APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Jiaqi Li,Mingfei Wang,Jiamin Qi,Xueqian Wang,Langlang Wang,Fei Wang,Kai Li,Yixing Ma,Ping Ning
Hydrogen cyanide (HCN), a common toxic and hazardous air pollutant in industrial exhaust, catalytic hydrolysis of HCN has been the focus of air pollution control research. In this study, a catalyst material (La-TiO 2 ) with high catalytic hydrolysis activity for HCN was obtained by loading La 2 O 3 on the TiO 2 surface, which could realize the complete conversion of HCN at 150 °C with high selectivity of NH 3 and CO 2 . The relevant characterization confirms that La 2 O 3 can be uniformly distributed on the TiO 2 , which can adjust the acid-base structure of the catalyst surface and induce the generation of multi-hydroxyl structures in TiO 2 . On this basis, the combination of in-situ technique and density functional theory (DFT) calculations confirmed that the loading of La 2 O 3 prompted the La-TiO 2 catalyst to activate H 2 O to generate surface hydroxyl groups (-OH), which further enriched the hydroxyl groups on TiO 2 and substantially improved the hydrolysis activity and NH 3 selectivity of the catalyst. And the study confirms that the hydroxyl-rich environment easy combine with the reaction intermediate (formic acid) to generate CO 2 and H 2 O, which accelerated the reaction rate, thus improving the conversion efficiency of HCN and lowering the catalytic conversion temperature. In addition, O 2 can continuously consume the remaining hydrogen atoms after the dissociation of H 2 O to generate hydroxyl groups again, thus effective enhancing catalyst stability. This study provides new theoretical support for the catalytic hydrolysis of HCN and new insights and ideas for the design and development of catalysts for the catalytic hydrolysis of HCN.
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
RSC Advances
·
2016
·Vol. 6
·期 95
·92943-92952
·
IF 3.289
Henghui Huang,Qi Yao,Hualin Chen,Bailing Liu
In order to improve the scale inhibition efficiency of existing scale inhibitors for industrial water and to reduce the phosphorus pollution of water bodies, a new type of scale inhibitor with a hyper-branched structure has been developed in this study. First, an AB′ type of functional monomer (AMA) was synthesized from maleic anhydride (MAH) and propylene glycol, then copolymerized with monomer B (MAH) through radical polymerization, resulting in a hyper-branched polycarboxylic acid. The synthesis conditions, such as reaction temperature and time, monomer ratio and initiator dosage, have been investigated for obtaining the expected hyper-branched polymer with good scale inhibition performance. The scale inhibition efficiency of the obtained products was determined according to their resistance to the crystallization of calcium sulfate and calcium carbonate under the optimal application conditions. The experimental results show that the hyper-branched polycarboxylic acid provides a scale inhibiting efficiency for CaCO3 and CaSO4 as high as 95.2% and 92.3%, respectively. In addition, XRD analysis showed that the good scale inhibition of the hyper-branched polycarboxylic acid is attributed to its ability to inhibit and destroy the formation of crystals, changing the crystal forms of the calcium scale. This conclusion indicates that the prepared hyper-branched polycarboxylic acid has great application potential in the treatment of industrial water.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Results in Chemistry
·
2025
·
IF 4.2
Hui Wang,Haoliang Wang,Siyamak Shahab,Hezhang Cheng,Mikhail Atroshko,Xianpeng Wang,Meng Ye
The widespread presence of antibiotic residues in aquatic environments, resulting from the extensive use of antibiotics in livestock and aquaculture, has driven the search for effective remediation methods. Adsorption, particularly using biochar, has emerged as a promising approach. In this study, rice straw-derived biochar (denoted as B5) modified with phosphoric acid (H 3 PO 4 -modified B5, PB5) and potassium hydroxide (KOH-modified B5, KB5) at the same concentration was investigated for ciprofloxacin (CIP) adsorption. PB5 exhibited a maximum Langmuir adsorption capacity of 25.6 mg/g for CIP, surpassing KOH-modified (8.77 mg/g) and unmodified biochar (3.71 mg/g). The optimized pH for adsorption was 3.0–7.0, where electrostatic interactions and hydrogen bonding dominated. Characterization revealed that acid-base modification altered the surface morphology, pore structure, and functional groups of biochar. PB5 exhibited a rougher surface, increased porosity, and enhanced oxygen-containing functional groups, while KB5 had a more pronounced increase in large specific surface area (SSA). Adsorption experiments indicated a multistage process involving chemisorption, external diffusion, and intraparticle diffusion. The pseudo-second-order model and the Freundlich isotherm best described the adsorption behavior, indicating chemisorption-dominated non-homogeneous adsorption. Density Functional Theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) analysis identified the -COOH group on biochar as the main active site for CIP adsorption, with a strong dual-force interaction. pH and anion studies showed that pH affected adsorption via electrostatic interactions, and divalent anions, especially SO 4 2− , inhibited adsorption, more so for PB5 due to its larger pore size. This study elucidates the distinct adsorption mechanisms of acid and alkali-modified biochar for CIP, providing valuable insights for the design and optimization of biochar for antibiotic removal in water treatment, Further research should explore diverse antibiotic models and advanced research tools to address real-world environmental challenges.
