SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Linfeng Miao,Xiaolin Wu,Zhongli Ji,Zhen Zhao,Cheng Chang,Zhen Liu,Feng Chen
Different drying conditions and three types of porous fibrous ceramics with different contents and dispersions of the silica-based binder were used to prepare catalytic filter elements (CFEs) for the simultaneous removal of NO x and dust, and their effects on the catalytic performances were also investigated. The results indicated that the content and dispersion of the silica-based binder had a significant effect on the catalytic activity of the CFE. The removal of useless binder in the pores and the inhibition of binder agglomeration could improve the NO conversion. Compared with traditional electric heating blast drying, microwave drying effectively inhibited the migration of titanium sol so that the catalyst in the prepared CFE had good uniformity and dispersion. Meanwhile, microwave drying changed the morphology, crystal grain, and pore structure of the catalyst support (TiO 2 ), ultimately increasing the specific surface area. Furthermore, this study also determined that the optimal average output power for microwave drying was 385 W. With a filtration velocity of 1 m/min, NO and NH 3 inlet concentrations of 600 ppm, and an O 2 content of 5 vol%, the prepared CFE achieved more than 98% NO conversion in the temperature range of 250 to 350 °C, and its highest conversion of 100% was achieved at 275–325 °C.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 6
·1062-1069
·
IF 1.071
Wang Hui,Wang Jiafeng,Zhang Lei,Yu Qinqin,Chen Zewen,Wu Shengji
In the present work, a remarkable combination of non-thermal plasma and photocatalyst was developed to widen the operating temperature window of selective catalytic reduction(SCR) of NO x with CH 4 , especially to improve the low-temperature removal efficiency of NO x . It was shown that the operating temperature window was significantly widened. Among all the catalysts prepared, 1%Ag 2 O/TiO 2 showed the highest catalytic activity for NO x removal due to the utilization of near ultraviolet light. The conversion of NO x to N 2 over the in-plasma 1%Ag 2 O/TiO 2 photocatalyst at 60 and 300 °C could achieve 31.8% and 53.0%, respectively. The combination mode of plasma and catalyst affected NO x removal efficiency greatly, the in-plasma catalysis outperformed the post-plasma catalytic mode remarkably, signifying the contribution of photocatalytic processes on the catalysts. Meanwhile, the characterizations of the catalyst demonstrated that the morphology and structure of the Ag 2 O/TiO 2 catalyst were unchanged throughout the non-thermal plasma and photocatalytic processes, implying the superior stability of the catalyst.
研究领域:
环境科学
·
催化化学
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产品关联
DOI
高影响因子
Nano Research
·
2024
·
IF 9.5
Liu Dong-Xue,Deng Xin,Zhu Yong-Fu,Meng Zhe,Sun Xue-Feng,Shi Miao-Miao,Zhong Hai-Xia,Yan Jun-Min
Electrocatalytic reduction of nitrate \(({\rm{N}}{{\rm{O}}_3}^ - )\) and nitride \(({\rm{N}}{{\rm{O}}_2}^ - )\) to ammonia (NH 3 ) is of wide interest as a promising alternative to the energy-intensive Haber-Bosch route for mitigating the vast energy consumption and the accompanied carbon dioxide emission, as well as benefiting for the relevant sewage treatment. However, exploring an efficient and low-cost catalyst with high atomic utilization that can effectively facilitate the slow multi-electron transfer process remains a grand challenge. Herein, we present an efficient hydrogenation of \({\rm{N}}{{\rm{O}}_3}^ - /{\rm{N}}{{\rm{O}}_2}^ - \) species to NH 3 in both alkaline and neutral environments over the Fe 2 (MoO 4 ) 3 derived hybrid electrocatalyst with the metallic Fe site on FeMoO 4 (Fe/FeMoO 4 ). The Mo ingredient can play a synergistically positive role in further promoting the NH 3 production on Fe. As a result, Fe/FeMoO 4 behaves well in the electrochemical NH 3 generation from \({\rm{N}}{{\rm{O}}_2}^ - \) with a maximum NH 3 Faradaic efficiency (FE) of 96.53% and 87.68% in alkaline and neutral electrolyte, corresponding to the NH 3 yield rate of 640.68 and 302.56 \({\rm{mg}} \cdot {{\rm{h}}^{ - 1}} \cdot {\rm{m}}{{\rm{g}}_{{\rm{cat}}.}}^{ - 1}\) , respectively, which outperforms the Fe and Mo counterpart and other similar catalyst, showing the robust catalytic capacity of each active site.
