Frontiers of Chemical Science and Engineering
·
2017
·Vol. 11
·期 4
·586-593
·
IF 1.712
Liu Huan,Ma Zhen
Hexagonal CePO 4 nanorods were prepared by a precipitation method and hexagonal CePO 4 nanowires were prepared by hydrothermal synthesis at 150 °C. Rh (NO 3 ) 3 was then used as a precursor for the impregnation of Rh 2 O 3 onto these CePO 4 materials. The Rh 2 O 3 supported on the CePO 4 nanowires was much more active for the catalytic decomposition of N 2 O than the Rh 2 O 3 supported on CePO 4 nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO 2 , O 2 , H 2 O or O 2 /H 2 O) on the N 2 O decomposition was also investigated. The samples were characterized by N 2 adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO 2 temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2022
·
IF 3.656
Lei Ma,Feifei Zhang,Kunjie Li,Yingying Zhang,Zhiqiang Song,Li Wang,Jiangfeng Yang,Jinping Li
The capture of N 2 O from CO 2 by an adsorption-based mechanism remains a significant challenge due to their similar molecular sizes and physical properties. Although substituent engineering has been widely employed for the selectivity regulation and improvement of gas mixtures in metal-organic frameworks, its effect on N 2 O/CO 2 separation has yet not been explored. Herein, four isoreticular MTN-type metal-organic frameworks (MOFs) with different substituents (-H, –NH 2 , -Br or –NO 2 ) are reported for the capture of N 2 O from a N 2 O/CO 2 mixture. As revealed by isothermal measurements, thermodynamic studies and ideal adsorbed solution theory computations, the N 2 O/CO 2 separation potential can be effectively improved by an electron-donating group (-NH 2 ), whereas electron-withdrawing groups (-NO 2 or -Br) exhibit the opposite effect. Notably, MIL-101(Cr)–NH 2 exhibits, by far, the highest ideal adsorbed solution theory equilibrium adsorption selectivity of 1.91 for 50/50 N 2 O/CO 2 . The N 2 O/N 2 separation ability of the modified materials is also studied and functionalization with a -Br group yields an improved separation potential compared to the parent MIL-101(Cr) material. The strategy of using substituents to enhance the N 2 O/CO 2 separation efficiency of MOFs could also be extended to other porous materials for chemical separation processes.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Chuande Huang,Yanyan Zhu,Xiaodong Wang,Xin Liu,Junhu Wang,Tao Zhang
A series of BaFe 1− x Sn x O 3− δ catalysts were prepared by sol-gel method and tested for N 2 O decomposition to shed light on the effect of B-site substitution on the catalytic behavior of perovskite catalysts. 119 Sn and 57 Fe Mössbauer results confirmed that the 5-fold coordinated Fe 3+ cations with one adjacent oxygen vacancy (Fe 3+ O 5 ) were the main active centers for N 2 O decomposition. Doping of Sn cations can significantly improve the percentage of Fe 3+ O 5 from 30% ( x = 0) to 68% ( x = 0.8). More importantly, the valence state of Fe could be gradually reduced due to weakening of Fe O bond with increasing the Sn content, which was attributed to the stronger force of Sn than Fe in Fe O Sn structure to draw the oxygen anion and expansion of unit cell volume. Such change of Fe chemical state favored the oxygen mobility of the catalyst, leading to reduction in activation energy for N 2 O decomposition from ca. 241 ( x = 0) to 178 kJ mol −1 ( x = 0.8). BaFe 0.2 Sn 0.8 O 3− δ catalyst exhibited the highest intrinsic rate of 1.49 s −1 (550 °C), nearly 4 times larger than that of BaFeO 3− δ (0.43 s −1 ).
