WATER AIR AND SOIL POLLUTION
·
2021
·Vol. 233
·期 1
·1-17
·
IF 2.52
Zhang Shujuan,Yun Wenfei,Xia Yu,Wu Sikai,You Zhaoyang,Matthias C. Rillig
This study aims to investigate the role of arbuscular mycorrhizal (AM) symbiosis in reducing N loss from paddy fields, using two rice lines: a mycorrhiza-defective rice line (non-mycorrhizal) and its mycorrhizal progenitor. Two rice lines were grown in the presence of an AM fungal isolate. In this study, N loss of runoff, leaching, N 2 O emission, and NH 3 volatilization were measured, and in addition, N uptake of rice, soil aggregates, and plant available N concentration of soil. The results obtained suggest that N loss via runoff, leaching, NH 3 volatilization, and N 2 O emission of mycorrhizal rice was 11%, 8%, 6%, and 1%, lower than that of non-mycorrhizal rice, respectively. Meanwhile, mycorrhizal rice has higher biomass and plant N uptake. Our study shows that the AM symbiosis contributes to the sustainability of rice production by reducing N loss, enhancing soil aggregation and increasing plant N uptake.
研究领域:
植物学
·
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yiqing Zeng,Fengye Lyu,Yanan Wang,Shule Zhang,Qin Zhong,Zhaoxiang Zhong
High N 2 O selectivity of MnO x -TiO 2 catalyst hinders its development in ammonia selective catalytic reduction (NH 3 -SCR) of NO x . Herein, a series of MnO x -TiO 2 catalyst with different Mn/Ti ratio were prepared by wet-impregnation method to study the N 2 O formation during ammonia selective catalytic reduction (NH 3 -SCR) of NO x from the perspective of catalyst. It is found that MnO x and TiO 2 species are the mainly redox and acid sites for the NH 3 -SCR denitration reaction over MnO x -TiO 2 catalyst, respectively. As the Mn/Ti ratio increases, MnO x species layer expanded on TiO 2 support, leading to increase of redox sites but decrease of surface acid sites. These changes contribute to the occurrence of the no-selective oxidation of NH 3 on MnO x species and the over-activation of NH 3 at Mn-Ti interface, resulting in the formation of N 2 O via the route of 2NH 3 + 2O 2 → N 2 O + 3H 2 O and 4NO + 4NH 3 + 3O 2 → 4N 2 O + 6H 2 O, respectively. Through this work, it can be speculated that both improving MnO x dispersion and increasing surface acidity of catalyst are feasible strategy for suppressing the N 2 O formation on MnO x -TiO 2 .
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
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
FUEL
·
2022
·
IF 8.035
Yangfan Chen,Hongyan Yan,Wenxin Teng,Jiangling Li,Weizao Liu,Shan Ren,Jian Yang,Qingcai Liu
NH 3 -SCR technology with commercialized V 2 O 5 -WO 3 (MoO 3 )/TiO 2 catalysts has become the most efficient technology for the removal of NO x from coal-fired power plants. However, the weaknesses of V 2 O 5 -WO 3 (MoO 3 )/TiO 2 catalysts such as the biotoxicity of vanadium species and high cost restrict their increased applicability. Fe 2 O 3 -based NH 3 -SCR catalysts show potential in placing traditional catalysts due to their good N 2 selectivity, excellent environmentally friendly performance, high thermal stability, and low cost. In this work, low cost Fe 2 O 3 -containing solid waste was exploited as the base material for NH 3 -SCR catalyst preparing. Moreover, bulk MoO 3 and MoO 3-x nanosheets decorated Fe 2 O 3 composite NH 3 -SCR catalysts were synthesized and both revealed conspicuously improved NO x removal efficiency compared with bare-Fe 2 O 3 catalyst. However, the N 2 selectivity of these two catalysts showed significant differences. Therefore, comprehensive characterizations, NH 3 oxidation experiments, and in-situ diffusion Fourier transform infrared spectroscopy (DRIFTS) experiments were performed to determine the N 2 O formation pathways of the above two catalysts. The redox properties were highly related to the N 2 O generated from NH 3 oxidation. Moreover, the huge difference in NH 3 and NO adsorption ability led to disparate reaction mechanisms over the two catalysts. This new understanding of the N 2 O formation mechanism has the potential to guide the rational design of improved NH 3 -SCR catalysts suffering from low N 2 selectivity.
