Nanomaterials
·
2023
·Vol. 13
·期 4
·775
·
IF 5.3
Hong Su,Jiangping Liu,Yanan Hu,Tianhao Ai,Chenhao Gong,Jichang Lu,Yongming Luo
As a representative sulfur-containing volatile organic compounds (S-VOCs), CH3SH has attracted widespread attention due to its adverse environmental and health risks. The performance of Mn-based catalysts and the effect of their crystal structure on the CH3SH catalytic reaction have yet to be systematically investigated. In this paper, two different crystalline phases of tunneled MnO2(α-MnO2and β-MnO2) with the similar nanorod morphology were used to remove CH3SH, and their physicochemical properties were comprehensively studied using high-resolution transmission electron microscope (HRTEM) and electron paramagnetic resonance (EPR), H2-TPR, O2-TPD, Raman, and X-ray photoelectron spectroscopy (XPS) analysis. For the first time, we report that the specific reaction rate for α-MnO2(0.029 mol g−1h−1) was approximately 4.1 times higher than that of β-MnO2(0.007 mol g−1h−1). The as-synthesized α-MnO2exhibited higher CH3SH catalytic activity towards CH3SH than that of β-MnO2, which can be ascribed to the additional oxygen vacancies, stronger surface oxygen migration ability, and better redox properties from α-MnO2. The oxygen vacancies on the catalyst surface provided the main active sites for the chemisorption of CH3SH, and the subsequent electron transfer led to the decomposition of CH3SH. The lattice oxygen on catalysts could be released during the reaction and thus participated in the further oxidation of sulfur-containing species. CH3SSCH3, S0, SO32−, and SO42−were identified as the main products of CH3SH conversion. This work offers a new understanding of the interface interaction mechanism between Mn-based catalysts and S-VOCs.Keywords:CH3SH decomposition;MnO2;oxygen vacancies;oxygen migration
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 10
·1181
·
IF 4.501
Da Song,Yan Lin,Kun Zhao,Zhen Huang,Fang He,Ya Xiong
CO2resourceful utilization contributes to the goal of carbon neutrality. Chemical Looping Dry Reforming (CLDR) has attracted significant attention as a method for converting CO2to CO. NiFe2O4oxygen carrier (OC) is found to be a potential material for CLDR. However, the migration process of lattice oxygen, which are critical for the conversion of CO2to CO, was not extensively investigated. In this study, the reduction and oxidation degrees of the NiFe2O4were finely modulated in a thermogravimetric analyzer. The lattice oxygen migration mechanism of the NiFe2O4in redox cycles was characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and in-situ Raman. The novelty of this paper is clarifying the release-uptake paths of lattice oxygen during CO2resourceful utilization. The result indicates that the concentration gradient between the surface and the bulk drives the diffusion of lattice oxygen. The stabilization of surface lattice oxygen content is attributed to the rapid migration of O anion, which is closely associated with the movement process of Ni particles inward and outward through the spinel bulk. In addition, a highly reactive chemical reaction interface consisting of lattice oxygen and the corresponding metal atoms is always present on the surface of the oxygen carrier and is confirmed by an in-situ Raman and XPS during the whole process of CLDR. The results of this paper offer reference and basis for further development and design of CLDR using spinel OC.Keywords:chemical looping (CL);oxygen carrier (OC);CO2splitting;lattice oxygen;NiFe2O4
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Jiating Shen,Cheng Rao,Ziyang Fu,Xiaohui Feng,Jianjun Liu,Xueliang Fan,Honggen Peng,Xianglan Xu,Chao Tan,Xiang Wang
To gain fundamental understanding on the catalytic property of individual CuO for soot combustion, a series of CuO samples have been prepared with a simple precipitation method by using different Cu precursors and precipitants. Pure monoclinic CuO crystalline phase has been detected by XRD and Raman for all the samples. However, by changing the precursors and precipitants, the morphology and texture property of the CuO samples can be influenced. Furthermore, the redox property of the CuO catalysts can also be altered. Soot-TPR results have testified that four types of active sites with varied activity are present on the surface of all the samples, but only the two types of active sites that can be reduced by soot particles below 500 °C are believed to contribute effectively to soot combustion. It has been discovered that the surface oxygen mobility and abundance are the crucial factors to determine the soot combustion activity of CuO catalysts. Because of the optimal balance of these two factors, CuO-Cu(NO 3 ) 2 -Na 2 CO 3 , a CuO catalyst prepared by the combination of Cu(NO 3 ) 2 precursor and aqueous Na 2 CO 3 precipitant, displays the highest soot combustion activity among all the catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Wenxiang Zhu,Qintao Sun,Mengjie Ma,Fan Liao,Qi Shao,Hui Huang,Kun Feng,Dongdong Gao,Jinxin Chen,Hao Yang,Peiping Yu,Jun Zhong,Tao Cheng,Mingwang Shao,Yang Liu,Zhenhui Kang