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Li Wang,Zhangmiao Ye,Caihong Lin,Yugao Wang,Jinping Li,Jiangfeng Yang
N2O/CO2 separation in the tail gas of adipic acid presents a significant challenge due to the closely resembling physical characteristics exhibited by CO2 and N2O. Herein, adsorption and separation performances of CO2 and N2O on FAU-type zeolite Y with different cations (Na+ and Ag+) were studied comprehensively. After Ag+ exchange, zeolite Y changes from a CO2-selective adsorbent to a N2O-selective adsorbent. AgY shows high N2O uptake (95.7 cm3/g) but relatively low adsorption heat (23.1 kJ/mol), making it suitable for N2O/CO2 separation. In situ Fourier transform infrared spectrometry indicates that N2O is successfully adsorbed on AgY. The breakthrough experiment reveals that AgY exhibits superior performance in the separation of N2O/CO2 at a flow rate of 20 mL/min while also exhibiting a favorable retention time and ratio of retention time with CO2 breakthrough time, which can reach up to 4.1 min and 0.24, respectively, which makes it an optimum N2O/CO2 separation material reported so far.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2024
·
IF 3.8
Yuxin Sun,Yunshuo Wu,Zhuoyi Zhang,Xuanhao Wu,Haiqiang Wang,Zhongbiao Wu
Graphical Ce-Pr co-doped Co 3 O 4 achieved 100% N 2 O conversion at 400 °C over Pr 0.02 Ce 0.2 Co 1 . The introduction of Ce facilitated the formation of oxygen vacancies, which were essential for N 2 O activation. But these Ce species strictly inhibited Co 3 O 4 crystallization and surface exposure, which were unfavorable to N 2 O decomposition. By the codoping of Pr, these negative effects were eliminated, leading to remarkable catalytic performance. Nitrous oxide (N 2 O) has gained increasing attention as a non-carbon dioxide greenhouse gas, and catalytic decomposition is an effective method for mitigating its emissions. In this study, Ce-Pr Co-doped Co 3 O 4 was synthesized via a coprecipitation method and used for the catalytic decomposition of N 2 O. The experimental results revealed that the N 2 O decomposition achieved 100% conversion at 400 °C on the catalyst with a Pr/Ce/Co molar ratio of 0.02:0.2:1, exhibiting an 80 °C decrease of T 100 compared with that of Co 3 O 4 . The introduction of Ce reduced the size and crystallization of Co 3 O 4 particles, increased the activity of the lattice oxygen of Co 3 O 4 , and facilitated the formation of oxygen vacancies, thereby enhancing the activation of N 2 O. However, the introduction of Ce inhibited the crystallization of Co 3 O 4 and the surface coverage of CeO 2 decreased the exposure degree of N 2 O molecules to the Co 3 O 4 surface. Co-doping strategy of Ce-Pr was performed to alleviate the negative effects of ceria. Consequently, the incorporation of Ce and Pr species enhanced the redox properties of Co 3 O 4 , leading to remarkable catalytic performance of N 2 O decomposition. This study elucidated the interaction between Ce and Pr dopants and Co 3 O 4 , and encouraged more attention on designing novel catalysts for N 2 O mitigation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Huan Liu,Zhen Ma
LaPO 4 has been used as a support to make supported catalysts in some investigations, but the effect of different LaPO 4 supports on the catalytic performance of supported catalysts has been rarely reported. In this work, conventional hexagonal LaPO 4 (LaPO 4 H) was prepared by precipitation, and hexagonal LaPO 4 nanowires (LaPO 4 HNW) was prepared by hydrothermal synthesis at 150 °C. Monoclinic LaPO 4 nanowires (LaPO 4 -MNW-220 and LaPO 4 -MNW-900) were prepared by hydrothermal synthesis at 220 °C or calcining LaPO 4 HNW at 900 °C. These samples were used to support Rh 2 O 3 via impregnation using Rh(NO 3 ) 3 as a precursor. The activities of these supported catalysts in N 2 O decomposition and CO oxidation follow the same sequence of Rh 2 O 3 / LaPO 4 HNW > Rh 2 O 3 / LaPO 4 H > Rh 2 O 3 / LaPO 4 -MNW-220 > Rh 2 O 3 / LaPO 4 -MNW-900, i.e. , two hexagonal LaPO 4 supports are better than two monoclinic LaPO 4 supports in making active catalysts, and hexagonal LaPO 4 nanowires are better than hexagonal LaPO 4 composed of nanoparticles and short nanorods. The most active catalyst has highly dispersed Rh 2 O 3 species interacting strongly with the support, more oxygen-adsorption capacity, and more basic sites.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Yongheng Xiong,Qin Zhong,Man Ou,Wei Cai,Shipeng Wan,Yang Yu,Shule Zhang
The discovery of effective methods toward nitric oxide (NO) removal by solution is valuable for the cost-effective flue gas control. In this study, it is first reported that nitrous oxide (N2O) is obviously suppressed by using copper oxide (CuO) combined with (NH4)2SO3 (NS) solution. CuO has been characterized, and the effects of reactants concentration, additives, temperature, pH and powder size on NO absorption process have been evaluated. The selectivity of N2O can drop from 91.30% to 11.25% under the optimum experimental conditions. Furthermore, based on the method of single-factor analysis, the inhibition of N2O is identified as the coeffect of NS/CuO. In addition, the pathways of NO removal are divided into two parts—N2O formation and NO absorption—and its ratio is calculated in the range of 0.29–0.53. Because of the continuous supply of NS from ammonia desulfurization, this study opens the feasibility of simultaneous desulfurization and denitrification.