研究领域:
环境科学
·
水处理技术
·
污染物修复
·
材料科学
·
抗生素去除
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 7
·期 1
·213-221
·
IF 5.287
Xiaolong Liu,Junlin Zeng,Wenbo Shi,Jian Wang,Tingyu Zhu,Yunfa Chen
In this work, ruthenium-based bimetallic catalysts of the formula Ru–5M/TiO2 (M = Mn, Co, Ce, Cu, Fe) were prepared and evaluated in benzene oxidation, and Ru–5Co/TiO2 exhibited the lowest complete oxidation temperature (220 °C), demonstrating Co3O4 as the best dopant. The influence of the Ru and Co contents on the catalytic activity was also studied, and 1 wt% Ru and 5 wt% Co3O4 were confirmed. Water vapor showed an inhibition effect on benzene oxidation at 210 °C, whereas the catalytic efficiency was barely influenced at a higher temperature (230 °C). STEM analyses revealed that Ru–Co bimetallic species showed similar distributions on the catalytic surface. Based on the correlation of the catalytic results with various characterization techniques, the synergistic effect between Ru and Co was well demonstrated, and a four-step transformation in the oxidation process was concluded. Besides, systematic in situ FTIR studies for benzene oxidation over Ru/TiO2, Co/TiO2, and Ru–5Co/TiO2 were conducted and compared, and many organic intermediates were observed in the in situ FTIR spectra. Accordingly, the reaction mechanism for benzene oxidation over the Ru–Co bimetallic catalyst was proposed.
研究领域:
环境化学
·
催化科学
·
有机污染物降解
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jian-jun Lian,Meng Wu,Hong-yan Wu,Yan-ting Liu,Qing Xu,Man-jun Miao,Jian-hua Yang,Ke-ke Mao,Bo Chen,Feng Xue,Qiao-ping Kong,Ming-hao Shang,Xiu-ling Li
The significant increase in demand for molybdenum (Mo) resources has led to excessive molybdate (Mo(VI)) content in water, posing a challenge to the innovation of Mo(VI) removal technology in water bodies. Nanoscale iron sulfide (FeS) has an important effect on the environmental behavior of Mo(VI) in aquatic solutions. To address the issue of easy agglomeration and poor stability of FeS, zirconia sol-modified nanoscale iron sulfide (Zr-FeS) was synthesized, and the adsorption behavior of Zr-FeS on Mo(VI) from diverse aquatic solutions was also investigated in this study. The results showed that the removal rate of Mo(VI) was increased from 28.60% to 78.32% within pH value of 7.0 when Zr/Fe molar ratio was elevated from 0 to 0.5. Moreover, the Mo(VI) adsorption efficiency by Zr-FeS was closely related to pH values, and acid conditions were beneficial for Mo(VI) adsorption. The pseudo-second-order model demonstrated a better fit to the data compared to other models. The maximum adsorption capacity of Zr-FeS towards Mo(VI) value calculated by Langmuir isotherm model was 118.48 mg/g at 298 K. The thermodynamic analysis revealed that the adsorption process of Mo(VI) was endothermic, entropically favorable, and spontaneous in nature. Competing anions (e.g., PO 4 3– , HCO 3 – , and SO 4 2– ) partially inhibited the adsorption process of Mo(VI) by Zr-FeS. While the process was less affected by dissolved oxygen and aging. The results of Fourier-transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and density functional theory (DFT) calculations revealed that the main mechanisms for Mo(VI) removal were hydrogen bonding, electrostatic interaction and surface complexation. The high stability and fast adsorption rate indicated that Zr-FeS was a promising material to remove Mo(VI) from the aquatic solutions.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 2
·400
·
IF 2.847
Xiaohua Cao,Jichang Lu,Yutong Zhao,Rui Tian,Wenjun Zhang,Dedong He,Yongming Luo
Praseodymium (Pr)-promoted MCM-41 catalyst was investigated for the catalytic decomposition of methyl mercaptan (CH3SH). Various characterization techniques, such as X-ray diffraction (XRD), N2adsorption–desorption, temperature-programmed desorption of ammonia (NH3-TPD) and carbon dioxide (CO2-TPD), hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectrometer (XPS), were carried out to analyze the physicochemical properties of material. XPS characterization results showed that praseodymium was presented on the modified catalyst in the form of praseodymium oxide species, which can react with coke deposit to prolong the catalytic stability until 120 h. Meanwhile, the strong acid sites were proved to be the main active center over the 10% Pr/MCM-41 catalyst by NH3-TPD results during the catalytic elimination of methyl mercaptan. The possible reaction mechanism was proposed by analyzing the product distribution results. The final products were mainly small-molecule products, such as methane (CH4) and hydrogen sulfide (H2S). Dimethyl sulfide (CH3SCH3) was a reaction intermediate during the reaction. Therefore, this work contributes to the understanding of the reaction process of catalytic decomposition methyl mercaptan and the design of anti-carbon deposition catalysts.Keywords:rare earth;MCM-41;CH3SH decomposition;stability;reaction mechanism