研究领域:
催化
·
电化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Zhong-yi Wang,Rui-tang Guo,Xu Shi,Wei-guo Pan,Jian Liu,Xiao Sun,Shuai-wei Liu,Xing-yu Liu,Hao Qin
The Cu/TiO 2 catalysts modified by Sb were compounded through the sol-gel way and put into use for the selective catalytic reduction (SCR) of NOx with NH 3 . Experimental results suggested that CuSb/TiO 2 -0.4 exhibited the excellent NOx conversion and SO 2 tolerance. Subsequently, the relationship between surface physicochemical properties and catalytic performance was also investigated by different characterization methods. From characterizations, the introduction of Sb for Cu/TiO 2 could promote the generation of more Cu 2+ , surface adsorbed oxygen species and surface acid sites on CuSb/TiO 2 -0.4 catalyst. Furthermore, Sb species on CuSb/TiO 2 -0.4 could contribute to the formation of more surface ad-NOx and ad-NH 3 species, which would enhance the NH 3 -SCR process effectively through both the Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
VACUUM
·
2024
·
IF 3.8
Hailin Zheng,Min Zheng,Xianxing Huang,Mingjie Liang,Kang Li
Chemical-looping combustion (CLC) technology is considered a promising combustion method with inherent CO 2 capture. In this study, the sol-gel method and combustion synthesis were employed to produce precursor materials (P) of CuO-based oxygen carriers (OCs). The effects of vacuum drying conditions on both NO x emissions from precursor combustion and oxygen carrier cycle reaction characteristics were investigated. Vacuum-dried precursors emitted less NO x during the precursor calcination process. At a heating rate of 1 °C/min, the vacuum-dried precursors exhibited an average reduction of 24.13 % in NO x emissions compared with those prepared through atmospheric pressure drying. An increased amount of Cu 2 (OH) 3 NO 3 in the precursor results in greater heat release during the self-propagating high-temperature combustion synthesis used to synthesize the oxygen carrier. Furthermore, the complete combustion of the nitrogen-containing precursor leads to a reduction in the emission of NO x . CuO-based OCs exhibited stable redox reactions over 10 cycles. Vacuum drying enhanced CH 4 conversion and CO 2 yield of OC1 by 14.04 % and 13.21 %, respectively, compared to atmospheric pressure drying. The results indicate that the CuO-based OCs obtained through vacuum-dried significantly enhance redox properties. This study shows that vacuum-dried reduces NO x emissions from nitrogen precursors and enhances the cyclic efficiency of OCs from precursor combustion.
研究领域:
能源科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Guobo Li,Kai Shen,Ling Wang,Yaping Zhang,Hongqiang Yang,Peng Wu,Bing Wang,Shule Zhang
Development of an efficient synergistic degradation technology to prevent the emission of chlorinated organics and NO x from industrial sources without forming harmful by–products, is a major challenge in environmental chemistry. The designed multi–active center catalyst (PdV/TiO 2 ) showed excellent CB/NO synergistic removal conversion efficiency and target product selectivity. Experimental and DFT calculation results indicated that Pd was the common center for adsorption of CB, O 2 , NH 3 and NO x molecules. The O vacancies (VO x –1 and TiO x –1 ) generated during the CB ring opening process was conducive to adsorption of reaction gas molecules, accelerating CBCO and NH 3 –SCR reaction. The adsorbed NH 3 species would dissociate H protons to provide Brønsted acidic sites necessary for Cl conversion. O vacancies structure was easier to be restored by reoxidation with the participation of NO 2 . Certain synergistic effect in the removal of CB and NO on the multi–active center catalyst surface was found.
研究领域:
环境化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Chenxi Wang,Gang Lv,Yunqiang Li,Ye Liu,Chonglin Song
The selective catalytic reduction of nitrogen oxides by methane (CH 4 /NO X -SCR) is a potential technique for the abatement of the NO X emissions from lean-burn GDI engines, due to the excellent thermal stability of CH 4 . This work focuses on the promotion of In/SSZ-13 catalysts by Ce modification for the CH 4 /NO X -SCR performance at high temperatures. A series of In/SSZ-13 and Ce-In/SSZ-13 catalysts were prepared using the wetness impregnation method. The effects of Ce modification on the catalytic performance were analysed in detail using the scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectrum and temperature-programmed desorption/reduction techniques. The results show that the Ce modification significantly enhances the high-temperature activity of the In/SSZ-13 catalysts for the NO X -SCR reaction, especially for the 5 wt% Ce-15 wt% In/SSZ-13 sample which has more than 75% NO X conversion at 390–700 °C. In addition, the Ce modification enhances the water vapor tolerance of the catalyst sample. The Ce modification increases not only the concentration of surface chemisorption oxygen species, but also the relative amount of InO + species which serve as the main active sites for CH 4 activation. Furthermore, the incorporation of Ce into In/SSZ-13 greatly promotes NO X adsorption on the catalyst surface. Most importantly, the Ce modification makes In species well-dispersed on the catalyst surface and thus suppresses the formation of bulk In 2 O 3 species which are more active for the CH 4 non-selective oxidation. The combination of all these effects results in the Ce-In/SSZ-13 samples with the superior catalytic activity .
