ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Weiting Yu,He Jiang,Jinhui Fang,Shuang Song
Reducing the Pd loading on electrodes is critical in the electrocatalytic hydrodechlorination (EHDC) of chlorinated organic compounds (COCs). The EHDC reaction of COCs on Pd involves three steps: H* formation, H* adsorption, and dechlorination. It has been established that the initial hydrogen evolution reaction (HER) occurs on Pd0 and the dechlorination steps occur on Pd2+. A strategy is proposed to design new electrodes by adding a reducible HER-active interlayer to replace Pd0, fulfilling the responsibility of producing hydrogen, and to facilitate the formation of more Pd2+ for following C–Cl bond cleavage. Keeping the atomic hydrogen adsorption energy on the Pd/interlayer similar to that on pure Pd is also necessary for H* adsorption as well as to maintain a high EHDC activity. For the first time, the NiCo2O4-interlayer-modified Pd/Ni-foam electrode was applied in the EHDC of COCs, which enhanced the EHDC efficiency to 100% within 90 min and reduced 88.6% of Pd consumption. The Pd/NiCo2O4/Ni-foam electrode with enhanced EHDC activity was also observed with almost 100% product selectivity and good stability. A synergistic mechanism is proposed for the enhanced EHDC activity on the Pd/NiCo2O4/Ni-foam. This work offers a simple and useful strategy to design robust electrocatalysts for the EHDC of COCs.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Bo Yang,Jiaxing Zhang,Yunfei Zhang,Shubo Deng,Gang Yu,Jinhua Wu,Hong Zhang,Jianhong Liu
The low-cost Al–Ni alloy particles could achieve high dechlorination activity for 2-chlorophenol (2-CP) with the addition of tetrasodium EDTA (EDTA-4Na) in this study. The species of chelating agent, pH values, and the dosages of chelating agent were investigated for their effects on dechlorination efficiency of 2-CP in solution. EDTA-4Na presented the highest promoting effect for Al–Ni alloy in dechlorination process compared with other chelating agents, which is closely correlated with the conditional stability constant ( K f ′ ) of chelates formed. The optimized result showed that 0.389 mM of 2-CP was completely dechlorinated into phenol using 10 g L −1 of Al–Ni alloy and 10 mM of EDTA-4Na at initial pH 11.0 within 45-min reaction. Recycling tests of the alloy particles showed that Al–Ni alloy coupling with EDTA in aqueous solution exhibited high dechlorination activity and stability before being exhausted. The maintenance of Al–Ni alloy activity for dechlorination was mainly attributed to the promoting effect of EDTA-4Na on Al corrosion, the inherent structure of alloy with Ni crystal homogeneously dispersing into Al substrate, and the change of its surface morphology with more active sites formed by EDTA corrosion.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Mei Ming,Yanlin Ren,Min Hu,Yun Zhang,Ting Sun,Yuling Ma,Xiaojing Li,Weidong Jiang,Daojiang Gao,Jian Bi,Guangyin Fan
Exploring MXenes as supports for synthesis of highly efficient catalysts are extremely important for hydrodechlorination of chlorophenols because of the acute toxicity and strong potential bioaccumulation of chlorophenols. We reported a facile strategy to synthesize Rh nanoparticles deposited on 2D alk-Ti 3 C 2 X 2 (X = O, F) (alk-Ti 3 C 2 X 2 for short) MXene, which was prepared through the removal of the Al layers of Ti 3 AlC 2 and post-treatment by alkalization. Modifying the Ti 3 C 2 X 2 support by alkalization triggered the substitution of surface fluorine groups with surface oxygen species. The changes in the surface chemistry of alk-Ti 3 C 2 X 2 effectively prevented particle aggregation to form well-dispersed Rh nanoparticles in small sizes with relative high metal dispersion, thereafter improving the hydrogen uptake capacity of the catalyst. Consequently, the Rh/alk-Ti 3 C 2 X 2 catalyst significantly enhanced the catalytic performance for the HDC reaction, which could be assigned to the large number of active components from small Rh nanoparticles. This strategy provides a basis for investigating the use of MXenes as supports to synthesize well-defined metal nanoparticles in 2D layered structures for potential applications.
