SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zijin Pang,Degang Li,Xinru Wang,Xin Huang,Yu-Shi He,Weimin Zhang,Lipeng Zhang
The electrocatalytic dichlorination (EHDC) shows a promising potential to degrade chlorinated phenols (CPs). It is also a green technology in reducing the corresponding hazardous impact on the environment. In this study, we constructed a catalytic structure which was Pd on a TiO 2 array with oxygen vacancies on carbon fibre paper substrate (Pd/TiO 2 /CFP) by a relatively mild route. Due to the presence of the oxygen vacancies, the resulting strong metal-support interaction (SMSI) effect has been identified which featured a redistribution of spatial charge in Pd/TiO 2 . The electron flow from the oxygen vacancies in the TiO 2 to Pd facilitated the adsorption of Pd with 4-chlorophenol (4-CP) and endowed the Pd metal with an improved chemical reaction kinetics even at a low Pd loading. Experimentally, we studied the dependence of pH, concentration of 4-CP, and working potential on the reaction conditions of EHDC. The results showed that the conversion of 4-CP reached 100 % within 180 min with an apparent rate constant of 2.9 × 10 -2 min −1 and the dominant product was phenol (P). The multi-cycle test illustrated that the Pd/TiO 2 /CFP electrode showed superior stability. The results also revealed that the comprehensive catalytic behavior was much better than those of the Pd/CFP and the TiO 2 /CFP electrodes. The density function theory (DFT) calculations indicated that 4-CP was more preferably absorbed on Pd/TiO 2 /CFP than Pd/CFP due to the SMSI assistance. This study provides a valuable guide in the preparation of precious metal-based electrodes for EHDC with a reduced loading and cost but without performance compromise.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Wei Guo,Yao Qin,Cheng Liu,Binbin Guo,Junhua Zou,Zenghong Xie,Ling Wu
This work reports the rapid and effective photocatalytic dechlorination of 3,3′,4,4′-trtrachlorobiphenyl (PCB77) with highly dispersed Pd nanoclusters loaded two-dimensional (2D) TiO 2 (B) nanosheets (Pd/TiO 2 (B)) under visible light irradiation, achieving a dechlorination efficiency of 100 % with H 2 O used as an H-donor source. The ultra-thin TiO 2 (B) nanosheets provide a good platform for studying the dechlorination intermediates/pathways of PCB77 at the molecular level. It is proved that the dechlorination of PCB77 is a stepwise process, in which chlorines at the para positions are much more susceptible than those at the meta positions due to the activation of the C Cl bond in the presence of Pd nanoclusters. Furthermore, in-situ FTIR results of D 2 O absorption suggest that the TiO 2 (B) nanosheets with abundant surface defects greatly promote the activation of water molecules via the formation of surficial complexes by hydrogen bonds. Finally, a synergistic mechanism is proposed for photocatalytic dechlorination of PCB77 over Pd/TiO 2 (B). The study provides an efficient method for complete dechlorination of PCB77 and an in-depth understanding photocatalyzed dechlorination reaction mechanism at the molecular level, which may extend to other photocatalytic dehalogenation reactions of halogenated pollutants.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Jing Wang,Sisi Fan,Hongmin Duan,Jinming Xu,Yanqiang Huang
Carbon spheres with hierarchical pore structure were successfully synthesized by using strongly basic anion exchange resins exchanged with silicate, followed by pyrolysis in an inert atmosphere and etching silica. As a result of the quaternary ammonium group in the anion exchange resin structure, these carbon spheres were doped with nitrogen. The performance of these carbon spheres in the catalytic dehydrochlorination of 1,2-dichloroethane (EDC) was improved with the increase of calcination temperature, and the carbon sphere 900-900-RC showed the highest conversion rate (96.7%) and a selectivity to vinyl chloride above 99%. The structural and surface properties of N-doped carbon spheres were characterized by scanning electron microscopy, nitrogen sorption, and Raman and X-ray photoelectron spectroscopy. The result of these characterizations further verified that the quaternary nitrogen species are as effective as pyridine nitrogen species in this catalyst.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zimo Lou,Jiang Xu,Jiasheng Zhou,Kunlun Yang,Zhen Cao,Yizhou Li,Yuanli Liu,Liping Lou,Xinhua Xu
Atomic H* has been regarded as the key active species for the electrocatalytic hydrodechlorination (ECH), and the electrode design and operation conditions are related to the atomic H* generation. However, there is limited understanding of how the operation parameters affect the atomic H* generation and utilization. Due to the fact that Pd was inefficient in water dissociation step, MnO 2 was combined with Pd to construct a novel Pd/MnO 2 /Ni foam cathode. Cyclic voltammetry confirmed that Pd/MnO 2 /Ni foam cathode with MnO 2 load of 0.51 mg cm −2 possessed the highest atomic H* generation and ECH activity. Excessive Pd load (>0.44 mg cm −2 ) was detrimental to ECH because of the side hydrogen evolution reaction (HER). Operation conditions (e.g. applied current and electrolyte concentration) would directly affect the cathode potential, which was an important indicator of the atomic H* generation. The optimal cathode potential was determined to be −0.85 V when the applied current was 10 mA in this study. The electrolyte concentration of 10–15 mM was able to provide sufficient atomic H* for ECH, while excessive input of electrolyte would favor HER but inhibit ECH. ECH at acidic and neutral/alkaline solution underwent different pathways for atomic H* generation and further affect the utilization of atomic H*. After 120 min reaction, >70% of atomic H* could be selectively used for ECH at initial pH of 4.0 and 5.0, while only ∼37% was used for ECH at initial pH of 7.0. This work correlated the reactivity of electrode with the atomic H* and cathode potential, which would provide strategies for ECH catalyst design and operation optimization.