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Chemical Engineering Journal Advances
·
2020
·
IF 0
Jiuhu Zhao,Zhengzhong Wen,Rongshu Zhu,Zhi Li,Ran Ding,Yongji Zhu,Tingkun Gu,Rong Yang,Zhenye Zhu
In this paper, In-metal oxide/H-Beta catalysts were synthesized by ion exchange method and In-Co 3 O 4 /H-Beta exhibited the highest catalytic activity for the selective catalytic reduction of NO x with CH 4 in presence of H 2 O and SO 2 . Thus, the synthesis conditions of In-Co 3 O 4 /H-Beta were optimized. The results showed that In-Co 3 O 4 /H-Beta exhibited excellent catalytic performance and high CH 4 selectively when the synthesis was carried out by ion exchange method, the ratio of Si and Al in H-Beta was 25, the ratio of Co 3 O 4 and H-Beta was 5:40, the concentration of ion exchange liquid was 0.033 M and calcination temperature was 500 °C. The NO x removal efficiency was about 87.6 % and N 2 selectivity could reach 96.3% in the presence of H 2 O and SO 2 . Through a series of characterizations, it was concluded that In-Co 3 O 4 /H-Beta owned stable catalyst structure, abundant Brønsted acid sites and the highest ratio of InO + /In 2 O 3 under the optimal synthesis conditions. In addition, the doped of Co 3 O 4 could inhibit the adsorption of sulfate species on the surface of In/H-Beta catalyst, leading to the excellent H 2 O and SO 2 resistance property.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Bo Feng,Tingman Zhao,Jiada Du,Jiyuan Hu,Yun Shi,Jingkai Zhao,Jianmeng Chen
Methane selective catalytic reduction (CH 4 -SCR) technology has shown promise for controlling NO x emissions from natural gas generator sets. This study presents a highly efficient Ce 30 In 15 /HBEA catalyst featuring dual active sites, Al-O – (InO + )-Si site for CH 4 activation and ceria oxygen vacancy (Ce 3+ -□) site for NO x activation. However, the CH 4 -SCR activity of this catalyst decreased in the presence of H 2 O, SO 2 , C 3 H 6 , and CO 2 . The inhibitory effects on CH 4 -SCR activity followed by the sequence: H 2 O > SO 2 > C 3 H 6 > CO 2 . In particular, H 2 O combined with Al-O – (InO + )-Si to form inactive In(OH) 3-z z+ species and occupied Ce 3+ -□, preventing Ce 4+ -NO 3 – /NO 2 – formation. In/Ce sulfate formation via the reaction between SO 2 and In/Ce active sites hindered CH 4 and NO x adsorption and activation. The formed carbon deposits covered the active sites on the catalyst surface due to incomplete C 3 H 6 oxidation . In comparison, the dual active sites were almost unaffected by CO 2 . Overall, this study provides a basis for the rational design of novel catalysts for CH 4 -SCR.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Jianwen Lai,Hongbo Qi,Yunfeng Ma,Xiaoqing Lin,Xiaoying Wang,Zhongkang Han,Heidelore Fiedler,Xiaodong Li
Cerium is widely used as a modifier to enhance the catalytic performance of the selective catalytic reduction (SCR) catalysts due to its exceptional low-temperature properties. However, the effects of different cerium precursors on catalytic performance remains unclear. In this study, VO x -WO x /TiO 2 catalysts are modified using Ce(NO 3 ) 3 ·6H 2 O (cata-N), CeO 2 (cata-O), and Ce(OH) 4 (cata-OH), and their synergistic removal of NO x and chlorobenzene (CB), as well as their resistance to water and sulfur poisoning, were systematically investigated. Among the tested catalysts, cata-N demonstrated superior CB (45.0–93.3 %) and NO x (31.9–90.37 %) removal efficiencies under synergistic conditions, along with excellent water resistance (T 90 = 193 °C with 5 % H 2 O). In contrast, cata-OH exhibited the highest sulfur resistance, maintaining a denitrification efficiency of 20 % after 10 h of sulfur exposure, compared to 9 % for cata-N and 8 % for cata-O. Characterization revealed that Ce(NO 3 ) 3 ·6H 2 O improved cerium dispersion, leading to enhanced the redox properties and acidity (especially Brønsted acid sites (BAS)) in cata-N. Density functional theory (DFT) calculations and In-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy ( In-situ DRIFTS) results revealed that the well-dispersed cerium atoms contributed additional BAS in the form of Ce–OH, while also forming Ti–O–Ce bonds. These Ti–O–Ce bonds facilitated the formation of Ti–OH on the TiO 2 surface. Ti–OH significantly enhanced the adsorption of NH 3 and CB, thereby promoting both the NH 3 -SCR and CB oxidation processes. This study offers new insights into the role of cerium precursors and provides a practical strategy for tuning BAS of catalysts in multiple pollutants removal.