Iridium (Ir) - based electrocatalysts, as the benchmark electrocatalysts for oxygen evolution reaction (OER), still suffer from sluggish kinetics and substantial overpotential. Here we show the fabrication of heterophase IrO 2 catalysts with homogeneous distribution of rutile phase on 1 T phase (referred to as m-IrO 2 ) by a simple air-annealing method. In acidic condition, the m-IrO 2 catalyst exhibits high activity with a low overpotential of 170 mV at 10 mA cm −2 and good stability with no sign of deactivation over a prolonged 508-h continuous operation, making it one of the best-performing acid-stable OER catalysts. In this system, H 2 O first forms OH* and O* on the rutile phase, and then the interfacial oxygen migrates from the rutile phase to the 1 T phase. Subsequently, O* drives the OER reaction on the 1 T phase, resulting in the generation of OOH* and eventually the formation of O 2 . The interfacial oxygen migration within the heterophase structure of m-IrO 2 boosts the acidic water oxidation activity significantly. These findings provide a promising design strategy for creating high-activity catalysts suitable for acidic conditions through the manipulation of interfaces.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Rongjiang Zhang,Gen Liu,Cunbao Huo,Jia Liu,Bo Zhang,Bolun Yang,Xiaoyong Tian,Zhiqiang Wu
Perovskite oxygen carriers in a methane chemical looping partial oxidation process enable high reactivity over 850 °C. Lowering the reaction temperature helps to circumvent energy dissipation and couple the above-mentioned process with energy-efficient systems. This paper demonstrates the attractive oxygen-donating capacity of Fe–Ni-based perovskite oxygen carriers for methane partial oxidation. The aforesaid process exhibits more than 70% methane conversion and 6.71 mmol·g–1 unit syngas yield at 700 °C, using LaFe0.5Ni0.5O3. This impressive high reactivity mainly originates from the lowered lattice oxygen bonding strength and the spontaneously constructed active Ni-rich surface of perovskite oxides by Ni doping. In addition to the outward migration of lattice oxygen, active metal elements, such as Ni, continuously segregate to the surface with the reduction of perovskite oxides, promoting methane partial oxidation. We speculate that the chemical looping reaction pathway consists of consecutive competitive reactions based on analysis of the real-time product distribution and the dynamic evolution of oxygen carriers. Highly selective syngas production can be achieved on LaFe0.5Ni0.5O3 by reducing reaction temperatures or increasing space velocity to balance methane dissociation and lattice oxygen release kinetics. Irreversible Ni segregation and phase-separation-induced inert La2O3 on the surface of perovskite oxides during redox cycles are responsible for the cyclic performance degradation of oxygen carriers. This work offers intriguing references to design perovskite oxygen carriers for intensifying the medium-temperature chemical looping partial oxidation process.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Chengrui Wang,Yanhong Fang,Zhenghao Wang,Mujun Long,Dengfu Chen,Huamei Duan,Yandong Li,Guoquan Zhang
Partially oxidizing methane into syngas via a two-step chemical looping scheme was a promising option for methane transformation. Ce 2 (SO 4 ) 3 was selected to explore the performance and mechanism of methane chemical looping partial oxidation (CLPOM) to syngas. Thermodynamic and kinetic analysis forecast the Ce 2 (SO 4 ) 3 as a promising candidate for CLPOM. Compared with literature, Ce 2 (SO 4 ) 3 not only had an outstanding syngas selectivity, but also an appropriate CH 4 conversion and molar ratio, and CH 4 conversion could reach 90.5 % of thermodynamic result. As revealed via characterization, Ce 2 (SO 4 ) 3 (1 0 2) surface had the highest peak intensity and the migration of lattice oxygen played an important role in CLPOM. Some of them were tend to agglomeration and these small particles were less than 5 μm. Density functional theory calculations demonstrated that CH 4 series dehydrogenation products tended to adsorb at O site and CH 3 → CH 2 + H was the rate-determining step. The reaction of surface lattice oxygen atoms and migration of the internal lattice oxygen atoms could inhibit carbon deposition, promote CH 4 conversion and syngas generation in experiment. Compared with NiO, Ce 2 (SO 4 ) 3 had a lower energy barrier of lattice oxygen migration, which could increase the reaction rate.