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
APPLIED CATALYSIS A-GENERAL
·
2015
·
IF 3.942
Cen Tang,Yanxia Jin,Jiqing Lu,Xiaonian Li,Guanqun Xie,Mengfei Luo
A series of Mg catalysts supported on SiO 2 were prepared by an incipient wetness impregnation method and tested for gas phase dehydrochlorination of 1,1,2-trichloroethane. It was found that these catalysts were very active and selective for the reaction. The catalytic performance depended on the Mg loading rather than the Mg precursors as the catalysts using Mg(NO 3 ) 2 ·6H 2 O and MgCl 2 ·6H 2 O as the precursors showed the similar performance. A catalyst containing 10 wt.% of Mg showed the best performance with a steady state TCE conversion of 92% and cis -dichloroethene selectivity of 91%. Moreover, characterizations of the catalysts revealed the formation of Cl-containing Mg species on the surface during the reaction. The analyses of the compositions of the stable catalysts under working conditions indicated a Cl/Mg ratio of 1, suggesting that Mg(OH)Cl could be the active sites for the reaction.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Xuguang Li,Tong Li,Tong Zhang,Cheng Gu,Shourong Zheng,Haijun Zhang,Wei Chen
Nanoscale titanium dioxide (nTiO2) is one of the most widely used metal oxide nanomaterials. Once released into the environment, nTiO2 may catalyze abiotic transformation of contaminants and consequently affect their fate and effects. Here, we show that the overall catalytic efficiency of nTiO2 for the dehydrochlorination reaction of 1,1,2,2-tetrachloroethane, a commonly used solvent, depends on the crystalline phase and exposed facets of nTiO2, which significantly affect the adsorption capacity and surface catalytic activity of nTiO2. Specifically, under all three pH conditions tested (7.0, 7.5 and 8.0), the overall catalytic efficiency of eight nTiO2 materials (as indicated by the surface-area-normalized reaction kinetic constants) followed the order of rutile > anatase > TiO2(B). For anatase and TiO2(B) materials, the overall catalytic efficiency increased with the increasing percentage of exposed {001} and {010} facets, respectively. Crystalline phase and exposed facets significantly affected adsorption affinities of nTiO2, likely by modulating surface hydrophobicity of nTiO2. Crystalline phase and exposed facets also determined the activity of surface catalytic sites on nTiO2 by dictating the concentration and strength of surface unsaturated Ti atoms, as the deprotonated hydroxyl groups chemisorbed to these reactive Ti atoms served as bases to catalyze the base-promoted reaction.
研究领域:
环境科学
·
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Jia Deng,Enlai Gao,Feng Wu,Zhixiong You,Xiaozhong Li,Shuxian Gao,Li-Zhi Huang
Atomic hydrogen (H•) is highly reactive for the hydrodechlorination of trichloroethylene (TCE). In this work, we found that the coprecipitation of Ni 2+ and Fe 2+ at neutral pH led to an unprecedented catalytic generation of H•. The generated H• effectively dechlorinate TCE to nontoxic ethylene and ethane, and Fe 2+ is the only electron donor. The abundant adsorbed H• produced with a Ni/Fe ratio of 0.4 enhances hydrogen evolution reaction causing a low efficiency for hydrodechlorination. In contrast, the active absorbed H• is generated in the crystal lattice of Ni-Fe hydroxides with a Ni/Fe ratio of 3.0 causing highly efficient hydrodechlorination of TCE. This work not only reveals the mechanism of catalytic hydrodechlorination by Ni-Fe hydroxides at neutral pH, but also provides a novel approach to detoxify TCE in contaminated water using facile precipitated Ni-Fe hydroxides.
