CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Chengzhi Wang,Fengyu Gao,Songjin Ko,Hengheng Liu,Honghong Yi,Xiaolong Tang
The presence of SO 2 in industrial flue gases will cause permanent deactivation of the catalyst active centre. Therefore, an effective method to improve the SO 2 resistance of manganese-based catalysts at low temperatures is urgently needed. In this work, a hierarchical porous nanowire structure catalyst was designed by the in situ self-assembly method to inhibit SO 2 adsorption. This hierarchical porous nanowire aerogel catalyst with great BET surface area and surface acidity exhibited NOx conversion above 90% at 100–400 °C. Notably, the NOx conversion of the MnCe-N catalyst was almost not inhibited by SO 2 (250 ppm) compared to the 33% decrease of the MnCe-P catalyst. On the MnCe-P catalyst, SO 2 has strong competitive adsorption with NH 3 and NO, and the stronger adsorption capacity of SO 2 inhibits the adsorption activation of the reaction gas and hinders the reaction proceeding through the L-H mechanism. Meanwhile, a large quantity of sulfate is formed on the catalyst surface, which prevents the active centre to participate in the redox reaction. The structure of nanowires enhances the number of acid sites, facilitates the adsorption and activation of NH 3 , and effectively inhibits the adsorption of SO 2 on the MnCe-N catalyst. Fewer sulfate species are generated and difficult to deposit and aggregate on the catalyst surface, as a result, the active centre is less affected by sulfate species. The stable adsorption of NH 3 -related species ensures reliable reaction on MnCe-N through the E-R mechanism. This work emphasizes the importance of hierarchically porous structures in improving the NH 3 -SCR performance and SO 2 resistance of monolithic catalysts, and provides new insights into the design of highly efficient and stable catalytic materials.
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ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Xiaobo Ma,Lijun Gao,Qiyu Zhang,Weibo Hua,Yating Zhang,Xinyang Li,Juan Yang,Shujiang Ding,Chao Hu
The traditional Haber-Bosch N 2 fixation process suffers from rigorous reaction conditions and massive CO 2 emission. By contrast, N 2 electroreduction by water to the direct production of NH 3 can be conducted at room temperature and atmospheric pressure, and thus has been attracting increasingly attention. Herein, we develop a nano-CaCO 3 template route for the synthesis of Fe, N co-doped porous carbon materials from zeolitic imidazolate framework-8 (ZIF-8). The Fe atoms are atomically dispersed in the skeleton of carbon and bonded with four nitrogen atoms . Interestingly, the morphology and pore structure of these carbons have notable effects on their performance for the electrocatalytic reduction of N 2 . With an optimized morphology and pore structure tuned by the addition of nano-CaCO 3 template, the ZIF-8 derived Fe, N co-doped carbon catalyst shows a Faradaic efficiency of 13.14% and a NH 3 yield as high as 13.01 µg h −1 mg cat −1 (−0.2 vs . reversible hydrogen electrode) for N 2 reduction reaction in 0.1 M KOH aqueous electrolyte . Morphology engineering strategy may open a new path to designing and synthesizing high-performance carbon-based catalysts for the electroreduction of N 2 to NH 3 .
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FOOD CHEMISTRY
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2022
·
IF 9.231
Zhisong Wang,Yuxuan Zhao,Di Wang,Xianglong Zhang,Menglei Xia,Ting Xia,Yu Zheng,Min Wang
To investigate the formation of typical melanoidin polymers, methylglyoxal (MGO) with NH 3 or alanine (Ala) was used to form coloured compounds, with glyoxal or acetone used as controls. The products were characterised using chromatography, mass spectrometry, and spectroscopy. Spectroscopic results showed that the coloured compounds formed were similar to melanoidins in food. GC-MS results showed that the MGO-based reaction generated similar volatile compounds using the Maillard reaction. Mass spectrometry showed that the molecular weights of structural units in the polymers were mainly 162, 169, and 176 Da, and these could be reassembled using the basic units derived from MGO alone or in combination with nitrogen. Hence, polymers recombined using basic structural units should be considered while determining melanoidin biomarkers. The preparation of coloured compounds using MGO with NH 3 can be used as a novel method to produce the control compounds for melanoidin after process optimization.
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PubMed
高影响因子
APPLIED THERMAL ENGINEERING
·
2022
·
IF 6.465
Zhenghao Jin,Shuhong Li,Runfa Zhou,Mengkai Xu,Weixue Jiang,Kai Du
Adding nanoparticles can enhance the mass and heat transfer of basic fluid, improving the coefficient of performance(COP) of the absorption refrigeration system(ARS). However, there are few experimental studies on the effects of absorption pressure and temperature on the absorption performance of nanofluid in an actual ARS. Therefore, the TiO 2 nanoparticles are added to the NH 3 - H 2 O – LiBr working fluid. The difference in ammonia mass fraction between the inlet and outlet solution of the absorber (Δ ε ' a ) is compared with when the solution is absorbed saturated (Δ ε a ). The results indicate that the Δ ε ' a and system COP increase when the absorption temperature decreases, the absorption pressure increases, or the TiO 2 mass fraction increases. The ratio Δ ε ' a /Δ ε a is used to evaluate the absorption efficiency of the nanofluid. The positive effects of nanofluid on the absorption efficiency and COP slightly increase when absorption temperature increases, but decrease when the absorption pressure is greater than 0.31 MPa. For all of our test groups, the greatest improvement in absorption efficiency is 85 %, and the largest improvement in COP is 13.7 %.