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Liuyang Yang,Meiqing Shen,Xinhua Li,Liwei Jia,Feng Gao,Wei Li,Xinyu Li,Gurong Shen
Passive NO x adsorbers (PNAs) are promising materials for mitigating cold-start NO x emissions, yet their performance is often limited by poor adsorption kinetics and insufficient hydrothermal durability. Herein, we report a triethanolamine (TEOA)-assisted synthesis strategy for Mn/CeZrO x PNAs that enables highly dispersed MnO x species with strengthened Mn-support interactions. Compared with conventionally prepared Mn/CeZrO x , the TEOA-modified materials exhibit (i) faster NO x adsorption rates during the initial cold-start relevant stage, (ii) a higher nitrate formation rate and a more suitable nitrate decomposition window (200–400 °C) in which the downstream selective catalytic reduction unit utilizing Cu-SSZ-13 SCR catalysts typically displays optimized NO x reduction efficiency, and (iii) enhanced hydrothermal stability with reduced MnO x agglomeration after aging. A combination of spectroscopic and microscopic techniques (XPS, UV–vis, DRIFTS, TEM/EDS) reveal that TEOA modulation promotes uniform MnO x dispersion, increases surface O ads species, and shifts MnO x speciation toward more active states. These structural and chemical modifications collectively account for the improved PNA performance. This work demonstrates a simple yet effective synthesis approach to optimize Mn-based PNAs, providing new insights into the design of thermally robust, precious-metal-free cold-start NO x control materials.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Zhao Zhang,Song Zhou,Hongyuan Xi,Majed Shreka
A high nitrate concentration in scrubber water is a major factor that restricts ship applications of NOx wet absorption technology. In this paper, an absorption system (Na2SO3/NaHSO3) that can effectively improve NO2 absorption and reduce the concentrations of nitrate and nitrite was studied. Several factors that affect the NOx absorption efficiency and the concentrations of nitrate and nitrite were investigated in a bubble reactor by using Na2SO3 and Na2SO3/NaHSO3. In addition, the reaction mechanism for the process of NO2 absorption was deduced. The results illustrate that increases in S(IV) concentration and initial NO2 concentration could enhance the NOx absorption efficiency while increases in the NO/NO2 ratio and SO2 concentration decreased the NOx absorption efficiency. Moreover, the maximum NOx absorption efficiency was 97.8% at 0.15 mol/L S(IV) and 1400 ppm of NO2 when using the Na2SO3/NaHSO3 absorption system. The S(IV) concentration was the main factor affecting the NOx absorption efficiency and the concentrations of nitrate and nitrite. Increasing the SO2 concentration slightly affected the NOx absorption efficiency but was beneficial for decreasing the concentrations of nitrate and nitrite. The performance of the Na2SO3/NaHSO3 absorption system was better than that of Na2SO3 in the presence of oxygen. Furthermore, the minimum concentrations of nitrate and nitrite were 13.5 and 0 mg/L, respectively, in the Na2SO3/NaHSO3 absorption system for 1100 ppm of NO2 and 0.3 mol/L S(IV) and were much lower than current regulations for scrubber water. Finally, compared with other experimental results, the Na2SO3/NaHSO3 absorption system exhibits great potential for ship NOx wet absorption, and the addition of NaHSO3 plays a key role in decreasing the concentrations of nitrate and nitrite.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）