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
CHEMOSPHERE
·
2022
·
IF 8.943
Ying Xiong,Yumei Zhao,Weijun Shan,Xiaogeng Feng,Junshuo Cui,Zhenning Lou,Guoxiang Shao,Min Dong,Haibiao Yu
In order to enhance the catalytic performance of the Gd-modified Co 3 O 4 catalyst (Gd 0.06 Co) for the N 2 O decomposition, alkali metal K was introduced as the promoter by impregnating the Gd 0.06 Co powder with an aqueous solution of KNO 3 (with K/Co ratios 0.01–0.05). With the doping of K, the catalytic activity over Gd 0.06 Co was significantly improved and the temperature of N 2 O complete decomposition was decreased from 350 °C to 300 °C. Combining the results of XPS and O 2 -TPD, the superior catalytic performance of the optimum catalyst K 0.025 Gd 0.06 Co was mainly owing to the synergistic effect of Gd and K, which weakened the Co–O bond and endowed the catalyst surface with much more amount of oxygen vacancies. Even under the coexist of the impurity gases, such as 5 vol% O 2 , 100 ppmv NO and 2 vol% H 2 O, the K 0.025 Gd 0.06 Co catalyst exhibited prominently better catalytic activity than Gd 0.06 Co and K 0.025 Co catalysts.
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Jiaying Xing,Qitong Xue,Jianjun Chen,Jinxing Mi,Xiaoping Chen,Jianqiang Shi,Zhiming Liu,Junhua Li
Vanadium-based catalysts play a pivotal role in the emission control of industrial NOx via selective catalytic reduction (SCR) technology. However, little attention has been paid to the potential emission of greenhouse gas N2O under complex working conditions. This work reports that a commercial V2O5/TiO2 catalyst may lead to significant N2O emission without greatly changing the outlet NOx concentration after chromium (Cr) deposition. With a Cr loading of 2 wt %, N2O concentration increased from 27.8 to 199.2 ppm at 350 °C with the value of outlet N2O/(N2O+N2) from 2.5% to 19.4%. Experimental results combined with DFT+U calculations suggest that nonselective catalytic reduction (NSCR) is the main route for N2O formation in a wide temperature range of 250 ∼ 400 °C. It is stemmed from the fact that the covalent interaction between Cr and V species on the V2O5/TiO2 surface accelerates the conversion of V4+ + Cr6+ → V5+ + Cr3+, leading to a larger proportion of surface V5+. More importantly, surface V5+ is highly related to the redox property of the V2O5/TiO2 catalyst, which is beneficial to NSCR reaction rather than the standard SCR process. The work suggests that to better inhibit the emission of greenhouse gases during the NH3–SCR process, monitoring N2O emission should be included along with the NOx concentrations, especially in complex flue gases.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2024
·
IF 2
Xin Yin,Jing Wang,Shufeng Shen
The water-lean absorbent of dimethyl sulfoxide (DMSO)/2-(butylamino)ethanol (BAE)/H2O has recently been proposed for energy-efficient CO2 capture. The CO2/N2O analogy method can provide important fundamental data for its kinetic study. In this work, the physical solubility of N2O and CO2 in DMSO was measured in a static equilibrium cell at temperatures of (293.15–333.15) K. Solubility of N2O in BAE and the BAE/DMSO binary blends with 22.6, 34.9, and 61.8 mass % BAE was also determined. The effect of the water content on N2O solubility in the water-lean ternary blends with 61.8 mass % BAE was also discussed. The ratios of solubility of CO2 to N2O in polar solvents (i.e., DMSO and water) were found to be very close at temperatures of 323–333 K. Experimental solubility data and the ones calculated from the recommended correlation models match well with each other, with average absolute relative deviations within 0.9%.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 10