研究领域:
环境科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Junjing Li,Han Yu,Yongjiao Ding,Liang Wang
In order to improve the metal utilization of the noble metal Pd and the catalytic activity of the reaction, a novel and efficient Pd/Ti 4 O 7 /Ti electrode was prepared by introducing a Ti 4 O 7 intermediate layer for electrocatalytic hydrodechlorination (EHDC) of chlorinated pharmaceuticals and personal care products (PPCPs). The presence of oxygen vacancies (Ov) on the Ti 4 O 7 surface was confirmed by electron paramagnetic resonance (EPR). The results showed that the introduction of Ti 4 O 7 increased the electrochemical active surface area electrode (ECSA) of the Pd/Ti 4 O 7 /Ti electrode, accelerated the electron transfer rate on the catalyst surface, and promoted the generation of electron-rich Pd, which in turn improved the dechlorination efficiency. The Pd/Ti 4 O 7 /Ti electrode had a removal efficiency of 99.6% for florfenicol (FLO) within 180 min. Meanwhile, the removal efficiency of the Pd/Ti 4 O 7 /Ti electrode was still above 95% in seven cycles, which significantly improved the catalytic activity and stability compared with that of the Pd/Ti electrode. In addition, the reaction pathway for the electrocatalytic hydrodechlorination process of FLO at Pd/Ti 4 O 7 /Ti electrode was proposed. The ecotoxicity of the pollutants was also evaluated by the Toxicity Estimation Software Tool (T.E.S.T) model. In this study, an efficient electrocatalyst for EHDC was explored, and the Pd/Ti 4 O 7 /Ti electrode provided strong support for pollutant removal.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Ge Song,Huizhong Wu,Xuechun Wang,Shuaishuai Li,Ruiheng Liang,Minghua Zhou
Electrocatalytic dechlorination by atomic hydrogen (H*) is efficient, but limited by the low efficiency of H* production. Herein, a phosphorus-doped cobalt nitrogen carbon catalyst (Co-NP/C) was prepared, which had high catalytic activity in a wide pH range (3−11). The turnover frequency of Co-NP/C (3.54 min −1 ) was 1.21–59000 times superior to that of current Pd-based and non-noble metal catalysts (0.00006–2.92 min −1 ). Co-NP/C significantly enhanced H* generation, which was 1.52, 2.44, and 3.77 times stronger than that of Co-N/C, NP/C, and N/C, respectively, since the introduction of phosphorus was found enhanced the electron density of cobalt and regulated the electron transfer . Co-NP/C showed outstanding catalytic performance after ten cycles and could achieve nearly complete chloramphenicol removal. This regulation method was verified to be effective for other non-noble metal (Fe, Mn, Cu, Ni) phosphorus doped catalysts, proposing a general class for efficient electrochemical dechlorination, which would be of great significance for the elimination of chlorinated organic pollutants .
