FUEL
·
2025
·
IF 7.5
Jianping Ding,Xiaoyan Zhou,Zhengzheng Yang,Changgeng Liu,Mingchao Sun,Congling Yang,Lu Fan
In this study, a novel strategy was proposed for synthesizing dual single-atom Ce-Ti catalysts supported on γ-Fe 2 O 3 via ball milling and calcination. Compared to γ-Fe 2 O 3 and single-atom Ce/γ-Fe 2 O 3 and Ti/γ-Fe 2 O 3 catalysts, the Ce-Ti/γ-Fe 2 O 3 catalyst exhibits superior NO conversion rates and significantly enhanced tolerance to H 2 O and SO 2 at 200–240 °C. These advancements are attributed to the synergistic interactions between Ce and Ti, which enhance redox properties, increase Lewis acid site density, and facilitate the Langmuir-Hinshelwood reaction pathway. In-situ DRIFTS and density functional theory (DFT) analyses revealed the mechanistic role of surface-active oxygen species and intermediate formation in promoting the SCR reaction. The findings provide valuable mechanistic insights and establish a scalable approach for the development of high-performance, environmentally friendly catalysts for industrial NO x removal.
研究领域:
催化化学
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2024
·
IF 5.3
Nan Liu,Qi Chen,Xianwu Jiang,Jie Chen,Lidong Zhang,Jiaying Pan,Haiqiao Wei,Xingqian Mao
This work presents a three-stage hybrid nanosecond discharge (NSD) and direct current (DC) discharge assisted n -C 5 H 12 /O 2 /N 2 ignition with lower discharge energy and higher energy efficiency. The reaction rate coefficients between O 2 (a 1 Δ g ) and n -C 5 H 12 are updated by mass/Master equation simulation. The promotive ignition enhancement via reaction channel O 2 (a 1 Δ g ) + n -C 5 H 12 → C 5 H 10 + H 2 O 2 in the hybrid NSD/DC discharge is demonstrated. The results show that the ignition delay time of the three-stage hybrid plasma assisted ignition is 1–2 orders of magnitude shorter than that of the two-stage hybrid discharge when the reduced electric field strength in the DC discharge stage is over 10 Td. Meanwhile, the plasma-enhanced energy efficiency of three-stage hybrid discharge increases. This improved efficiency on ignition enhancement is due to the kinetic enhancement by the electronically excited species and radicals (O 2 (a 1 Δ g ), O( 1 D), N 2 (B) and O). The kinetic and thermal effects by plasma are effectively intergated to enhance ignition. However, more discharge energy deposited in the vibrationally excited states N 2 ( v ) in the two-stage hybrid discharge is less efficient on ignition enhancement due to the thermal contribution via vibrational-translational relaxation. In the aspect of NO x /N 2 O emissions, reduction efficiency of the three-stage hybrid discharge is two times higher than that of the two-stage hybrid discharge. By controlling the N/N( 2 D) production pathway e + N 2 → e + N + N( 2 D), the three-stage hybrid discharge reduces NO x and N 2 O production by 61.1 % and 90 %, respectively. The results show that the ignition delay time is non-monotonically dependent on the discharge pulse number. There exist optimal pulse number, reduced electric field and effective threshold power density of DC discharge to achieve maximum ignition enhancement and low NO x /N 2 O emissions. This study provides valuable insights into the use of NSD/DC hybrid discharge technology in advanced engines to achieve energy-efficient ignition enhancement and reduce NO x /N 2 O emissions.