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
RSC Advances
·
2015
·Vol. 5
·期 25
·19048-19057
·
IF 3.84
JiaQin Sun,Wei Wei,YaZhen Xu,JieHao Qu,XiangDong Liu,Takeshi Endo
Five commercially available amines: m-phenylenediamine (A1), m-xylylenediamine (A2), isophorone diamine (A3), trimethylhexamethylenediamine (A4), and 4,4′-diaminodiphenyl sulfone (A5), were examined as nucleophilic hardeners for bis-benzoxazine monomers based on aniline paired with bisphenol-A (BA-a) or bisphenol-F (BF-a). The reactivities and reaction mechanisms of their mixtures with BA-a were investigated using FTIR and NMR spectroscopy, DSC, and HPLC techniques. It was found that BA-a rapidly cured with the amines upon heating at 120 °C or 150 °C. The cure rate was similar to the amine/epoxy curing process in practical uses, and significantly faster than the ring-opening polymerization of bulk BA-a. The possible reaction mechanism was supported by the experimental results and includes three successive steps: (i) nucleophilic substitution at the carbon atom (O–C–N) in the oxazine ring by the amine, (ii) thermal decomposition of the resulting aminomethanaminium structure, and (iii) electrophilic addition of the newly formed iminium ion with the aromatic ring to form stable aminomethylphenol structures. These findings are helpful to improve the thermosetting resins in terms of their chemical structure, material properties, and processability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Shunan Zhang,Xiaofang Liu,Zilong Shao,Hui Wang,Yuhan Sun
Direct CO 2 hydrogenation to ethanol is one of the promising and emerging routes for the transformation of CO 2 into value-added chemicals, but it remains a major challenge because of low ethanol selectivity and catalytic stability. In this work, Na-promoted cobalt catalysts supported on different materials (Al 2 O 3 , ZnO, AC, TiO 2 , SiO 2 , and Si 3 N 4 ) were evaluated to elucidate the effects of supports. The SiO 2 - and Si 3 N 4 -supported catalysts exhibited efficient generation of ethanol with 18% CO 2 conversion and 62% selectivity in the alcohol distribution at 250 °C, whereas CH 4 was predominantly produced on other supported catalysts. Characterization results indicated that the Co 2 C active phase only remained intact on SiO 2 and Si 3 N 4 supports during reaction and exhibited excellent durability for 300 h, which was attributed to the existence of a strong metal–support interaction (SMSI) obtained by Si O Co bond formation. In situ DRIFTS results revealed that CO produced on Co 2 C inserted into CH x intermediates to form ethanol. Moreover, CO as the reactive intermediate could induce the regeneration and reconstruction of decomposed Co 2 C on the surface for catalytic sustainability.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Junhui Liu,Guanghui Zhang,Xiao Jiang,Junhu Wang,Chunshan Song,Xinwen Guo
Iron-based catalysts have been widely used to synthesize value-added hydrocarbons through CO 2 hydrogenation. Fe carbide, Fe 5 C 2 , was proposed as the active phase responsible for C C coupling during the chain growth. However, the reaction mechanism over iron-based catalysts is still under debate due to the presence of multiple phases of Fe species. In this work, Fe 5 C 2 and K-modified Fe 5 C 2 were prepared and used to study the relationship between the Fe phase, catalytic performance and reaction pathways. CH 4 and CO selectivities of 46.1 C-mol% and 2.8 C-mol% were obtained on Fe 5 C 2 at a CO 2 conversion of 49.8 %, with the main hydrocarbon products being alkanes. With the addition of the promoter K, the C 2 -C 4 = selectivity increased to above 38.0 C-mol%, and the selectivity to C 5+ hydrocarbons increased to 23.9 C-mol% at a similar CO 2 conversion. CH 4 and C 2+ hydrocarbons formed through the CO 2 →CO→hydrocarbons (indirect) route over K-modified Fe 5 C 2 , whereas the direct hydrogenation route occurred on unmodified Fe 5 C 2 in addition to the indirect route of CO 2 to CO to hydrocarbons through Fischer-Tropsch synthesis (FTS) processes. This work offers insights in direct CO 2 hydrogenation over Fe 5 C 2 and Fe 3 O 4 -Fe 5 C 2 catalysts, which advances the understanding of the functions of active phases and reaction pathways of CO 2 hydrogenation over iron-based catalysts.