount of sulfate species deposited on the 0.1Pt/TiO 2 -A treated at 230 °C did not increase with time extension, which might be an important reason for the high sulfur resistance of 0.1Pt/TiO 2 -A. XPS results also demonstrated that the dissociation of H 2 O led to considerably increase of hydroxyl groups over the catalyst surface. H 2 18 O isotope-labeling experiments unambiguously showed that C 16 O 18 O was the main product accounting for 88.9%, revealing that the other oxygen atom in the product CO 2 was mostly from H 2 O. Consequently, based on previous researches and our experimental results, the mechanism of H 2 O promoting CO oxidation on 0.1Pt/TiO 2 -A catalyst was proposed.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Wei Chen,Juan Zheng,Yarong Fang,Yutao Wang,Jinpeng Hu,Yuhua Zhu,Xiaoxiao Zhu,Weihao Li,Qian Zhang,Chuanqi Pan,Baojian Zhang,Xiaofeng Qiu,Sibo Wang,Shuang Cui,Jinlong Wang,Jinsong Wu,Zhu Luo,Yanbing Guo
Typically, SO2 unavoidably deactivates catalysts in most heterogeneous catalytic oxidations. However, for Pt-based catalysts, SO2 exhibits an extraordinary boosting effect in propane catalytic oxidation, but the promotive mechanism remains contentious. In this study, an in situ-formed tactful (Pt–S–O)-Ti structure was concluded to be a key factor for Pt/TiO2 catalysts with a substantial SO2 tolerance ability. The experiments and theoretical calculations confirm that the high degree of hybridization and orbital coupling between Pt 5d and S 3p orbitals enable more charge transfer from Pt to S species, thus forming the (Pt–S–O)-Ti structure with the oxygen atom dissociated from the chemisorbed O2 adsorbed on oxygen vacancies. The active oxygen atom in the (Pt–S–O)-Ti active structure is a robust site for C3H8 adsorption, leading to a better C3H8 combustion performance. This work can provide insights into the rational design of chemical bonds for high SO2 tolerance catalysts, thereby improving economic and environmental benefits.
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Xiao Chen,Zhenglong Zhao,Ying Zhou,Qiulian Zhu,Zhiyan Pan,Hanfeng Lu
This study presents an efficient, economic, and simple preparation strategy for Pt/TiO 2 monolith catalysts. Nano-Pt/TiO 2 dispersion liquid with good activity and stability was synthesized by hydrolysis and chemical reduction method. Various Pt/TiO 2 monolithic catalysts were prepared by spraying the dispersion liquid on different substrates. Results of transmission electron microscopy, scanning electron microscopy, N 2 adsorption-desorption, H 2 temperature-programmed and CO oxidation showed that the Pt/TiO 2 nanoparticles with good mesoporous structure and redox properties were highly dispersed on the substrate. The as-prepared 0.5 Pt/TiO 2 cordierite monolithic catalyst with 0.1 wt‰ Pt content exhibited excellent catalytic combustion activity ( T 90 of toluene combustion was 212 ℃), stability (no deactivation was observed during a 120 h test) and firmness (mass loss was 0.11% after 1 h ultrasonic vibration) under experimental conditions. Compared with state-of-the-art methods, this method is more suitable for large-scale production of waste-gas-treated monolith catalysts. And this method meets the concept of energy saving and emission reduction because of its simplicity, high efficiency, environmental friendliness, and high utilization of active components.
研究领域:
环境科学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Riyang Shu,Biqin Lin,Chao Wang,Jingtao Zhang,Zhengdong Cheng,Ying Chen
Noble metal catalyst has an outstanding catalytic activity on the hydrodeoxygenation (HDO) process, but its high cost limits large-scale application. Herein, we put forward a novel photochemical method to prepare the highly dispersed Pt/TiO 2 catalyst with a low metal loading. And it presented an efficient performance on the HDO of phenolic compounds and real bio-oil. Guaiacol could be converted into cyclohexane with 95.1% selectivity at 280 °C under 1 MPa H 2 atmosphere. Characterization results revealed that the high Pt dispersion was the critical factor for the high catalytic activity. And the photochemical method preferred to achieve high metal dispersion due to the room temperature condition. Other typical phenolic monomers and dimers were able to transform into hydrocarbons with most yield above 80%, wherein not only the deoxygenation step, but also the cleavage of ether bonds can be realized in one pot. This catalytic system was also effective on the upgrade of bio-oil derived from the pyrolysis of cotton straw. Hydrocarbon content increased to 33.80% from 11.33%. Alkylphenols content increased to 51.38% from 27.86%. These two products can be used as value-added fuels and chemicals, respectively. Guaiacols and syringols were completely converted into alkylphenols and hydrocarbon. The amount of other oxygenated compounds also decreased significantly. This simple and active catalytic system is potential to apply widely for the upgrade of raw bio-oil.