研究领域:
能源科学
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环境科学
·
化学动力学
✓ 已验证
产品关联
DOI
高影响因子
Tungsten
·
2024
·
IF 5.6
Zhang Zhi-Qi,Yang Liu,Luo Wen,An Vladimir,Li Jing,Liu Bao-Dan
The design and synthesis of vanadium-based denitration catalysts with low-temperature activity pose significant challenges in the field of toxic gas catalysis. In this study, we have developed a novel approach to fabricate highly efficient V 2 O 5 -WO 3 /TiO 2 monolithic mesh catalysts for NO x reduction at low temperatures. First, TiO 2 nanosheets with strong adhesion and large surface area were grown on Ti mesh using plasma electrolytic oxidation technology and hydrothermal method. Then, super-small traces of WO 3 and V 2 O 5 active nano-species were subsequently deposited on TiO 2 nanosheets using the deposition–precipitation method. Compared to traditional ceramic-based V 2 O 5 -WO 3 /TiO 2 catalysts, our V 2 O 5 -WO 3 /TiO 2 monolithic mesh catalyst exhibits superior mechanical performance, excellent thermal conductivity, lower pressure drop, higher utilization of active components, and stronger synergistic effects. Significantly, the V 2 O 5 -WO 3 /TiO 2 monolithic mesh catalysts exhibited excellent low-temperature catalytic activity with 98% of NO x conversion at 220 ℃, and remarkable long-term SO 2 tolerance and water resistance in the selective catalytic reduction (SCR) of NO x with NH 3 . The SCR reaction of tiny V 2 O 5 and WO 3 active species supported on TiO 2 nanosheets directly demonstrated to follow the Eley–Rideal mechanism by in situ infrared spectra.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Progress & Sustainable Energy
·
2022
·Vol. 42
·期 2
·e13998
·
IF 2.824
Gang Liu,Zhitao Han,Jiawei Li,Zhen Wang,Shaosi Cheng,Yubin Liu,Jing Yu,Xinxiang Pan
Since it is difficult to deal with high-concentration nitrates in scrubbed wastewater onboard vessels, the application of traditional wet denitration technology is limited to some extent. Here a novel method for removing pre-oxidized NO x by using Na 2 SO 3 /THS composite solution is proposed with the aim to obtain high NO x absorption efficiency and low nitrate concentration in scrubbed wastewater simultaneously. The effects of Na 2 SO 3 concentration, THS concentration, NO x oxidation degree, coexistence of SO 2 and O 2 in flue gas, initial pH value and temperature of absorption solution on denitration performance were discussed in detail. The results showed Na 2 SO 3 could reduce NO x to nitrate, nitrite, and N 2 . The addition of THS could promote NO x absorption greatly by forming complexes with SO 3 2− . When initial NO x concentration was 1000 ppm with a NO x oxidation degree of 50%, O 2 concentration was 8%, Na 2 SO 3 and THS concentrations were 25 and 20 mmol/L, a NO x absorption efficiency of 87% could be achieved, while nitrate and nitrite concentrations were 32.97 and 14.19 mg/L, respectively.
研究领域:
环境工程
·
海洋工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xiaodi Li,Shan Ren,Lian Liu,Xiangdong Xing,Lin Chen,Jiangling Li,Jian Yang,Qingcai Liu
The serious deactivation of denitration catalysts caused by heavy metals still a thorny issue in the practical application of selective catalytic reduction of NO x with NH 3 . Herein, we proposed a novel anti-poisoning strategy by designing SO 4 2− /ZrO 2 superacid supported CeO 2 /ZrO 2 catalyst, and the effect of SO 4 2− /ZrO 2 supported CeO 2 /ZrO 2 for PbO-resistance NO x catalytic reduction was investigated. It was worthy to note that the introduction of solid superacid SO 4 2− /ZrO 2 significantly enhanced catalytic performance over the entire temperature range, with an exceptionally high NO x removal efficiency over 98 % during 250–500 °C. When 2 wt% PbO was deposited on the fresh catalyst, the catalytic activity of CeO 2 /ZrO 2 catalyst decreased obviously, while CeO 2 /ZrO 2 -S catalyst can still maintain a higher NO x conversion over 90 % from 275 to 500 °C. The characterization results confirmed that the introduction of solid superacid SO 4 2− /ZrO 2 enhanced the surface acidity and promoted the transformation from Ce 4+ to Ce 3+ . The results of in situ DRIFTS implied that the Eley-Rideal (E-R) mechanism was obeyed over CeO 2 /ZrO 2 catalyst, and both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms were followed over CeO 2 /ZrO 2 -S catalyst in the SCR process. With regard to poisoned catalysts, the NH 3 adsorption was inhibited to some extent, while the reaction mechanism wasn’t changed by PbO poisoning.
研究领域:
催化
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Dongli Li,Yinan Dong,Hua Zhang,Dagang Liu,Zhituo Geng,Chenxi Li,Hao Li,Jiayao Zhou,Zhipeng Li,Hai Lin,Weitian Zhang,Shengze Yu,Shuyan Yu,Congju Li,Yongping Huang,Jingkun Jiang,Zehui Li
Nitrogen oxides (NO x ) monitoring requires sensor platforms that deliver ppb-level sensitivity, ambient-temperature operation, and molecular discrimination. However, rapid and selective NO x detection at room temperature remains elusive. Although 2D transition metal carbides/nitrides (MXenes) show promise in chemiresistive sensing, their susceptibility to ambient degradation and poor selectivity limit practical deployment. Here, a room-temperature NO x sensor is developed by epitaxially growing Hofmann-type metal–organic frameworks (Ni-pyz) on oxygen-terminated monolayer large-size MXene (Ti 3 C 2 T x ). The Ni-pyz/Ti 3 C 2 T x heterostructure exhibits enhanced sensitivity (4.8 and 5.5 times compared to Ti 3 C 2 T x ) and low detection limits (8.8 and 6.9 ppb) for NO and NO 2 , along with high selectivity and good stability (>85% response after 8 weeks). The enhanced sensitivity results from electronic coupling between the Ti 3 C 2 T x and Ni(CN) 4 , promoting charge transfer with NO x . The improved selectivity arises from the pore confinement effect of Ni-pyz and the specific adsorption of NO x through Lewis acid-base interactions with open Ni sites. Importantly, the dynamic response of Ni-pyz/Ti 3 C 2 T x closely mirrors that of a trace-level chemiluminescence NO x analyzer at low NO x concentrations, enabling high-temporal-resolution, long-term atmospheric monitoring. This functional strategy overcomes the insufficiency of MXene-based gas sensors, paving the way for the development of high-performance sensors.