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JOURNAL OF CATALYSIS
·
2021
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IF 7.92
Yue Ma,Songqi Cheng,Xiaodong Wu,Tongxi Ma,Liping Liu,Baofang Jin,Minghan Liu,Jianbo Liu,Rui Ran,Zhichun Si,Duan Weng
To improve the hydrothermal durability of Cu-SSZ-13 selective catalytic reduction (SCR) catalyst, a thin Al 2 O 3 modification layer was coated on the external surface of Cu-SSZ-13 by a chemical liquid deposition (CLD) method. The high-temperature SCR activity of the Al-modified Cu-SSZ-13 can be maintained upon 750–800 °C hydrothermal aging, and over-oxidation of NH 3 is largely inhibited. Based on H 2 -TPR and EPR results, it is revealed that CuAl 2 O 4 -like species forms upon Al modification and converts further to CuAlO 2 -like species during aging, while the accumulation of CuO-like species is inhibited. The high affinity of Al-containing species ( i.e. , Al 2 O 3 and CuAl 2 O 4 -like species) with Cu(OH) 2 is suggested by DFT calculations, indicating that Cu(OH) 2 detached from ion-exchange sites are captured by Al to form CuAlO 2 -like species instead of CuO-like species. The passivation of detached Cu species by coated Al leads to somewhat weakened low-temperature SCR activity, but successfully preserves the high-temperature SCR performance upon aging, which can be applied to high-temperature SCR scenarios.
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Frontiers in Energy Research
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2020
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IF 2.746
Wang Ning,Song Qing-Song,Liu Wen-Jing,Zhang Jian
A new ringlike V2O3 architecture was successfully synthesized by a template-free hydrothermal method, and the sulfur ions-assisted central-etching mechanism of the ringlike structure was proposed. Herein, as a proof-of-concept experiment, taking V2O3 nanorings as non-noble-metal-free nitrogen reduction reaction (NRR) catalysts, they show desired electrocatalytic performance toward NRR under ambient conditions (maximum yield: 47.2 µg h−1 mgcat.−1 at −0.6 V vs. reversible hydrogen electrode, maximum Faraday efficiency: 12.5% at −0.5 V vs. reversible hydrogen electrode), which is significantly higher than those of noble metal-based catalysts.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
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IF 16.683
Jinxiu Zhao,Xuejing Liu,Xiang Ren,Xu Sun,Dongxu Tian,Qin Wei,Dan Wu
Electrochemical N 2 reduction is developing as an appealing carbon-neutral strategy for NH 3 artificial synthesis but seriously influenced by requiring high-efficiency electrocatalysts for the N 2 activation at ambient conditions. Here, we reported that defective-rich ZnS nanoparticles supported on reduced graphene oxide (DR ZnS-rGO) acts as a high-efficiency electrocatalyst for ambient N 2 -to-NH 3 conversion with excellent selectivity. In 0.1 M HCl, such DR ZnS-rGO presents a large NH 3 yield of 51.2 μg h –1 mg cat. –1 (−0.15 V vs . reversible hydrogen electrode, RHE) and a high faradic efficiency of 28.2 % (−0.10 V vs . RHE), as well as high electrochemical and structure stability. Isotopic labelling samples experiments reveal that the synthetic NH 3 directly arise from the supplied N 2 . Density functional theory calculations demonstrated that the engineering S vacancies in DR ZnS-rGO not only provide reaction sites for N 2 -to-NH 3 conversion but activate of N 2 molecules.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Pengfei Li,Dawei Shang,Wenhui Tu,Shaojuan Zeng,Yi Nie,Lu Bai,Haifeng Dong,Xiangping Zhang
Ammonia (NH 3 ) is one of the main reasons for the formation of aerosols. NH 3 pollution mainly comes from a large amount of emissions in industrial production. Ionic liquids (ILs), as a green solvent, can efficiently separate and recover NH 3 from industrial NH 3 -containing tail gas. In this work, novel protic ionic liquids (PILs) with hydrogen bond donating ability were designed and synthesized by incorporating six-membered N -heterocyclic compounds including pyridinium and piperidinium as cations. Three pyridinium-based PILs with single protic H showed higher NH 3 capacity with the maximum of 3.078 mol NH 3 /mol IL at 313.1 K and 0.10 MPa than the piperidinium-based PILs with double interaction sites. However, there was obvious reduction in NH 3 capacity for pyridinium-based PILs during absorption and absorption-desorption cycles. The reason is that the acidic protic H of cations of pyridinium-based PILs is easily stripped in supersaturated alkaline environment due to the smaller p K a of pyridine derivatives than that of NH 3 , forming the NH 4 + and volatile neutral pyridine derivatives. This work will provide useful guidance to the design of novel ILs used for efficient and reversible absorption of NH 3 .