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Huixin Zhou,Dingxun Ma,Lingwen Dai,Yichao Wang,Xiaoling Ren,Xiaozhen Liu,Xumin Li,Haijiao Xie,Xinqian Shu
Quartz (Qtz) and kaolinite (Kln) are the main siliceous minerals in coal gangue (CG), which can be converted into effective silica by mechanical activation and improve the utilization efficiency of CG in turn. This study aimed to analyze and reveal the reaction mechanism of siliceous minerals in CG under mechanical activation surface modification by experiments and DFT calculations. We showed that increasing the rotational speed and m(Al 2 O 3 /SiO 2 ) stoichiometric ratio simultaneously boosted the activation ratio of siliceous minerals, up to 3.91 %. Mechanical activation promoted the formation of oxygen vacancy structures on siliceous minerals surfaces, which aligned with the system’s activation capacity. The Exp3P2 polynomial function model best described the relationship between the rotational speed and the activation ratio of different siliceous minerals. The oxygen vacancy, S BET , rotational speed, milling temperature, m(Al 2 O 3 /SiO 2 ) stoichiometric ratio, total pore volume showed significant positive correlations with the activation ratio. First-principles calculations revealed that the oxygen defect formation energy of Kln (5.17 eV) was slightly smaller than Qtz (5.27 eV), Kln was more likely to form oxygen defects than Qtz in mechanically activated reaction. This research contributes to understanding the mechanical activation of CG into effective silica, enhancing its potential for the graded and quality-based utilization.
研究领域:
材料科学
·
矿物加工工程
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2024
·Vol. 9
·期 3
·728-739
·
IF 3.4
Tongtong Wu,Weili Gao,Jiehe Zhang,Mingxu Hao,Shiyu Zhang,Haisheng Tao
As a typical antibiotic, tetracycline is ecotoxic and prone to bacterial resistance, producing superbugs and causing a public ecological crisis, thus raising the need to eliminate tetracycline from the aqueous environment. In this work, magnetic catalyst Fe3O4@HKUST-1 was prepared for catalyzing the degradation of tetracycline by persulfate. X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry were used to characterize the catalyst, and the results show that the catalyst had good crystallinity and magnetic properties. Tetracycline removal in the Fe3O4@HKUST-1/persulfate system reached 84.80%, and the catalyst was easily recovered from the solution due to its good magnetic properties. Mechanism analysis revealed that the non-radical pathway was the main degradation channel in the Fe3O4@HKUST-1/persulfate system, and 1O2 was the main reactive oxygen species generated from Ov on the surface of the Fe3O4@HKUST-1 catalyst. Tetracycline degradation was achieved by hydroxylation, demethylation, decarbonylation, dehydroxylation and the cleavage of C–N bonds. This finding holds significant value in further comprehension of the catalytic activation mechanism of metal–organic frameworks derivatives on persulfate and provides novel ideas for efficient water treatment technology development.
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SYNTHESIS-STUTTGART
·
2020
·Vol. 53
·期 07
·1341-1348
·
IF 2.675
Xinxin Zhao,Lin Guo,Chao Yang,Wujiong Xia
A highly regioselective [3+2] cyclization of alkenes with 2-iodoanilines under the irradiation of UV light is described. This general, metal-free strategy facilitates the direct preparation of 2-mono-/disubstituted indolines as well as spiroindolines through alkene carboamination in one step. Mechanistic studies suggested that the photochemical protocol proceeded via a radical pathway.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）