CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Xinyuan Zhou,Qiyan Sun,Xinlin Wang,Ruixue Zhang,Bin Li,Zexing Wu,Dehong Chen,Lei Wang,Guang-Rui Xu
Synthesis of cost-effective electrocatalysts for oxygen reduction reaction (ORR) has received wide attention due to their sluggish kinetics, which limits the development and application of fuel cell technique. In this work, we report a versatile synthetic approach to prepare a series of small-sized Ag@MNi (M = Pd, Pt, Rh, Ru) nanocrystals with core–shell structures by a simple solvothermal method. According to characterization analysis, surface segregation of Pd was proved in the outermost layer with the Pd-rich shell layer, which can regulate the adsorption energy of *OH. Electrochemical results show that the onset potential and half-wave potential of Ag@PdNi nanocrystals (Ag@PdNi NCs) are 1.005 and 0.913 V vs. RHE (reversible hydrogen electrode), respectively, with a Tafel slope of 55.31 mV dec -1 and strong ORR catalytic durability, which is similar to Ag@MNi (M = Pt, Rh, Ru) NCs and slightly higher than that of PdAg alloy nanoparticles (PdAg alloy NPs), PdNi alloy nanoparticles (PdNi alloy NPs), commercial Pd black and even commercial Pt/C, in alkaline medium. Density Functional (DFT) calculations show that the presence of Ag core effectively promotes the segregation of Pd atoms to the outer shell surface, where Ni provides better segregated substitution sites for Pd, which significantly improves the ORR activity and durability due to the electronic synergistic effect between Ag core nuclei and Pd shell can reduce the adsorption strength of OH ads .
研究领域:
材料科学
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电化学
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催化科学
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产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Fengyang Liu,Wenjie Zou,Wei Zhao
Chitosan-based flocculants represent a highly promising alternative to industrial synthetic organic flocculants, offering exceptional environmental friendliness and efficiency. The carboxymethyl chitosan- graft -poly (acrylamide-dimethyl diallyl ammonium chloride) (CMCPD) and chitosan- graft -poly (acrylamide-dimethyl diallyl ammonium chloride) (CPD) were successful synthesized using UV-induced graft polymerization. The flocculation behavior and mechanism of these two chitosan-graft-copolymers on kaolinite suspension were investigated employing settling test and density functional theory calculation of the structural units of CMCPD and CPD on the kaolinite (00–1) surface. Experimental results indicated that the CMCPD had a greater settling rate of 19.47 m/h at the dosage of 80 g/t than CPD (12.96 m/h). The simulation results revealed distinct adsorption conformations of CMCPD and CPD units on the kaolinite (00–1) surface, characterized by an inclined posture and a horizontal posture, respectively. The stable adsorption of CPD can be attributed to the electrostatic attraction, which is evidenced by its higher adsorption energy (−4.74 eV) on the kaolinite (00–1) surface compared to CMCPD (−3.63 eV). It should be noted that both the adsorption energy and conformation play crucial roles in determining the flocculation efficiency of a flocculant. The inclined adsorption of CMCPD not only displayed electrostatic attraction but also enhanced its bridging ability, leading to a rapid increase in floc size and settling rate. The settling performance was significantly influenced by the bridging effect exerted by flocculants. This study holds great significance for the advancement of novel and efficient flocculant development.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Nano Energy
·
2019
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IF 15.548
Biwei Wang,Jinxiang Zou,Xiaochen Shen,Yuchi Yang,Guangzhi Hu,Wei Li,Zhenmeng Peng,Dustin Banham,Angang Dong,Dongyuan Zhao
Iron-nitrogen-carbon (Fe-N-C) materials featuring Fe-N 4 moieties are promising candidates to replace commercial Pt/C catalysts for the oxygen reduction reaction (ORR). Here we report a novel Mn-Fe-N/S@mC catalyst comprising atomically dispersed Fe-N 4 sites and a trace amount of Mn-N 2 S 2 sites, which are homogeneously anchored on an ordered mesoporous graphitic carbon framework. This dual-metal catalyst is realized based on the chemical conversion of self-assembled Mn 0.43 Fe 2.57 O 4 nanocrystal supracrystals, with the dual metal sites and the graphitic framework derived from nanocrystal cores and the associated capping ligands, respectively. When evaluated as electrocatalysts for the ORR, Mn-Fe-N/S@mC exhibits excellent catalytic activity in alkaline media , outperforming conventional Pt/C and most non-precious-metal catalysts reported previously. Notably, the synergistic effect of having Fe and Mn together improves the catalytic activity by a factor of ~ 5. To better understand the high efficiency of Mn doping in enhancing the activity of Fe-N 4 sites, density functional theory calculations were carried out, revealing that the synergistic interaction between the dual metal sites reduces the *OH reduction energy barrier during the oxygen reduction pathway.