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Yu Kang,Yujia Han,Ming Tian,Chuande Huang,Chaojie Wang,Jian Lin,Baolin Hou,Yang Su,Lin Li,Junhu Wang,Xiaodong Wang
Fe-based oxygen carries (OCs) have attracted wide attention due to the low cost and environmental compatibility for chemical looping methane partial oxidation. However, they usually suffer from low CH 4 reactivity mainly due to insufficient synergy between catalytic CH 4 activation and lattice oxygen mobility. In this work, Fe ions with different amount were incorporated into a novel garnet structure (Y 3 Fe x Al 5-x O 12 ), which exhibited drastically increased CH 4 conversion with reduction time. This resulted from in-situ formed Fe 0 sites at the early stage of reduction, which led to a more efficient reaction route involving methane catalytic decomposition on Fe 0 and the resulted carbon oxidation easier by lattice oxygen, compared with methane directly oxidized by OCs. Moreover, the amount of Fe ions in garnet influenced surface exposed Fe 0 sites and oxygen mobility, inducing Y 3 Fe 2 Al 3 O 12 performed the best with almost 94 % methane conversion thanks to the combined advantages of larger surface exposed Fe 0 and higher lattice oxygen mobility.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Yichuan Wang,Zeyue Wei,Xuanyu Zhang,Weixin Huang
In this paper, a series of heteropoly acids, (Cs 2.2 Cu 0.26 V 0.38 ) x PMo 12 O 40 (x = 1.3, 1.1, 1.0, 0.88), are prepared, characterized and examined as the catalysts for the oxidation of isobutane to MAA. Under the employed reaction condition, Cs 2.23 Cu 0.26 V 0.38 PMo 12 O 40 exhibits an isobutane conversion of 20% and a MAA selectivity of 51% at 335 °C, giving a MAA yield of 0.68 mmol MAA ·h −1 ·g catalyst −1 . Lattice oxygen mobility and acidity of (Cs 2.2 Cu 0.26 V 0.38 ) x PMo 12 O 40 catalysts play key roles. A fast migration rate and a moderate release rate of lattice oxygen are beneficial to the selective oxidation of isobutane to MAA. Cs 2.2 Cu 0.26 V 0.38 PMo 12 O 40 exhibits strong acid sites facilitating MAA desorption and surface sites strongly binding MAA, causing MAA polymerization which blocks the active sites and decreases the long-term catalytic activity. These results demonstrate that the optimization of lattice oxygen mobility and surface acidity is an effective strategy to fabricate efficient heteropoly acid catalysts for the oxidation of isobutane to MAA.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Darong He,Xinmei Ding,Shanshan Li,Yaxin Liu,Ming Zhao,Jianli Wang,Yaoqiang Chen
Deep catalytic removal of nitrogen oxides is one of the widespread research topics, mainly limited by the low temperature activity and hydrothermal stability of the first step for NO oxidation. Oxygen vacancies (O v ) and oxygen migration capacity play a crucial role in this challenge. Particularly, tuning the Mn-O coordination environment according to the radius and valence differences of dopant ions can increase O v , while accelerate oxygen migration by constructing Pt/mullite interfaces. Here, based on the hydrothermal stability of Pt/mullite to NO oxidation, we designed Mg 2+ - and Ba 2+ -doped catalysts. And the NO oxidation performance of the Mg 2+ -doped catalyst was significantly enhanced compared to the undoped catalysts (After hydrothermal aging, turnover frequency = 1.9 s −1 at 150 °C and activation energy = 21 kJ/mol). Meanwhile, all catalysts tested with simulated diesel exhaust and the NO oxidation performance showed essentially no decrease after 16 h of hydrothermal aging at 800 °C. Furthermore, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) demonstrated the O v content of doped catalysts increased significantly. In addition, O 2 temperature programmed desorption (O 2 -TPD) and Thermogravimetry (TG) proved that the oxygen migration capacity of doped catalysts was enhanced by several times. Notably, the simple doping method is general for the modification of other mullites and worthy of industrial application.