研究领域:
环境科学
·
化学工程
·
大气污染控制
✓ 已验证
产品关联
DOI
高影响因子
Agronomy-Basel
·
2024
·Vol. 14
·期 6
·1113
·
IF 3.3
Jing Wang,Linfang Guo,Fengmin Yang,Jian Xiang,Lizhi Long,Kang Ni
The excessive application of nitrogen in tea plantations leads to severe soil acidification and N2O emission boosting. To promote sustainable agriculture, nanoparticles (NPs) have emerged as alternative fertilizers, but their effects on soil nitrification and greenhouse gas emissions in tea plantations remain unclear. In this study, the effects of NP type (ZnO-NPs and Fe2O3-NPs) and dose (0, 1, 10, and 100 mg·kg−1) on soil N2O emissions were investigated via a lab incubation trial. Soil pH, ammonium, and nitrate changes were also monitored during the incubation period. The abundance of functional genes related to nitrification and denitrification processes was analyzed as well. The results showed that ZnO-NPs led to a decrease in N2O emissions. The reduction effect was stronger with increasing dose and resulted in a 33% reduction at an addition rate of 100 mg·kg−1. The cumulative N2O emissions had significantly positive correlations with NH4+-N and NO3−-N. ZnO-NP addition showed a significantly negative effect on Ammonia-Oxidizing Archaea (AOA) but a positive effect on Ammonia-Oxidizing Bacteria (AOB) gene abundance. In contrast, Fe2O3-NPs showed an insignificant impact on N2O emissions and soil N content, as well as nitrification–denitrification gene abundance, regardless of different doses. These results imply that the application of ZnO-NPs may inhibit nitrification through the retarding of AOA activity. This study provided us with a potential practice to reduce N2O emissions in tea plantations by applying ZnO-NPs, but the efficiency of this reduction needs further examination under ambient conditions before field application.
研究领域:
农业生态学
·
微生物学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Hairong Tang,Yong He,Peixi Liu,Jiaming Shao,Fawei Lin,Zhihua Wang
Zeolitic-imidazolate framework precursors (ZIF-67) were synthesized in an inorganic solution with triethylamine as a deprotonating agent for N2O decomposition, and the catalytic activities of the pyrolysis products under different conditions were investigated. Among them, the Co/CoOx@carbon catalyst pyrolyzed at 650 °C in a N2 atmosphere (Co-650N) exhibited excellent low-temperature catalytic activity and stability, achieving 50% decomposition efficiency at 305 °C and ∼100% at 400 °C, which benefitted from its large specific surface area, great reduction performance, abundant cobalt active sites, and surface oxygen species. Further, utilizing temperature-programmed desorption (TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS) results, it was found that N2O molecules preferentially combined with oxygen species bound to cobalt sites. The absorbed N2O was decomposed into N2 and oxygen species, and the latter was subsequently transferred to carbon frameworks. Interestingly, the amorphous graphitic carbon frameworks played an important role in transferring/storing active oxygen and regenerating cobalt sites. Moreover, Co-650N exhibited better resistance to SO2, and the efficiency could be recovered via heating and finally stabilized at 100%. Finally, the mechanisms of N2O decomposition and sulfur poisoning-reactivation on Co/CoOx@carbon catalysts were proposed for the first time.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Kaixuan Feng,Ruixiang Lin,Tingyu Chen,Yuyan Hu,Yuheng Feng,Dezhen Chen,Mudassir Hussain Tahir,Tongcheng Cao