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
FUEL
·
2023
·
IF 7.4
Hui Niu,Dengqian Zhang,Yaning Pei,Wei Zhang,Chen Zhang,Cuiqing Li,Long Huang
Catalytic dechlorination of model plastic pyrolytic oil was investigated over different types of zeolites and ion-exchanged 13X zeolites at the low temperatures of 20–120 °C. Among different types of parent zeolites (13X, β, MCM-41), 13X had the highest catalytic dechlorination performance. After ion exchange of 13X with Ag + , its catalytic dechlorination performance was significantly enhanced, and the chlorine removal over Ag-13X reached 97.2 % after reaction for 5 h at 120 °C. The characterization results indicated that the acidity of the zeolite governed its catalytic dechlorination performance, and higher acid amount and stronger acid strength are preferred. Different types of chlorinated compounds followed different dechlorination mechanisms. The primary chlorinated alkanes (e.g., 1-chlorooctane) underwent nucleophilic substitution by the surface –OH groups or H 2 O to form alcohols and HCl, or dehydrochlorination reaction to produce olefins and HCl, while higher chlorinated alkanes with adjacent hydrogen (e.g., chlorocyclohexane) mainly underwent dehydrochlorination reaction to produce olefins and HCl. Chlorinated aromatics (e.g., chlorobenzene) was removed mainly by physical adsorption. Ag-13X showed good stability, and the chlorine removal still retained 72.1 % after 102 h on stream. After four dechlorination-regeneration cycles, the chlorine removal had only a slight decrease due to the partial collapse of its structure and slight loss of its acid amount.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zheng Li,Jiehao Xie,Zipin Peng,Zhuo Ma,Yihui Li,Xingkun Chen,Yuan Tan,Wenshao Yang,Yunjie Ding
4-Chlorophenol (4-CP) is a pervasive environmental pollutant commonly found in wastewater and groundwater, posing great risks to both human health and the ecosystem. Catalytic hydrodechlorination (HDC) of 4-CP by utilizing hydrogen (H 2 ) as a reductant has emerged to be an efficient and sustainable way to treat pollutant water. This study focuses on the development of an efficient and stable Pd-based catalyst for the catalytic HDC of 4-CP. By incorporating an appropriate amount of Ni into Al 2 O 3 support, a NiAl 2 O 4 (NA) spinel was synthesized, enhancing the interaction between Pd and the support, leading to precise control over Pd species and oxygen vacancies. The tailored properties of the Pd/NA-1 catalyst result from meticulous adjustment of the Pd 2+ /Pd 0 ratio and oxygen vacancies, which promotes electron transfer from Pd to Ni within the NiAl 2 O 4 spinel. In comparison to the Pd/Al 2 O 3 catalyst, the Pd/NA-1 catalyst exhibits exceptional stability, with continuous operation for over 120 h without deactivation. Comprehensive characterization analyses indicate that the Pd/NA-1 catalyst effectively prevented the aggregation of Pd nanoparticles, maintaining the Pd 2+ /Pd 0 ratio at 1, which is crucial for its superior stability. This work provides valuable insights into the development of Pd-based catalysts for HDC reactions, highlighting the potential use of Pd/NA-1 catalysts in treating hazardous pollutants like 4-CP in waste systems.
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
·
2018
·
IF 11.698
Jiasheng Zhou,Zimo Lou,Kunlun Yang,Jiang Xu,Yizhou Li,Yuanli Liu,Shams Ali Baig,Xinhua Xu
In the present study, carbon black (CB), multi walled carbon nanotubes (MWCNTs), and granular activated carbon (GAC) were employed to support palladium (Pd) catalyst. The prepared Pd/CB, Pd/MWCNTs and Pd/GAC moveable catalysts were aimed to address the common issues (easy loss of catalyst and poor long-term performance) of normal fixed catalysts. The results of various characterizations (e.g., TEM, XRD, and XPS) clearly show that the Pd nanoparticles were successfully loaded onto the carbon-supports, especially CB and MWCNTs. And more importantly, the morphologies, Pd distribution, and chemical structure of these moveable catalysts were almost not changed after 3 h reaction. The moveable Pd/CB, Pd/MWCNTs, and Pd/GAC catalysts had good reactivity for 2,4-dichlorobenzoic acid (2,4-DCBA) dechlorination, and Pd/CB exhibited the best performance. The Pd/CB also shows the best adsorption capacity of 2,4-DCBA and dechlorination product (benzoic acid, BA), and the adsorption of BA was significantly inhibited in the presence of current due to the repulsion between the both negatively charged compounds and adsorbents. The removal of 2,4-DCBA and the generation rate of BA was improved with a pre-adsorption process, which was a promising strategy with higher dechlorination rate and shortened electrolysis time. Moreover, the loss of Pd catalyst was negligible during the 10 consecutive cycles experiment, and the improved longevity could be expected. These results suggested the good reactivity, stability, and reusability of moveable Pd/CB catalyst.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 8
·1827-1835
