INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Cheng Shen,Peng Wang,Laihong Shen,Xianglei Yin,Zhenwu Miao
Alkaline earth metal chlorides (AEMH) are considered to be the key to effectively solving the problem of NH3 storage due to their ability to react with NH3 to form stable ammonia complexes. This study attempted to investigate the NH3 adsorption performance of four metal chlorides (CuCl2, MnCl2, MgCl2, and CaCl2) and silicon-supported composite adsorbents with a fixed bed. The adsorbents were characterized by X-ray diffraction, Brunauer–Emmett–Teller, and scanning electron microscopy to analyze the NH3 adsorption behavior. The experiment found that the NH3 adsorption capacity of four metal chlorides is in order: CuCl2 > MnCl2 > MgCl2 > CaCl2, and the adsorption capacity of metal chlorides decreased with the increase in temperature. In addition, the composite adsorbents of silicon-supported metal chlorides were synthesized by the wet impregnation method. Ammonia adsorption experiments showed that silicon can significantly improve the NH3 adsorption capacity of metal chlorides, and the NH3 adsorption capacity of MnCl2/silicon was 127.5% higher than that of MnCl2. Silicon played the role of the skeleton support in the metal chloride particles, hindering the agglomeration between particles and increasing the number of pores on the surface of the particles, which was conducive to the diffusion of NH3 through the pores into the particles for adsorption.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Environmental Science & Technology Letters
·
2023
·
IF 10.9
Lin Du,Li Xu,Kun Li,Christian George,Maofa Ge
Anthropogenic air pollutants can be involved in biogenic secondary organic aerosol (SOA) formation. However, such interactions are currently one of the least understood aspects of atmospheric chemistry. Herein, SOA formation via chemical interactions between anthropogenic SO2, NH3, and O3 and biogenic β-caryophyllene was investigated. It is shown that although SO2 considerably enhanced SOA formation, this enhancing effect was weakened by NH3 when SO2 and NH3 coexisted. NH3-induced neutralization of particle acidity generated by SO2 oxidation may be the primary driving factor of this weakening effect. Molecular-level characterization using high-resolution quadrupole time-of-flight mass spectrometry revealed additional connections between NH3-induced changes in SOA composition and aerosol acidity. Specifically, the lower relative abundances of several main products generated in the presence of SO2 and NH3 than those formed in the presence of only SO2 were consistent with their suppressed formation by lower seed acidity. The suppression of oligomer formation by NH3 provided more evidence for the weakening of acid-catalyzed processes caused by acidity neutralization. Accordingly, the current study demonstrates that NH3 as a less effectively regulated alkaline gas resulting from an unbalanced reduction of different pollutants must be considered with caution when evaluating effects of SO2 on SOA formation via anthropogenic–biogenic interactions.
研究领域:
大气化学
·
环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 7
·3858-3868
·
IF 2.936
Shuohan Yu,Sheng Xu,Bowen Sun,Yiyang Lu,Lulu Li,Weixin Zou,Peng Wang,Fei Gao,Changjin Tang,Lin Dong
Chromium oxide nano-particles with an average diameter of 3 nm covered by amorphous carbon (CrOx/C) were successfully synthesized. The synthesized CrOx/C materials were used for the selective catalytic reduction of NOx by NH3 (NH3-SCR), which shows superb NH3-SCR activity and in particular, satisfactory regeneration ability in the presence of SO2 compared with Mn-based catalysts. The as-prepared catalysts were characterized by XRD, HRTEM, Raman, FTIR, BET, TPD, TPR, XPS and in situ FTIR techniques. The results indicated presence of certain amounts of unstable lattice oxygen exposed on the surface of CrOx nano-particles with an average size of 3 nm in the CrOx/C samples, which led to NO being conveniently oxidized to NO2. The formed NO2 participated in NH3-SCR activity, reacting with catalysts via a “fast NH3-SCR” pathway, which enhanced th NH3-SCR performance of the CrOx/C catalysts. Furthermore, the stable lattice of the CrOx species made the catalyst immune to the sulfation process, which was inferred to be the cause of its superior regeneration ability in the presence of SO2. This study provides a simple way to synthesize stable CrOx nano-particles with active oxygen, and sheds light on designing NH3-SCR catalysts with highly efficient low temperature activity, SO2 tolerance, and regeneration ability.