研究领域:
催化化学
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材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
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2020
·Vol. 34
·期 8
·e5722
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IF 3.14
Jiadong Wang,Fakhre Alam,Qiqi Chang,Yanhui Chen,Tao Jiang
The methylene spacers and an uncoordinated diphenylphosphine moiety in the scaffold of the CH 3 Si(CH 2 ) n (PPh 2 ) 3 and Si(CH 2 PPh 2 ) 4 -type silylated diphosphine Ni(II) complex systems have a marked impact on their catalytic performance in selective ethylene dimerization. Ni(II)-based precatalyst 1 , bearing two methylene spacers in its framework, exhibited the highest catalytic activity of 1.29 × 10 8 g (mol Ni ) -1 h -1 , while precatalyst 3 , with three methylene spacers, affords the highest product selectivity (88%) toward the C 4 fraction. Crystallographic investigations revealed that the precatalyst 3 adopts the mononuclear bidentate binding mode and the steric constraints of its uncoordinated diphenylphosphine moiety may successfully tailor the catalytic environment of the catalyst. The precatalyst 4 may form a dinuclear complex and exhibits high catalytic activity by changing the ligand/Ni molar ratio. The high C 4 selectivity of precatalyst 3 has been rationalized by density functional theory (DFT) calculations and found to be consistent with the experimental results. The study also revealed that designing new systems of Ni(II)-based complexes and their systematic modifications may further provide potential and industrially viable catalyst systems for selective ethylene oligomerization.
研究领域:
化学
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催化材料
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理论计算
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2018
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IF 6.653
Ming Lei,Shun Guo,Zhiying Wang,Lihua Zhu,Heqing Tang
Fast and deep debromination of polybrominated diphenyl ethers (PBDEs) under mild conditions is a challenge in the field of pollution control. A strategy was developed to achieve it by exploiting Cu/TiO2 composites as a noble-metal-free catalyst. Toward the debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) as a typical PBDE, the use of Cu/TiO2 as a catalyst and hydrazine hydrate (N2H4·H2O) as a reducing agent yielded a degradation removal of 100% and a debromination efficiency of 87.7% in 3 s. A complete debromination of BDE47 at 1500 mg L–1 was possible by successively adding N2H4·H2O. A debromination pathway involving active H atom species was proposed for the catalytic transfer hydrogenation (CTH) of PBDEs according to the identified degradation intermediates. A mechanism was further clarified by density functional theory calculations: electrons are delivered from N2H4·H2O to the metallic Cu atom via a coordination of N in N2H4·H2O with Cu atoms. The electron-trapped Cu atom interacts with adsorbed BDE47 to form a transition complex, and then the debromination of this complex occurs on the surface of Cu nanoparticles due to the hydrogen donation of N2H4·H2O through the CTH process. The new method provides a highly efficient method to remove brominated pollutants.
研究领域:
环境科学
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污染控制化学
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材料科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2025
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IF 7.2
Yinlin Chang,Tao Liu,Jingyuan Rao,Min Fu,Yijun Guo,Shuliang Zou,Dewen Tang,Zetian Tao
The safe immobilization of radiotoxic strontium (Sr) in high-level radioactive waste (HLW) remains a major challenge due to its tendency to segregate and leach under aqueous conditions. In this study, a surface vanadium (V) engineering strategy is proposed to enhance the chemical stability of Sr 2 Fe 1.5 Mo 0.5 O 6-δ (SFM) ceramics. V-doped samples (SFMV), synthesized via a sol-gel method with 0.05 mol V partially substituting Mo, show improved resistance to Sr migration. DFT calculations reveal that V modification increases the Sr migration barrier from 0.14 eV (in SFM) to 0.34 eV (in SFMV) and induces the formation of strong Fe-O-V, and Mo–O–V effectively suppressing Sr surface segregation. Additionally, the formation of SrMoO 4 phases may act as Sr sinks, further enhancing stability. Leaching tests show that the Sr release from SFMV drops from 7.43 × 10 −4 to 2.89 × 10 −6 g·cm −2 ·d −1 over 42 days, representing a 64 % reduction compared to pristine SFM. This work provides a promising strategy for designing durable ceramic hosts for Sr-containing HLW.