·
IF 5.2
Zipin Peng,Xuepeng Wang,Zheng Li,Xingkun Chen,Yunjie Ding,Jisong Zhang
Catalytic hydrodechlorination (HDC) is considered to be a safe and effective method to treat chlorinated organic pollutants and has always been a hot spot in basic catalysis research. It is difficult to obtain excellent catalytic performance due to the inferior mass transfer performances of traditional batch reactors, and the deactivation of catalysts can easily occur due to the poisoning effect of HCl. In this work, Pd catalysts supported on activated carbon (Pd/AC) were synthesized by the ion-exchange (IE) method. The characterization results of N2 physisorption, XRD, TEM and XPS revealed that the active Pd components were uniformly dispersed on the surface of AC in the form of nanoparticles. A continuous flow system based on a micro-packed bed reactor (μPBR) was developed for the hydrodechlorination, and the hydrogenation of chlorobenzene (CB) was selected as the model reaction. With the optimal reaction conditions, a conversion and selectivity of 100% were obtained. Importantly, no obvious deactivation of the catalysts was observed during a 100 h time-on-stream test. Moreover, Pd/AC catalysts exhibited remarkable substrate suitability in dechlorination systems. The reaction kinetics for hydrodechlorination of CB in methanol was investigated after the internal and external diffusion limitations were eliminated.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Jianhui Xu,Xin Fu,Yufeng Liu,Yunfei Zhang,Shenggui Chen,Dan Li,Chunhui Zhang,Jiale Gao,Yibo Fu
Electrocatalytic hydrodechlorination technology provides an attractive strategy to effectively eliminate the biotoxicity of halogenated organic pollutants (HOPs). Herein, we demonstrated a highly dispersed Pd loaded on blue TiO 2 nanotube arrays (Pd x -BTNA) cathode that can achieve efficient dechlorination and detoxification toward florfenicol (FLO). Characterization results indicated that strong interaction between Pd and BTNA was achieved through Pd-O bonds, which facilitated the electron transfer rate. Pd x -BTNA significantly outperformed other cathodes (i.e., BTNA, Pd x -TNA and Pd x -Ti) in the electrocatalytic dechlorination of FLO due to enhanced utilization of active H*. The dechlorination performances of FLO well followed the pseudo-first-order kinetic, and the reaction constant rate on Pd x -BTNA cathode (0.035 min −1 ) was 17.5, 1.94, 7.0 times higher than that on BTNA, Pd x -TNA and Pd x -Ti cathodes, respectively. Quenching experiments and electrochemical characterization indicated that both direct electron transfer and indirect reduction process mediated by H* were involved in the dechlorination of FLO. The optimal dechlorination efficiency of 98.79% was obtained by Pd x -BTNA cathode within 120 min at 1 mM PdCl 2 , applied cathode potential of −1.2 V. In addition, Pd x -BTNA exhibited superior stability and durability with almost no Pd leaching (0.0011 mg/L) during five dechlorination cycles. Our research proposed a novel strategy to design low noble Pd-loaded cathode material for efficient dechlorination and detoxification of HOPs.
研究领域:
环境科学
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Xin Ning,Yuhan Sun,Heyun Fu,Xiaolei Qu,Zhaoyi Xu,Shourong Zheng
Metal-organic frameworks (MOFs) have received significant attention as promising precursors or sacrificial templates in the preparation of porous carbon supported catalysts. In this study, N-doped porous carbon supported Ni catalysts (denoted as Ni/NC) were prepared using furfuryl alcohol (FA) loaded Ni-MOF-74 as the precursor followed by NH 4 OH treatment and pyrolysis under N 2 atmosphere. For comparison purpose, Ni catalysts supported on porous carbon (denoted as Ni/C) were also prepared by direct pyrolysis of Ni-MOF-74. The selective gas phase catalytic hydrodechlorination of 1,2-dichloroethane to ethylene was carried out to evaluate the catalytic performances of the catalysts. It was found that for Ni catalysts prepared at the same pyrolysis temperature, Ni particle sizes in Ni/NC catalysts were significantly smaller (20–40% smaller) than that of Ni/C. This reflected that pre-modification of Ni-MOF-74 using FA and NH 4 OH could effectively increase Ni dispersion in Ni catalysts derived from Ni-MOF-74. Moreover, Ni/NC had a markedly stronger ability to form spillover H 2 owing to the enhanced metal-support interactions by N-doping. Accordingly, Ni/NC catalysts exhibited much higher catalytic activities than Ni/C catalysts. The turnover frequencies of Ni/NC catalysts were found to be 1.22–1.65 times higher than Ni/C catalysts. Increasing pyrolysis temperature led to decreased catalytic activities of both Ni/C and Ni/NC catalysts, due to the aggregation of Ni particles at higher treatment temperature. The findings from this study demonstrate that the MOF-mediated synthesis method offers a promising way to prepare Ni-based catalysts for catalytic hydrodechlorination of chlorinated hydrocarbons .
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）