研究领域:
催化
·
环境工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Zhenwen Yang,Ziyi Shui,Mengfei Zhao,Zheng Wei,Fenglian Zhang,Xiaoxiao Duan,Ben Niu,Bingzhi Li,Guoxia Jiang,Zhengping Hao
Catalytic NH3 decomposition has drawn growing interest in constructing the NH3-based hydrogen economy. Ni catalysts show great potential in this reaction but suffer from low atom utilization efficiency and unclear structure–activity relationship. Here, atomic layer deposition was used to grow Ni clusters on CeO2 nanorods to create a highly active catalyst for NH3 decomposition, which outperforms the conventional Ni nanoparticle catalysts and the synthesized Ni single-atom catalyst. The distinct catalytic behaviors of Ni clusters and Ni single atoms were systematically investigated. It is revealed that the interfacial confinement effect induces a strong electronic interaction between Ni clusters and CeO2, wherein abundant Ov-Ce3+ sites are formed in the vicinity of Ni clusters, resulting in interfacial electron-enriched Niδ− sites. These Niδ− sites bind to N adatoms moderately, favoring N–H bond cleavage and nitrogen desorption (the rate-determining step), which is the origin of the high activity. In contrast, ionic Ni single atoms diffusing into the CeO2 lattice display a much lower activity since strongly bound N adatoms block the active sites and retard the overall rate. This work provides a deep understanding of Ni-catalyzed NH3 decomposition and paves the way for designing high-performance metal catalysts for other structure-sensitive reactions.
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
Sustainability
·
2022
·Vol. 14
·期 9
·5353
·
IF 3.889
Kun Li,Tao Zhou,Xinqiang Xu,Changye Han,Hua Zhang,Jiang Jin
Mn-Co-based catalysts were loaded to ceramic filters element by impregnation for the coprocessing of dust and nitrogen oxide (NOx) in flue gas. The influence of the Mn/Co ratio and loading on the catalytic performance was investigated. The Mn-Co-based catalytic ceramic filter with a Mn/Co molar ratio of 2/1 can achieve 99% NO conversion by selective catalytic reduction of NOxwith NH3(NH3-SCR) in the temperature range of 100−180 °C, but its resistance to H2O was relatively poor. The filter element was modified by PTFE to improve the H2O resistance. After modification, the catalytic ceramic filter showed superior resistance to H2O and SO2at low temperatures (100–180 °C) and satisfactory self-cleaning performance.Keywords:NH3-SCR;catalytic ceramic filter;PTFE-modified;H2O resistance
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 PHYSICS-CONDENSED MATTER
·
2022
·Vol. 34
·期 37
·374002
·
IF 2.745
Xiao Chang,Xiaofang Li,Qingzhong Xue
Exploring novel NH3 sensing materials is crucial in chemical industries, fertilizing plants and medical fields. Herein, for the first time, the NH3 sensing behaviors and sensing mechanisms of two dimensional (2D) ZnTe monolayer are systematically investigated by density functional theory calculations. It is shown that 2D ZnTe monolayer exhibits excellent selective NH3 sensing properties. (220) crystal facet of ZnTe possesses a higher NH3 adsorption energy (−1.59 eV) and a larger charge transfer (0.195e) than (111) and (311) crystal facets. The positive charges could enhance NH3 sensing while the negative charges could reduce NH3 sensing. The NH3 adsorption strengths are significantly improved in O2 atmosphere while it is negligibly affected by N2 atmosphere and H2O atmosphere. Moreover, the presence of Zn vacancy and Fe, Co, Ni doping could improve the NH3 sensing of ZnTe. Additionally, the experimental results confirms that ZnTe possesses a low detection limit of 0.1 ppm NH3. These theoretical predictions and experimental results present a wide range of possibilities for the further development of ZnTe monolayer in NH3 sensing fields.