研究领域:
材料科学
·
纳米技术
·
化学传感
·
环境监测
·
金属有机框架（MOFs）
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Shuai Guo,Lidong Liu,Xin Guo,Tiecheng Liu,Xingcan Li,Guangyu Li
Municipal sewage sludge poses environmental and health risks, and thus, requires proper disposal using pyrolytic techniques. However, these techniques are hindered by the production of NH 3 and HCN (NO x precursors) by the sludge. Hence, a comprehensive understanding of NH 3 and HCN formation during sludge pyrolysis is required to minimize its NO x footprint. As sludge N mainly occurs in proteins forms, its transformations can be modeled using amino acids. Here, we aimed to the study the mechanism by which carbohydrates influence the formation of NO x precursors during sludge protein pyrolysis at different temperatures using glutamic acid , tyrosine, and histidine as protein models and cellulose and lignin as carbohydrate models. During pyrolysis, the release of NH 3 and HCN was promoted by high temperatures and inhibited by carbohydrates. Despite this inhibitory effect, the results suggested that the release of NH 3 should be considered for samples rich in aliphatic amino acids. For glutamic acid and tyrosine, NO x precursor formation was inhibited by N fixation in coke under the action of volatiles produced during carbohydrate pyrolysis. For glutamic acid, adding cellulose and lignin increased the coke-N content by 25.32% and 44.73% at 700 ℃. For histidine, this effect was ascribed to the ring-opening reactions induced by the free radical products of carbohydrate decomposition and the enhanced transfer of N-containing compounds to tar after ring-opening recombination. Further, heterocyclic-N within tar increased to 69.12% due to lignin-histidine interactions at 700 ℃. The results of this study can assist in regulating sludge protein pyrolysis intended for minimizing the production of NO x precursors.
研究领域:
环境科学
·
化学工程
·
废物管理
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Yonglong Li,Wenming Liu,Ran Yan,Jian Liang,Tao Dong,Yangyang Mi,Peng Wu,Zheng Wang,Honggen Peng,Taicheng An
A series of hierarchical three-dimensionally ordered macroporous Fe 10-x V x binary metal oxides (3DOM-Fe 10-x V x ) catalysts were designed and synthesized for selective catalytic reduction of NO x from marine diesel engine exhaust. The physical-chemical performance of the 3DOM-Fe 10-x V x catalysts were subjected by various techniques and found that the 3DOM-Fe 10-x V x with the Fe to V atomic ratio of 9.0/1.0 exhibited a wider active temperature window, better soot resistance performance compared with the conventional Fe 9.0 V 1.0 catalyst due to its special 3DOM structure. Even when simultaneously exposed to the soot and high concentration of sulfur dioxide reaction feeds, the 3DOM-Fe 9.0 V 1.0 catalyst also displayed superior catalytic activity. Interestingly, we found that the soot had a reduction activity for NO x at high reaction temperature, which can effectively extend its active temperature window. The 3DOM-Fe 10-x V x catalysts prepared in this work could be potentially a good candidate for the cargo ships de NO x catalysts to satisfy the more stringent exhaust emission rules.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Peng Sun,Rui-tang Guo,Shu-ming Liu,Shu-xian Wang,Wei-guo Pan,Ming-yuan Li,Shuai-wei Liu,Jian Liu,Xiao Sun
CeSmOx mixed oxide catalysts supported on TiO 2 prepared by coprecipitation method were used for selective catalytic reduction of NOx with NH 3 . The results showed that the addition of Sm could effectively enhance the low-temperature SCR activity and SO 2 /H 2 O resistance of Ce/TiO 2 catalyst, and the appropriate mole ratio of Sm to Ce was 0.3. Characterization results indicated that the introduction of Sm could promote the formation of Ce 3+ and chemisorbed oxygen species on catalyst surface, which was favorable to the generation of NO 2 . Moreover, the doping of Sm could also promote the adsorption of NH 3 and NOx species on Ce/TiO 2 catalyst. The results of in situ DRIFT study revealed that the NH 3 -SCR reaction over CeSm/TiO 2 -0.3 catalyst was mainly controlled by the Langmuir−Hinshelwood mechanism in the low temperature range (<200 °C). Thereafter, the promoted NO oxidation and the enhanced NH 3 adsorption should play a major role for the excellent low-temperature SCR performance of CeSm/TiO 2 -0.3 catalyst.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yu Zhang,Rui Wang