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Nano Research
·
2020
·Vol. 13
·期 11
·2967-2972
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IF 8.183
Wei Peipei,Geng Qin,Channa Ali Imran,Tong Xin,Luo Yongsong,Lu Siyu,Chen Guang,Gao Shuyan,Wang Zhiming,Sun Xuping
To develop highly efficient electrochemical catalysts for N 2 fixation is important to sustainable ambient NH 3 production through the N 2 reduction reaction (NRR). Herein, we demonstrate the development of vanadium phosphide nanoparticle on V foil as a high-efficiency and stable catalyst for ambient NH 3 production with excellent selectivity. The high Faradaic efficiency of 22% with a large NH 3 yield of 8.35 × 10 −11 mol·s −1 ·cm −2 was obtained at 0 V vs. the reversible hydrogen electrode in acid solution, superior to all previously studied V-based NRR catalysts. Density functional theory calculations are also utilized to have an insight into the catalytic mechanism.
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AICHE JOURNAL
·
2020
·Vol. 66
·期 8
·e16253
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IF 3.519
Yongkang Cao,Xiangping Zhang,Shaojuan Zeng,Yanrong Liu,Haifeng Dong,Chun Deng
The emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH 3 due to their unique properties. However, the solid or highly viscous ILs are not suitable for traditional scrubbing. Therefore, an effective strategy was proposed by combining the protic ILs (PILs) with acidic H and low viscous ethylene glycol (EG) to form IL-based deep eutectic solvents (DESs) for NH 3 absorption. The results indicated that these PIL-based DESs not only have fast absorption rate, but also exhibit exceptional NH 3 capacity and excellent recyclability. The highest mass capacity of 211 mg NH 3 /g DES was achieved by [Im][NO 3 ]/EG with molar ratio of 1:3, and was higher than all the reported ILs and IL-based DESs, which was originated from multiple hydrogen bonding between acidic H and hydroxyl groups of the DESs and NH 3 . This work will provide useful idea for designing IL-based solvents for NH 3 separation applications.
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Advances in Materials Science and Engineering
·
2019
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IF 1.399
Zhuo Yao,Dianli Qu,Yuxiang Guo,Yujing Yang,Hong Huang
Novel catalysts with high activity for the selective catalytic reduction of NO with NH3 (NH3-SCR) at low temperatures are highly demanded. In this study, mixed-node metal-organic frameworks (MOFs), e.g. Mn@CuBTC with controlled Mn composition in Cu3(BTC)2, were fabricated using postsynthetic exchange method and their structural characteristics and catalytic performances for NH3-SCR reaction were assessed. A series of analyses in terms of structure, surface morphology, texture, and chemical state determined that Mn ions were successfully incorporated into the Cu3(BTC)2 crystal lattice as well as adsorbed on the walls of nanopores in the framework. The pore sizes can be finely tuned in the presence of Mn ions in the cages, which significantly suppressed water adsorption. The NH3-SCR activity of Mn@CuBTC exhibited nearly 100% NOx conversion rate in the temperature range (230–260°C). The superior NH3-SCR performance is attributed to the proper pore sizes, reduced water content, and the synergistic effect between manganese and copper ions in the MOF structure, which enhanced NH3 bound to the active Lewis sites.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Siqian Zhang,Cheng Zhang,Qiang Wang,Wha-Seung Ahn
A series of ZSM-5 catalysts were synthesized using fly ash from power plants and red mud from aluminum production in different weight ratios. The ZSM-5 was subsequently coimpregnated with Co and Mn and tested for the low-temperature selective catalytic reduction of NOx by NH3 (NH3-SCR). These catalysts were characterized by XRD, N2-adsorption isotherms, SEM, XPS, and H2-TPR. Among all the prepared catalysts, 5 wt % Co 10 wt % Mn/ZSM-5 had shown the best catalytic activity, with 98.8% conversion of NOx and 90.7% selectivity toward N2 at 150 °C. This is comparable to the performance of a similar ZSM-5 catalyst prepared using chemical reagents. The high ratio of Mn4+/(Mn4+ + Mn3+ + Mn2+) in the catalyst improved the NOx conversion, whereas the moderate redox property imparted by Co3+ led to high N2 selectivity. This catalyst also showed strong resistance against poisoning in 100 ppm SO2 and 5% H2O. This work demonstrates that effective NOx removal treatment with high N2 selectivity and sufficient stability for either cement plants or incinerators can be achieved by using a porous catalyst/support material produced from industrial solid wastes.
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