研究领域:
材料科学
·
化学传感器
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RARE METALS
·
2021
·Vol. 41
·期 1
·166-178
·
IF 4.003
Zhang Bo-Lin,Deng Li-Feng,Liu Bo,Luo Chun-Yun,Liebau Michael,Zhang Shen-Gen,Gläser Roger
Abstract Combining the redox properties of Co and the acid properties of Nb in a Co 3 -Nb-O x catalyst is shown to provide superior performance in the selective catalytic reduction of NO with NH 3 (NH 3 -SCR). Co 3 O 4 shows average activity, however, it exhibits a poor N 2 selectivity. Nb 2 O 5 is not active for NH 3 -SCR. However, the mixed Co 3 -Nb-O x catalyst shows higher NO conversion and N 2 selectivity than the single Co 3 O 4 and Nb 2 O 5 catalysts at 100–300 °C. The results of temperature programmed reduction by H 2 and X-ray photoelectron (XP) spectra indicate that the addition of Nb changes the chemical states of Co and decreases the concentration of Co 3+ and O α , adjusting the activity for catalytic oxidation to a moderate level. This suppresses the formation of undesired N 2 O from the over-oxidation of NH 3 . Incorporation of Co and Nb into one solid synergistically couples their redox behavior and surface acidity, ensuring the high catalytic activity and N 2 selectivity in NH 3 -SCR. Graphical Abstract
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Yi Li,Yanping Li,Pengfei Wang,Wenping Hu,Suge Zhang,Qiang Shi,Sihui Zhan
A series of MnFeO x nanorods with different Fe/Mn molar ratios were successfully synthesized by the hydrothermal method for low temperature selective catalytic reduction (SCR) of NO x with NH 3 . These MnFeO x catalysts have been systematically characterized by SEM, TEM, XRD and XPS. Furthermore, the MnFe (0.1) O x showed the highest catalytic performance with nearly 100% of NO x removal efficiency from 200 to 350 °C. On the basis of the TPR, BET and in situ DRIFT results, it can be found that the addition of Fe species induced a possible redox reaction process and increased the surface chemisorbed oxygen concentration and acid sites, which should be responsible for the enhanced SCR activity of MnFe (0.1) O x . Meanwhile, several important process parameters affecting NO x removal efficiency in NH 3 -SCR were carried out, such as time, H 2 O and SO 2 .
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
Frontiers of Environmental Science & Engineering
·
2017
·Vol. 12
·期 1
·1-7
·
IF 1.716
Shi Jin,Zhang Zihao,Chen Mingxia,Zhang Zhixiang,Shangguan Wenfeng,Gu Shunchao,Shin-ichi Hirano
Fe-BEA catalysts are active for the NH3-SCR of NO. For industrial application, a binder should be added to the Fe-BEA catalysts to make them tightly adhere to the monoliths. The addition of alumina and zirconia as binders to the Fe-BEA led to a different effect on NO conversion. The catalytic activity of the mixed samples was evaluated by the temperature programmed procedure in a flow-reactor system, and the mechanism was analyzed via SEM, BET, XRD and XPS. It was found that larger iron particles were formed by the migration of parent iron particles in the Fe-BEA catalyst with alumina. This led to the increase of Fe 3+ magnitude and iron cluster, enhancing the abilities of NO oxidation and storage. Accordingly, the SCR activity increased slightly in low temperature but decreased sharply in high temperature. For the Fe-BEA with zirconia sample, NO oxidation and storage abilities decreased due to the less iron clusters. The increase of Fe 3+ magnitude resulted in higher catalytic oxidation ability, which gave rise to little change in the SCR activity compared with the Fe-BEA.