研究领域:
材料科学
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核工程
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环境化学
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固态化学
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
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2024
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IF 4.4
Xinxin Fu,Dongling Cai,Yingying Zhang,Fangdong Ning,Xianmei Ma,Ying Luo,Wei Li,Lei Zou,Yongjun Zhang
Polycondensations play a significant role in the synthesis of polymer materials. However, most traditional polycondensation reactions suffer from slow reaction rates, low efficiency, non-negligible reaction equilibrium and side reactions, low atom economy, and stringent conditions. Previously, we have found the unique regioselective Friedel–Crafts hydroxyalkylation polycondensation between 1,4-disubstituted benzenes and 4-substituted benzaldehydes to produce high molar mass polymers with triarylmethane backbone structures. In this study, we first found the regioselective Friedel–Crafts hydroxyalkylation type small molecule model reaction between 4-methylanisole and 4-nitrobenzaldehyde. By density functional theory calculations, we elucidated the mechanism of this model reaction to quantitatively give a single product with the structure that two 4-methylanisoles were linked together by one 4-nitrobenyl group at the ortho position of the methoxy group. Finally, we show that this model reaction can be successfully developed as a versatile, facile, mild, nonstoichiometric, highly efficient, and atomic economic polycondensation reaction that can produce linear polymers with different backbone structures. This type of Friedel–Crafts hydroxyalkylation polycondensation enriches the collection of polycondensation reactions and is of great significance for overcoming the drawbacks of traditional polycondensation reactions.
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
Nanoscale
·
2025
·Vol. 17
·期 5
·2820-2829
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IF 5.1
Yiling Ran,Rong Gan,Qin Zhao,Quanlei Ma,Yijing Liao,Yinwei Li,Yi Wang,Yanwei Wang,Yan Zhang
Engineering the local electronic structure of single atom catalysts (SACs) still remains challenging. In this study, a Ru-NiS2 single atom catalyst with a controlled S coordination environment, where Ru single atoms are implanted on a NiS2 nanoflower consisting of plenty of cross-linked nanosheets, has been developed via a facile atom capture strategy. Using Density Functional Theory (DFT) calculations, it has been revealed that the fine-tuned local S coordination environment can optimize the electronic structure of Ru active sites, and reduce the energy barrier of the rate-determining step for the oxygen evolution reaction (OER), thus boosting the electrocatalytic activity, such as a low overpotential of 269 mV at 10 mA cm−2. This work provides new insights into the rational regulation of the local coordination environment for SACs.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2021
·
IF 4.759
Junnan Li,Yaming Sun,Longhui Liu,Hailiang Zhao,Wenjie Zhao,Lijun He,Shusheng Zhang
A 34-membered tetraazahexaphenylmacrocycle (N 4 Ph 6 ) with a rigid π-conjugated moiety was chemically bonded to silica gel with 3-chloropropyltrimethoxysilane as the coupling agent to prepare a novel SiO 2 @N 4 Ph 6 stationary phase. Several common organic analytes, including alkylbenzenes , polycyclic aromatic hydrocarbons , anilines, phenols, phthalates , and folic acid , were selected as probes to investigate its chromatographic performance. The as-developed SiO 2 @N 4 Ph 6 stationary phase showed superiority retention and high selectivity for probe molecules through multiple interactions, including hydrophobic, π–π, hydrogen-bonding, and steric interactions. Density functional theory calculation results using folic acid as model solute provided an intuitive and a quantitative description of the multiple retention mechanisms.