·2825-2837
·
IF 4.4
Bin Kang,Mengfei Guo,Haotian Wu,Xiaonan Guo,Zhaoying Di,Ying Wei,Jingbo Jia,Zhou-jun Wang,Runduo Zhang
In this study, a series of alkali/alkaline-earth-metal doped Co3O4 spinel oxides was prepared for N2O catalytic decomposition. It was found that doping with alkali/alkaline-earth-metal ions essentially caused lattice distortion of M–Co3O4, decreased the crystal size, and increased the specific surface area and Co2+ (active sites) amounts. Physicochemical characterization of these as-prepared catalysts was performed, including Raman, XPS, H2-TPR, O2-TPD, and OIE, to indicate that M–Co3O4 has a high lattice oxygen mobility and is prone to form more oxygen vacancies. These oxygen vacancies were involved in N2O decomposition and synergistically promoted the reaction cycle of Co2+ sites. The catalytic activities were ranked in the order of Co3O4 < Mg–Co3O4 < Na–Co3O4 < Ca–Co3O4 < K–Co3O4 < Rb–Co3O4 < Cs–Co3O4, among which the best-performing sample (Cs–Co3O4) had a T90 that was nearly 200 °C lower than that of pure Co3O4, with the complete conversion of N2O achieved at 350 °C. In addition, the effects of alkali/alkaline-earth-metal doping on the lattice distortion, oxygen vacancy formation, N2O dissociation, and oxygen recombination and desorption of M–Co3O4 were verified using DFT calculations.
研究领域:
催化化学
·
环境化学
·
材料科学
·
物理化学
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Xiaoqin Shi,Shufeng Shen
Nonaqueous secondary alkanolamine-based systems, replacing conventional water with 2-alkoxyethanols as cosolvents, have recently attracted much attention for an energy-efficient CO 2 capture process. In this work, physical solubility of N 2 O and CO 2 in 2-(methylamino)ethanol (MAE), 2-methoxyethanol (2-ME) and their blends was measured and correlated at temperatures ranging from (283.2 to 333.2) K. Vapor-liquid equilibrium (VLE) data for the CO 2 + MAE + 2-ME system at 7.8, 19.4 and 39.1 mass% MAE were also measured in a stirred equilibrium cell at temperatures of (313.2–393.2) K and CO 2 partial pressures up to 270 kPa. VLE data were represented by a modified Kent-Eisenberg model with an AARD of 12.6%. The apparent equilibrium constants considering the liquid nonideality were well correlated as a function of temperature, concentration of carbamate product and CO 2 loading.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jiayi Qi,Xingkun Qi,Yan Pan,Junshuo Cui,Ying Xiong,Weijun Shan,Haibiao Yu
Sm 0.06 Ni with excellent H 2 O resistance for eliminating N 2 O was prepared by co-precipitation method. Research indicated that the introduction of Sm into Sm 0.06 Ni has the following effects: (1) Sm species (Sm 2 O 3 ) highly dispersed on the surface of Sm 0.06 Ni catalyst, which not only decreased the crystallite size of NiO, but also produced a certain number of edge dislocations and defects. (2) Sm 2 O 3 weakened the Ni-O band and increased the number of active sites. (3) The redox cycle of Ni 2+ + Sm 3+ ↔ Ni 3+ + Sm 2+ was formed on the surface of Sm 0.06 Ni during the reaction. Based on the above changes, Sm 0.06 Ni exhibited superior catalytic performance and much lower E a for the reaction compared with pure NiO. Over Sm 0.06 Ni, the TOF at 350 ℃ was 4.1 × 10 −3 s −1 , 37 times of that over pure NiO. More importantly, Sm 0.06 Ni exhibited excellent H 2 O resistance performance under submitted real reaction conditions, about 76 % N 2 O conversion can be obtained at 400 ℃.
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
危险品化学品经营许可证（带存储）