NH 3 ‑selective catalytic reduction as the fascinating technology for complete NO x removal, the key in practical applications is to explore advanced catalysts with high catalytic reactivity and stability at low temperature. Herein, a series of hollow spherical AMnO x (A = Ce, Cu, Ni) catalysts was fabricated by using carbon nanospheres as sacrificial template. Characterization analysis including XRD, ICP, BET, SEM, TEM, H 2 -TPR, NH 3 -TPD, XPS, in situ DRIFTS together with kinetic studies were applied to acquire knowledge of the morphological structure and surface features of the catalysts as-prepared. We also performed a comparative study on three samples with regard to their SCR activity at low temperatures. Notable, the catalytic activity of the NiMnO x catalyst (95.9 %) was vastly superior to that of the CeMnO x (85.4 %) and CuMnO x (30.5 %) at 100 °C. This enhanced low-temperature activity of NiMnO x are correlated against hollow structure with more active sites, wider pore distribution, higher surface Mn content and the enhancement in surface acidity and reducibility. Even with 5 vol% H 2 O in the reaction gas fraction, the catalytic performance of NiMnO x hollow spheres was superior to the other two catalysts. Besides, it can be used for six consecutive runs without suffering a substantial activity loss. Additionally, the impact of various crucial process variables, including space velocity, H 2 O, SO 2 , and metal poisons, on the denitrification efficiency of NH 3 -SCR was examined. The current researches have a positive guiding role in the development of high-efficiency low-temperature NH 3 -SCR denitrification catalysts to boost NO x degradation.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2012
·
IF 4.98
Xiaoyan Wang,Zuoming Zhou,Guohua Jing
Magnetic poly(styrene–glycidyl methacrylate) porous microspheres (MPPM) with high magnetic contents were prepared by surfactant reverse micelles and emulsion polymerization of monomers, in which the well-dispersed Fe 3 O 4 nanoparticles were modified by polyethylene glycol (PEG) and oleic acid (OA) respectively. The characterizations showed that both of the OA–MPPM and the PEG–MPPM were ferromagnetic, however, the OA–MPPM was used to immobilize the bacteria for more advantages. Therefore, the effects of monomer ratio, surfactant, crosslinker and amount of Fe 3 O 4 on the structure, morphology and magnetic contents of the OA–MPPM were investigated. Then, the OA–MPPM was utilized to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium for Fe(III)EDTA reduction applied in NO x removal. Compared with free bacteria, the immobilized FD-3 showed a better tolerance to the unbeneficial pH and temperature conditions.
研究领域:
环境科学
·
微生物学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Jingjing Liu,Mengyuan Zhang,Diru Liu,Yunbo Yu,Guangyan Xu,Hong He
Ammonia selective catalytic reduction (NH 3 -SCR) of nitrogen oxides (NO x ) is a widely adopted method for controlling NO x emissions. However, achieving superior low-temperature activity while maintaining high N 2 selectivity over a broad temperature range remains a major challenge. In this study, a novel mesoporous manganese–titanium–aluminum (Mn-Ti-MA-S) composite oxide catalyst was synthesized by a modified evaporation-induced self-assembly method. The incorporation of Mn and Ti into mesoporous alumina (MA) framework significantly optimized the redox-acidic properties of the Mn-Ti-MA catalyst, with Mn in a highly dispersed state with fully exposed microcrystalline structures. Subsequent sulfur treatment further transformed the Lewis acid sites into Brønsted acid sites, shifting the reaction pathway from a Lewis acid site-dominated to Brønsted acid site-dominated mechanism. This strategy successfully overcame the conventional trade-off between low-temperature activity and high-temperature N 2 selectivity in NH 3 -SCR catalysts. Consequently, the optimized Mn-Ti-MA-S catalyst exhibited excellent catalytic performance, achieving both NO x conversion and N 2 selectivity above 90 % over a wide temperature range (104–400 °C). This work highlights a synergistic strategy that integrates redox and acid sites engineering with reaction pathway regulation, enabling the development of highly efficient NH 3 -SCR catalysts.
研究领域:
环境催化
·
材料科学
·
化学工程
·
大气污染控制
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）