In this study, a catalytic system for N 2 O reduction by H 2 onto char decorated with transition metals is proposed, which have excellent reduction efficiency at low temperatures below 200 °C and efficiently utilizes pyrolysis char and hydrogen. Density functional theory (DFT) is used to reveal the reaction mechanism and found that transition metal decoration can significantly promote reaction rate and decrease the activation energy required for N 2 O reduction by H 2 on char, from 383.7 kJ/mol to 50–160 kJ/mol. Furthermore, transition states in the process of reducing N 2 O by H 2 over metal-char were observed, including reduction of N 2 O and the removal of the surface oxygen complex. Through kinetic analysis , the activation energy and reaction rate order was found as Ni-char (50.0 kJ/mol)>Co-char (95.1 kJ/mol)>Fe-char (151.0 kJ/mol)>Cu-char (158.8 kJ/mol). According to experiments phenomenon, the sequence of reduction efficiency over different metal-char was consistent with the simulation results and it was even possible to convert N 2 O to N 2 below 200 ℃. This research contributes to a more mechanistic understanding of the N 2 O-H 2 reaction over char and provides new insights for improving the design of catalysts for N 2 O abatement at low temperatures.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Yunshuo Wu,Xuanhao Wu,Jie Fan,Haiqiang Wang,Zhongbiao Wu
Iron zeolites are promising candidates for mitigating nitrous oxide (N2O), a potent greenhouse gas and contributor to stratospheric ozone destruction. However, the atomic-level mechanisms by which different iron species, including isolated sites, clusters, and particles, participate in N2O decomposition in the presence of CO still remain poorly understood, which hinders the application of the reaction in practical technology. Herein, through experiments and density functional theory (DFT) calculations, we identified that isolated iron sites were active for N2O activation to generate adsorbed O* species, which readily reacted with CO following the Eley–Rideal (E-R) mechanism. In contrast, Fe2O3 particles exhibited a different reaction pathway, directly reacting with CO to generate oxygen vacancies (Ov), which could efficiently dissociate N2O following the Mars-van Krevelen (MvK) mechanism. Moreover, the transformation of iron oxide clusters into undercoordinated FeOx species by CO was also revealed through various techniques, such as CO-temperature-programmed reduction (TPR), and ab initio molecular dynamics (AIMD) simulations. Our study provides deeper insights into the roles of different iron species in N2O-SCR by CO, and is anticipated to facilitate the understanding of multicomponent catalysis and the design of efficient iron-containing catalysts for practical applications.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Xuebin Hu,Yiyu Wang,Xiaoxuan Su,Yi Chen
The fungicide chlorothalonil (CHT) has been widely used in the tea orchard due to its high-efficiency and sterilization. It has been reported that repeated application of CHT inhibits soil nitrification process. However, the acute impact of CHT on soil denitrification and associated N 2 O emissions is unclear. This study evaluated nitrate (NO 3 − ) removal, denitrifying gene abundance and denitrifying enzyme activity of tea orchard soil after a 72-h-exposure to CHT. It was found that increasing CHT from 5 to 25 mg kg −1 suppressed the NO 3 − removal efficiency from 74.6% to 54.1%, but increased N 2 O emissions from 23.1% to 94.8%. Following treatment with 25 mg kg −1 of CHT, the abundances of the nir K, nir S and nos Z genes were reduced by 31.6%, 22.1%, and 50.7%, respectively. Alternatively, the declines of the electron transport system activity (ETSA) value and adenosine triphosphate (ATP) content suggested that CHT had an inhibitory effect on microbial metabolism. Enzyme activity studies further revealed that the decrease of nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR) activities was the main reason for the suppression of denitrification by CHT. Furthermore, positive correlations were observed between denitrifying reductase activity and the intracellular metabolism, indicating that the decrease in microbial metabolism should also be responsible for the inhibitory effect of CHT on the denitrifying process. Overall, it was found that the acute exposure of soil to CHT could inhibit the denitrification process and significantly increase N 2 O emissions, which might result in destruction of the soil nitrogen cycle and exacerbation of global warming .
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
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