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
Energy Technology
·
2019
·Vol. 7
·期 9
·1900374
·
IF 3.163
Zhong Ma,Dewang Zeng,Shuai Zhang,Rui Xiao
NiFe 2 O 4 oxygen carrier (OC) presents higher oxygen carrying capacity than single metal oxides (NiO and Fe 2 O 3 ). However, the redox ability of NiFe 2 O 4 gets deactivated due to phase segregation. Herein, the investigation of the effect of supports (CeO 2 , CeZrO 2 , and ZrO 2 ) on the phase stability and the redox performance of NiFe 2 O 4 during the chemical looping (CL) process are presented. The structure of NiFe 2 O 4 -based OCs is characterized using different characterization methods. The CL reaction is conducted in a fixed-bed reactor at 900 °C under alternate 5% CO/N 2 and 5% O 2 /N 2 atmospheres. The results indicate that the redox performance and the phase stability of NiFe 2 O 4 -based OCs are significantly affected by the supports. According to experimental results, CeO 2 can improve the oxygen mobility of NiFe 2 O 4 . The CeO 2 –NiFe 2 O 4 OC has the best performance in terms of both recyclability and phase stability during the redox cycles. The results show that CeO 2 –NiFe 2 O 4 can reduce the tendency of Fe segregation due to the high concentration of oxygen vacancies. It can be reduced and reoxidized to the original crystalline phase of NiFe 2 O 4 . Nevertheless, the CeZrO 2 –NiFe 2 O 4 and ZrO 2 –NiFe 2 O 4 OCs have drawbacks related to serious sintering and phase segregation into Fe 2 O 3 .
研究领域:
材料科学
·
化学工程
·
能源化学
·
催化化学
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Song Lei,Sisi Wen,Jian Xue,Ao Wang,Jiaqi Li,Zhongyuan Liu,Longgui Zhang,Yifeng Li,Haihui Wang
Insufficient structural stability and limited lattice oxygen mobility at low temperatures seriously limit the application of perovskite-type oxides in mixed ionic-electronic conducting oxygen-permeable membranes. Engineering the crystal structure and oxygen vacancies by ion doping is an effective strategy to enhance both structural stability and lattice oxygen mobility. Different from conventional metal ion doping, we report that the co-doping of the classical SrCoO 3- δ by the non-metallic cation P 5+ and the anion Cl − stabilizes the cubic perovskite structure and allows low temperature oxygen permeation due to improved lattice oxygen mobility. In detail, P doped at the Co site transforms the crystal structure from the hexagonal phase to the cubic phase, and Cl doped at the oxygen site weakens the metal-oxygen bond, which significantly enhances the lattice oxygen mobility. Optimal doping concentrations were found to be SrCo 0 . 95 P 0 . 05 O 3- δ Cl 0.05 (SCP5Cl5). Furthermore, by constructing an asymmetric membrane with a sandwich structure, the oxygen permeation flux of the SCP5Cl5 ceramic membrane was up to 1.10 mL min −1 cm −2 at 873 K, which provides an effective strategy for developing oxygen-permeable membranes with high permeation flux at low temperatures.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jie Fan,Yuhang Sun,Mingli Fu,Jiaqi Li,Daiqi Ye
Metal support interactions modulation is one of the effective strategies to enhance the catalytic performance. Herein, we reported that modulating metal support interactions by switching the strength (CO, H 2 , NH 3 ) and temperature (200, 300, 400 °C) of reducing gases is a facile way to improve the catalytic performance of Pt/CeO 2 for toluene oxidation . The distinct reduction treatments will stepwise enhance the reducibility, ratio of Pt 0 and oxygen vacancy concentration, which dominated the activity. The metal support interactions modulation can significantly affect toluene deep oxidation (from benzoate to formate or monodentate carbonate) via enhancing the mobility of surface/lattice oxygen and activation ability towards O 2 molecules, since the main activation sites for O 2 molecules expand from Pt 0 sites to oxygen vacancies and Pt 0 sites with temperature increasing.
研究领域:
催化化学
·
环境科学
✓ 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）