研究领域:
分析化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemCatChem
·
2019
·Vol. 11
·期 11
·2676-2682
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IF 4.495
Qinglin Yuan,Wanbing Gong,Yixing Ye,Jun Liu,Yue Lin,Chun Chen,Haimin Zhang,Pengfei Li,Weiren Cheng,Xiangjun Wei,Changhao Liang
Graphical Coupling reaction : A novel Pd/BiOCl catalyst is designed to catalyze benzaldehyde for high-selectively synthesizing benzoin ethyl ether utilizing the nucleophilic action of Cl − ions. DFT calculations and experimental evidences demonstrated the key role of dissociated Cl − ions with Pd NPs by suppressing the dissociation of Cl − ions and changing the reaction pathway. Exploring novel catalyst supports with unique performance creates more opportunity for transforming organic chemicals in heterogeneous catalysis. In this paper, BiOCl is first presented as an effective support for Pd nanoparticles (NPs) toward application in the coupling reaction of benzaldehyde. The Cl − ion dissociates from BiOCl, which forms nucleophile with Pd nanoparticles; this is key for the one-step synthesis of benzoin ethyl ether, the conversion and selectivity of which can reach to 100 % and 97.9 % at 100 °C, respectively. DFT calculations reveal that Cl − ions can be stabilized by stronger Bi−Cl bonds through doping of Fe ions in substituting Bi sites in BiOCl. The parallel catalytic evaluation using Pd/Fe-doped BiOCl catalyst shows the suppression of coupling reaction, conversely, demonstrating the crucial role of nucleophile. This work provides new insights into support tailoring for the synthesis of vital organic chemicals in heterogeneous catalysis by changing chemical reaction pathway.
研究领域:
催化化学
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材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
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2022
·
IF 16.383
Kang Ma,Tiantong Zhang,Ying Qin,Zhixin Hu,Zhixiang Sun,You Han,Dongbing Zhao,Hong-Ying Gao
Desilylative coupling involving C–Si bond cleavage has emerged as one of the most important synthetic strategies for carbon–carbon/heteroatom bond formation in solution chemistry. However, in on-surface chemistry, C–Si bond cleavage remains a synthetic challenge. Here, we report the implementation of C(sp2)–Si bond cleavage and subsequent C–C bond formation on metal surfaces. The combination of scanning tunneling microscopy and density functional theory calculation successfully reveals that the incorporation of the C–Br group on the arylsilanes is critical to the success of this desilylative coupling reaction on metal surfaces. Our study represents a promising approach for the removal of protecting silyl groups in on-surface chemistry.
研究领域:
表面科学
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材料化学
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理论化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yuelong Liu,Mengshan Chen,Xue Zhao,Haoran Zhang,Yan Zhao,Yingtang Zhou
Electrochemical-nitrate-reduction-reaction (eNitRR) ammonia synthesis shows the vision of green ammonia synthesis and is also an effective way to purify nitrate wastewater. In this study, the complex of 1,10-phenanthroline and Cu 2+ was adsorbed on the surface of polydopamine-derived nitrogen-doped-hollow-carbon-spheres, and sub-nanometer-scale copper species (CuCN/NHCSs) were obtained after heat treatment. Using CuCN/NHCSs as catalyst, the ammonia yield rate and Faradaic efficiency of eNitRR reached 21413.5 μg h −1 mg cat. −1 (−1.1 V vs RHE) and 91.08% (−0.9 V vs RHE), respectively. CuCN/NHCSs still have high catalytic activity for eNitRR even in complex water environments (such as acidity, alkalinity, coexisting ions). In the face of low concentration of nitrate in natural sewage, CuCN/NHCSs as a catalyst can reduce the concentration of NO 3 − to below the limits set by WHO and US EPA within 10 h, and achieve effective purification of nitrate sewage. DFT calculations show that both single-atom Cu sites and Cu atom cluster sites on NHCSs can promote the electrochemical conversion of NO 3 − to ammonia, so minimizing copper sites can maximize the unit activity. Furthermore, the simultaneous anchoring of Cu atom clusters and single-atom Cu in the carbon matrix is beneficial to lower the energy barrier of the potential-determining step of eNitRR.
研究领域:
环境科学
·
电化学
·
材料科学
✓ 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）