研究领域:
催化化学
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·
IF 5.627
Fuchang Gao,Zuwei Xu,Haibo Zhao
In this paper, flame spray pyrolysis (FSP) is used to synthesize Pt/TiO 2 catalysts with surface-supported isolated Pt atoms through elaborate precursor/solvent formulation and flame temperature history control. It is a pivotal factor to this FSP process that there is a major distinction on saturated vapor pressure between two components (Pt species and Ti species), and thereby they exist as gas phase and particle phase at a certain temperature range, respectively. When the flame is quenched to ambient temperature with cold sheath gas , Pt species of gaseous PtO 2 (being in the vapor phase above 723 K) condense into deposition state on the surface of TiO 2 nanoparticles . Combined with X-ray photoelectron spectroscopy (XPS) analysis and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) detection, we identify that Pt atoms are dispersed and anchored on the catalyst surface . Single-atom Pt dispersed Pt/TiO 2 catalysts can be well achieved by controlling the loading at a very low level, which offers an effective way to maximize the atom economy for surface catalysis of scarce noble metals. In this work, considering that Pt as the best co-catalyst of hydrogen evolution, the FSP-made Pt/TiO 2 catalysts are tested in a photocatalysis water splitting system aiming to a simple and attractive means of renewable hydrogen production . The highest activity presents in 0.1Pt/TiO 2 with 0.1% molar ratio of Pt to Ti, reaching 108.5 times of the benchmark sample from commercial flame-made TiO 2 (P25). The high activity is attributed to the fact that the isolated Pt atom serves as the main active site for photocatalysis hydrogen evolution. Therefore, the performance and cost efficiency of catalysts are greatly improved by the FSP, mainly ascribed to engineering atomically dispersing Pt on the support surface.
研究领域:
材料科学
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化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2019
·
IF 1.901
Yiqing Zeng,Yanan Wang,Yahan Meng,Fujiao Song,Shule Zhang,Qin Zhong
Herein, we compared the catalyst formation process of three Pt/TiO 2 catalysts prepared by impregnation (PtTi–I), deposition precipitation (PtTi–D) and photo-deposition (PtTi–P) to investigate its effect on oxgyen activation and toluene oxidation activity. The encapsulation of TiO 2 on Pt particles induced by high temperature strengthened the metal–support interaction (MSI) but inhibited the activation of oxygen over PtTi–I catalyst, thus it showed the poorest activity in toluene oxidation. Since the selective deposition of Pt on certain face of TiO 2 during photo-deposition process, PtTi–P exhibited stronger MSI and higher activity although it possessed much larger Pt particles than PtTi–D.
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Lijun Yan,Qing Wang,Wenqiang Qu,Tingting Yan,Hongrui Li,Penglu Wang,Dengsong Zhang
Promoting the ring-opening process is vital to increase the mineralization of aromatic volatile organic compounds. Rational regulation of metal-support interaction is essential for the opening of the aromatic ring over Pt/TiO 2 catalysts. Herein, the Pt/TiO 2 -C catalyst with Ti δ+ -Vo·-Pt δ+ interface obtained by reverse electron transfer is successfully regulated via reduction–oxidation treatment for efficient photocatalytic degradation of toluene. This structure accelerates the pre-activation of toluene to generate abundant reactive intermediate species for the photocatalysis reaction. On the other hand, the special interface endows Pt/TiO 2 -C the ability to produce more reactive oxygen species under illumination, which can synergistically promote the direct opening of benzene ring. The Pt/TiO 2 -C shows a stronger oxidation capacity and a mineralization rate 15% higher than the traditional Pt/TiO 2 . This work proves that reduction–oxidation treatment is an effective approach to modify catalysts for air purification and provides a novel idea for the degradation of other aromatic volatile organic pollutants.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Jinshi Dong,Ting Li,Shengtong Li,Panpan Chang,Qianqian Jin,Jiaqiang Yang,Zhuangzhuang Lai
CO and C3H8, as typical inorganic and organic gaseous pollutants, respectively, require distinct oxidation catalysts for efficient conversion due to their unique properties. In this work, Pt catalysts with different crystal phases of TiO2 (anatase and rutile) as supports were fabricated and investigated for CO oxidation and C3H8 combustion. The surface nature of TiO2 dramatically affects the local environment and electronic properties of supported Pt. Pt-TiO2(R) exhibited superior activity for CO oxidation, whereas Pt-TiO2(A) showed higher reactivity for C3H8 total oxidation. It is concluded that Pt-TiO2(R) contains more oxygen vacancies at the interfacial Pt perimeter sites than Pt-TiO2(A) after reduction pretreatments, which facilitates CO oxidation through the Mars–van Krevelen (MvK) mechanism. The electron-deficient Pt in Pt-TiO2(A) promotes the adsorption and activation of C3H8, and the amount of charge transfer between Pt and adsorbate intermediates during C3H8 oxidation determines the preference of C-C cleavage or dehydrogenation. Lower charge transfer in Pt-TiO2(A) makes C–C cleavage more efficient and contributes to the total oxidation of C3H8. This work emphasizes the importance of engineering material’s local environment and electronic structure to design high-performance oxidation catalysts.