研究领域:
催化
·
环境科学
✓ 已验证
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 3
·324
·
IF 4.146
Jinkun Guan,Lusha Zhou,Weiquan Li,Die Hu,Jie Wen,Bichun Huang
SO2poisoning is a great challenge for the practical application of Mn-based catalysts in low-temperature selective catalytic reduction (SCR) reactions of NOxwith NH3. A series of Gadolinium (Gd)-modified MnOx/ZSM-5 catalysts were synthesized via a citric acid–ethanol dispersion method and evaluated by low-temperature NH3-SCR. Among them, the GdMn/Z-0.3 catalyst with the molar ratio of Gd/Mn of 0.3 presented the highest catalytic activity, in which a 100% NO conversion could be obtained in the temperature range of 120–240 °C. Furthermore, GdMn/Z-0.3 exhibited good SO2resistance compared with Mn/Z in the presence of 100 ppm SO2. The results of Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction of H2(H2-TPR) and temperature-programmed desorption of NH3(NH3-TPD) illustrated that such catalytic performance was mainly caused by large surface area, abundant Mn4+and surface chemisorbed oxygen species, strong reducibility and the suitable acidity of the catalyst. The in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) results revealed that the addition of Gd greatly inhibited the reaction between the SO2and MnOxactive sites to form bulk manganese sulfate, thus contributing to high SO2resistance. Moreover, in situ DRIFTS experiments also shed light on the mechanism of low-temperature SCR reactions over Mn/Z and GdMn/Z-0.3, which both followed the Langmuir–Hinshelwood (L–H) and Eley–Rideal (E–R) mechanism.Keywords:SO2poisoning;low temperature;NH3-SCR;in situ DRIFTS
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Zhenwen Yang,Ziyi Shui,Ben Niu,Xiaoxiao Duan,Zheng Wei,Guoxia Jiang,Zhengping Hao
NH 3 decomposition is receiving increased attention for on-site CO x -free H 2 generation. Unfortunately, the harsh reaction conditions often cause sintering of active metals. Here we report a simple method to achieve well Ni dispersion by nano-structuring the BN support with La species. The surface reaction-induced LaBO 3 nano-islands on BN support have a strong affinity for Ni atoms, which can capture and confine Ni species to yield a large population of well dispersed Ni clusters and nanoparticles. The Ni species selectively anchored on LaBO 3 islands expose more active sites and boost desorption of N 2 and H 2 , exhibiting superior activity and stability for NH 3 decomposition. In addition, it is revealed that the Ni dispersion is sensitive to the change of the support surface structure. These findings highlight the important role of support structure in determining the nature of the metal phase and provide guidance for designing catalysts with controlled catalytic structure and reactivity.
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
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Weiwei Meng,Lei Dai,Wei Meng,Huizhu Zhou,Yuehua Li,Zhangxing He,Ling Wang
Mixed-potential type NH 3 sensors were fabricated using La 10 Si 5.5 Al 0.5 O 27 (LSAO) consisting of a porous layer and a dense layer as solid electrolyte and TiO 2 as the sensing electrode. The effect of a LSAO porous layer and TiO 2 phase transformation on sensor performances was investigated. The porous layer of LSAO electrolyte obviously enhanced sensor performance. Compared with the sensor without a LSAO porous layer, the sensor with LSAO porous layer exhibited larger responding potential values and higher sensitivity due to the enhanced three phase interface length. Anatase-TiO 2 (a-TiO 2 ) based sensor exhibited better sensing performance than rutile-TiO 2 (r-TiO 2 ) based sensor at the examined temperature range. A-TiO 2 transformation toward r-TiO 2 resulted in poor sensing performances of the sensor. The best sensing characteristics were achieved for the NH 3 sensor with a-TiO 2 sensing electrode calcined at 900 °C for 3 h. The potential values of the sensor response to NH 3 linearly depended on the logarithm of NH 3 concentrations at 450–600 °C and the sensitivity reached 169.7 mV/decade in the range of 50–400 ppm at 500 °C. At the same time, the sensor exhibited well anti-interference capability to H 2 , NO, CH 4 and CO 2 , but a little cross-sensitivity toward NO 2 was observed. High temperature treatment (>900 °C) caused a-TiO 2 transformation into r-TiO 2 and V 2 O 5 additions were conducive to TiO 2 phase transformation.
研究领域:
材料科学
·
传感器技术
·
环境监测
✓ 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）