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
·
2022
·
IF 9.136
Yanju Chen,Chao Feng,Wenhong Wang,Zhi Liu,Junxi Li,Chenguang Liu,Yuan Pan,Yunqi Liu
Regulating the electronic structure of Pd catalyst for promoting electrocatalytic hydrodechlorination is promising but still challenging. Herein, we propose an electronic structure engineering for accelerating the hydrodechlorination process by desigining bimetallic Pd-Au alloy nanoparticles (ANs) with electron-rich Pd as high-efficiency electrocatalysts. The Pd 7 Au 3 ANs exhibits the highest electrocatalytic hydrodechlorination activity, the 4-chlorophenol hydrodechlorination efficiency reaches 98.35 % within 4 h, and the mass activity is 0.47 h −1 mg Pd −1 , which is 7.83 times as high as that of pure Pd nanoparticles. The experimental characterization and theoretical calculation reveal that Pd atoms “obtain” electrons and gold atoms “lose” electrons in Pd-Au ANs, resulting in the formation of electron-rich Pd, which promotes the desorption of the dechlorination product phenol and accelerates the renewal of active sites. This work provides an electronic structure engineering strategy of Pd-based electrocatalysts for electrocatalytic hydrodechlorination, which opens a new opportunity for rational design and construction of high-performance hydrodechlorination catalysts.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Li Gong,Jingting Chen,Guangming Zhan,Junning Zu,Hao Li,Feng He,Paul G. Tratnyek,Lizhi Zhang
The widespread application of zerovalent iron (ZVI) in water treatment and remediation has motivated research into modifications of the material that result in improved performance. The newest and most promising involves nitridation, but available methods for nitridation are not environmentally sustainable processes. Here, we demonstrate that mechanochemical molten-salt-assisted synthesis can be an effective method to produce surface-nitridated ZVI (sN-ZVI). This modification promoted the dechlorination rate of ZVI by up to 82-fold toward chlorinated ethenes and chloroform (CF). Enhanced conductivity of the nitridated shell boosts outward electron transfer from the iron core, while the exposed iron nitrides are efficient in activating the C–Cl bond of both trichloroethene and chloroform and facilitate electron-transfer-mediated C–Cl cleavage with an energy barrier of 0.20 eV, lower than that of iron oxides (0.78 eV). More importantly, sN-ZVI minimizes side hydrogen evolution and promotes deep dechlorination, thus preventing the formation of any toxic chlorinated intermediates, even in the case of highly chlorinated carbons such as tetrachloroethene and chloroform. sN-ZVI maintains its dechlorination performance even after 100 days of water aging, highlighting its great potential for field remediation applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Xin Ning,Yiyuan Lu,Heyun Fu,Haiqin Wan,Zhaoyi Xu,Shourong Zheng
Supported Ni catalysts on three mesoporous SiO2 supports (i.e., SBA-15, MCM-41, and HMS) were prepared using a solid-state reaction between Ni(NO3)2 and organic template-occluded mesoporous SiO2. For comparison, supported Ni catalysts on mesoporous SiO2 synthesized by the conventional impregnation method were also included. The catalysts were characterized by scanning electron microscopy, X-ray diffraction, UV–vis diffuse reflectance spectroscopy, N2 adsorption, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, transmission electron microscopy, and transmission electron microscopy–energy-dispersive X-ray. The catalytic properties of the catalysts were evaluated using gas-phase catalytic hydrodechlorination of 1,2-dichloroethane. The results showed that upon grinding Ni(NO3)2 with template-occluded mesoporous SiO2, strong coordination between Ni2+ and dodecylamine was identified in the Ni(NO3)2–HMS system. Additionally, the results of H2 temperature-programmed reduction revealed that NiO in calcined NiO/HMS was reduced at higher temperature than those in calcined NiO/SBA-15 and NiO/MCM-41, reflecting the presence of a strong interaction between NiO and mesoporous SiO2 in NiO/HMS. Consistently, the average particle sizes of metallic Ni were found to be 2.7, 3.4, and 9.6 nm in H2-reduced Ni/HMS, Ni/SBA-15, and Ni/MCM-41, respectively, indicative of a much higher Ni dispersion in Ni/HMS. For the catalytic hydrodechlorination of 1,2-dichloroethane, Ni/MCM-41 synthesized by the solid-state reaction method exhibited a catalytic activity similar to that prepared by the impregnation method, while higher catalytic activities were observed on Ni/HMS and Ni/SBA-15 than on their counterparts prepared by the impregnation method. Furthermore, a higher conversion was identified on Ni/HMS than on Ni/SBA-15 and Ni/MCM-41, highlighting the importance of template type for the preparation of highly dispersed metal catalysts on mesoporous SiO2.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