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DOI
高影响因子
Nature Catalysis
·
2020
·Vol. 3
·期 2
·170-178
·
IF 30.471
Huang Zhipeng,Zhao Zhitong,Zhang Chaofeng,Lu Jianmin,Liu Huifang,Luo Nengchao,Zhang Jian,Wang Feng
The decarboxylation of bio-derived fatty acids provides a sustainable pathway for the production of alkane products under mild conditions; however, products are generally obtained in low selectivity due to the uncontrollable reactivity of radical intermediates. Here we demonstrate that photogenerated radicals can be rapidly terminated by surface hydrogen species during photocatalytic decarboxylation of fatty acids on a hydrogen-rich surface that is constructed by the interactions between H 2 and Pt/TiO 2 catalyst, thereby greatly inhibiting oligomerization; C n – 1 alkanes can therefore be obtained from bio-derived C 12 –C 18 fatty acids in high yields (≥90%) under mild conditions (30 °C, H 2 pressure ≤0.2 MPa) and 365 nm light-emitting dode irradiation. Industrial low-value fatty acid mixtures (namely, soybean and tall oil fatty acids) can be transformed into alkane products in high yields (up to 95%). Our research introduces an efficient biomass-upgrading approach that is enabled by subtle control of the radical intermediate conversion on a heterogeneous surface.
研究领域:
化学工程
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催化
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2025
·
IF 5.1
Lu Wang,Siyuan Zhang,Jukun Xiong,Meicheng Wen
Formaldehyde (HCHO), a prevalent indoor volatile organic compound, poses significant health risks to humans even at very low concentrations. As a result, its efficient degradation at room temperature is of utmost importance. However, the detailed mechanism for catalytic oxidation of formaldehyde remains unclear, particularly regarding the role of water vapor, which has been subject to considerable debate. In this study, we synthesized Pt-supported TiO2 glass fiber catalysts (Pt/TiO2 GF) via NaBH4 reduction to investigate the reaction pathways and clarify the influence of water vapor on the oxidation process. The reaction mechanism and intermediates were systematically studied at room temperature using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), kinetic isotope effect (KIE) analysis, and density functional theory (DFT) calculations. Results revealed a clear reaction pathway of HCHO → DOM → HCOO− → CO2, with formate C–H bond cleavage (HCOO−* + O* → CO2 + OH*) identified as the rate-determining step. Both experimental KIE results and theoretical calculations confirmed that water vapor substantially reduces the activation barrier for this step, significantly promoting formate decomposition and subsequent CO2 formation. This work provides critical insights into the role of water in enhancing formaldehyde oxidation and offers theoretical support for developing efficient catalysts suitable for humid environments.
研究领域:
环境化学
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催化
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材料科学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Cangpeng Shan,Qinwei Jia,Yan Zhang,Guoshuai Liu,Xinyu Hou,Yunchong Wang,Rui Han,Caixia Liu,Weichao Wang,Qingling Liu
Removing industrial source CO through catalytic oxidation and providing heat for denitrification units have significant economic and environmental benefits. Sulfur poisoning of catalysts is the bottleneck to stabilize the system operation. To overcome this problem, we fabricated sulfate modified Pt/TiO 2 by appropriate NH 4 HSO 4 deposition, which survived in the SO 2 environment with the concentration as high as 1000 ppm SO 2 , and exhibited an outstanding stability with over 90% CO conversion at 200 °C for 500 h under a typical steel sintering flue gas condition. Experimental and theoretical explorations confirmed that the electronic structure of PtO x clusters was optimized through Pt-O-S bridges after sulfate modification. The O 2p band center closer to the Fermi level and the smaller energy difference between Pt 5d and O 2p band centers led to more active lattice oxygen of PtO x clusters. The more stable π back bonding between Pt 5d and CO 2p and weaker hybridization between Pt and the π⁎ (Ssp2-Osp2)2 orbital of SO 2 indicated enhanced CO adsorption while weakened SO 2 adsorption on Pt sites. The above factors simultaneously improved the low-temperature activity and sulfur resistance for CO oxidation over sulfate modified Pt/TiO 2 . This work provides new insights for the design of sulfur-resistant catalysts and the understanding on the effect of sulfates on catalytic activity.
研究领域:
催化化学
·
环境化学
·
材料科学
·
化学工程
✓ 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）