BULLETIN OF MATERIALS SCIENCE
·
2020
·Vol. 43
·期 1
·1-7
·
IF 1.392
Xiao Meng,Peng Yu,Pang Mengting,Hao Baicun,Wang Yujia,Zhang Yulian,Liao Yang,Mao Hui
Heterogeneous Pd catalysts were developed by immobilizing Pd nanoparticles (Pd NPs) onto plant polyphenol (bayberry tannin, BT) decorated γ-Al 2 O 3 . The abundant hydroxyls of plant polyphenols were capable of stabilizing the Pd NPs. Transmission electron microscopy observation confirmed that the Pd NPs with the diameter of 3.75 ± 0.5 nm were highly dispersed in the catalyst. The as-prepared Al 2 O 3 –BT–Pd catalysts were found to be highly active in mild hydrodechlorination (HDC) of 2,4-dichlorophenols (DCPs) using formic acid as a hydrogen source. The 2,4-DCPs were completely dechlorinated in 4 h at 30°C and under atmospheric pressure. During the catalytic HDC, the stabilizing capability of BT successfully prevented the leakage and aggregation of Pd NPs, thus ensuring a high cycling stability with stable and high catalytic activity. The Al 2 O 3 –BT–Pd catalysts were recycled six times, without obvious loss of activity. In the sixth cycle, the catalytic HDC yield still reached 98.29% under the same reaction conditions, superior to the control catalysts, including γ-Al 2 O 3 supported Pd NPs (Al 2 O 3 –Pd) and powdered activated carbon supported Pd NPs (AC–Pd). Furthermore, the Al 2 O 3 –BT–Pd also showed high activity in the mild catalytic HDC of 2,4,6-trichlorophenols and chlorobenzene derivatives. Our results demonstrated efficient catalysts to address the environmental issue of chlorophenol pollution.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Pengze Zhang,Zhaobin Jiang,Yanhong Cui,Guanqun Xie,Yangzhen Jin,Lingling Guo,Yiqi Xu,Qunfeng Zhang,Xiaonian Li
Gas phase catalytic process with the advantages of simply product separation and maximized atom economy, which was a green path used in industrial production. At present, heterogeneous dehydrochlorination catalysts are facing challenge of rapid deactivation caused by released HCl and carbon deposit. In this paper, a series of supported ionic liquid catalysts (SILCs) was synthesized by wet impregnation method and applied to 1, 1, 2-trichloroethane (TCE) dehydrochlorination to produce 1, 1-dichloroethylene (VDC). Tetraarylphosphonium chlorine was the active component with the unique acid resistance and the ability to dissolve coke, which determined the activity and stability of the catalyst. For 6%Tetraphenylphosphonium chloride (TPPC)/SiO 2 (260 °C, WHSV = 0.19 h −1 ), the conversion of 1, 1, 2-TCE was ＞99.5%, selectivity of VDC was 86%, and the catalytic activity remained stable within 1100 h. Herein, highly activity for dehydrochlorination was attributed to the strong hydrogen-bond basicity of Cl-, which was decided largely by the interaction between anion and cation of ionic liquid. The reaction mechanism was investigated using FTIR, XPS, TGA-MS, XRF, DFT calculation and two step elimination model induced by alkaline active center is proposed. Such catalysts provide a viable industrial solution to gas dehydrochlorination reaction and design of heterogeneous basic 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
ENERGY & FUELS
·
2018
·
IF 3.024
Yang Chen,Shuhua Zhang,Xiuxiu Han,Xu Zhang,Mengting Yi,Siyuan Yang,Dayang Yu,Weijun Liu
The catalytic effects of CuAl layered double hydroxide (CuAl-LDH) on dechlorination and carbonization of polyvinyl chloride (PVC) during pyrolysis were investigated. The thermal degradation and combustion behaviors were researched via thermogravimetric analysis (TGA) and cone calorimetry (CONE). The released gases were evaluated in detail by thermogravimetric analysis coupled with Fourier transform infrared spectrometry (TGA-FTIR). Subsequently, elemental analysis and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) were employed to fully characterize the solid residues. The results of TGA and CONE showed that the addition of CuAl-LDH brought about the PVC degradation earlier and the char residues increase significantly. Moreover, the results of TGA-FTIR, elemental analysis, SEM-EDS, and Raman analysis revealed that the existence of CuAl-LDH accelerated the dehydrochlorination and promoted the char formation of PVC. CuAl-LDH maybe a potential catalyst applied to treat PVC waste into carbon materials to realize material and chemical recycling, which possess tremendous environmental and economic benefits.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 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）