Processes
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2022
·Vol. 10
·期 4
·751
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IF 3.352
Zixuan Tang,Zehui Bai,Xin Li,Le Ding,Bin Zhang,Xinghua Chang
Cu-based bimetallic materials have been widely reported as efficient catalysts for electrocatalytic nitrate reduction. However, the faradaic efficiency and selectivity are still far from satisfactory. Herein, Cu-Fe bimetallic nanoalloys with adjustable Cu/Fe ratios are successfully prepared through a reactive mechanical milling approach with CuCl2, FeCl3and Na as the starting materials. The optimized Cu3Fe exhibits excellent nitrate conversion efficiency of 81.1% and 70.3% ammonia selectivity at −0.7 V vs. RHE within 6 h under 0.1 M Na2SO4and 100 ppm NO3−. The Fe-introduction-induced upshift of thed-band center is identified to be beneficial for promoting nitrate adsorption on Cu3Fe. Moreover, favorable H generation under the assistance of Fe could effectively accelerate the stepwise hydrogenation during electrocatalytic nitrate reduction, resulting in significantly improved NH4+selectivity. This work supplies valuable insights for the rational design of transition-metal-based bimetallic catalysts for electrocatalytic nitrate reduction.Keywords:Cu-Fe bimetallic catalysts;nitrate to ammonia;d-band center regulation
研究领域:
电化学催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Dandan Zhu,Meijuan Chen,Yu Huang,Rong Li,Tingting Huang,Jun-ji Cao,Zhenxing Shen,Shun Cheng Lee
Formaldehyde is a typical indoor air pollutant that has posed severely adverse effects on human health. Herein, a novel FeCo alloy nanoparticle-embedded nitrogen-doped carbon (FeCo@NC) was synthesized with the aim of tailoring the transition-metal d-band structure toward an improved formaldehyde oxidation activity for the first time. A unique core@shell metal–organic frameworks (MOFs) architecture with a Fe-based Prussian blue analogue core and Co-containing zeolite imidazole framework shell was firstly fabricated. Then, Fe and Co ion alloying was readily achieved owing to the inherent MOF porosity and interionic nonequilibrium diffusion occurring during pyrolysis . High-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectra confirm that small FeCo alloys in situ form in FeCo@NC, which exhibits a higher formaldehyde removal efficiency (93%) than the monometallic Fe-based catalyst and a remarkable CO 2 selectivity (85%) at room temperature. Density functional theory calculations indicate the number of electrons transferred from the metal core to the outer carbon layer is altered by alloying Fe and Co. More importantly, a downshift in the d-band center relative to the Fermi level occurs from − 0.93 to − 1.04 eV after introducing Co, which could alleviate the adsorption of reaction intermediates and greatly improve the catalytic performance.
研究领域:
环境科学
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材料科学
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化学
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 13
·3975-3983
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IF 6.1
Huiqin Yu,Fang Li,Jing Cao,Shifu Chen,Haili Lin
Developing highly active and stable bifunctional electrocatalysts for the oxidation of alcohols is critical for energy and chemical conversion. Herein, a NiCo2O4 nanowire on ultrathin porous carbon (NiCo2O4/C) was fabricated and exhibits superior electrocatalytic performance for both hydrogen evolution and benzyl alcohol (BA) oxidation in comparison with pristine NiCo2O4 free of carbon. It only needed 1.36 V vs. RHE to afford a current density of 50 mA cm−2 for BA oxidation. The overpotential for the HER (η10) is −93.0 mV vs. RHE. Furthermore, high yield (96.0%) and faradaic efficiency (98.6%) of benzoic acid were achieved in 10 consecutive stability tests. The outstanding electrocatalytic activity can be attributed to the following aspects: (1) the hierarchical architecture exposed more catalytic active sites and enhanced mass transport; (2) ultrathin porous carbon strengthened the affinity for the reaction medium; (3) strong electronic interactions optimized the energy band structure. DFT simulations proved that the Gibbs free energy of the rate-determining step was reduced when coupling with ultrathin porous carbon, thus lowering the energy barrier and accelerating the reaction process. Theoretical calculations further reveal that the moderate downshift in the Ed energy levels, which balance the adsorption and desorption of the intermediates, is the intrinsic reason for the promoted oxidation activity. This work could provide valuable insights into the design of highly efficient bifunctional electrocatalysts.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Sixia Liu,Xiaobo Zhang,Nidu Wang,Nagimovich Karimov,Yujie Wang,Zihan Gao,Dongguang Wang,Baikang Zhu,Shuying Gao,Fu Yang
The electrochemical nitrogen reduction reaction (e-NRR) is a promising energy-efficient and low-emission alternative to the traditional Haber–Bosch process, but the sluggish kinetic and difficult activation of nitrogen impede the reaction activity. In particular, addressing the weak interaction of nitrogen with catalysts is very challenging in this field. Here, a surface oxygen vacancies tailored method was proposed to shift the d -band center of iron-based electrocatalysts to Femi energy level, by leveraging molecule self-assembly strategy to obtain Fe-base gels followed by ultrafast calcined process. The optimal electrocatalysts (Fe 3 O 4 -xGO) possess a hierarchical porous architecture (coral-like morphology), thereby endowed with outstanding structural properties (329.1 cm 2 g⁻ 1 ). Meanwhile, interfacial oxygen vacancies could be constructed during the ultrafast heat-pyrolysis process, and their concentration could be tailored with the assistance of graphene oxide (GO). Benefiting from these structure characters, the d -band center of Fe in coral-like iron oxide can be shifted to a higher energy level, which is conducive to trapping and activating the intermediate in the e-NRR process. The results of the electrocatalytic NRR test, as anticipated, indicated that Fe 3 O 4 –10GO achieved a high Faradaic efficiency of 28 % and an NH 3 production rate of 30.45 μg h⁻¹ mg cat ⁻¹ at −0.3 V vs. RHE in a 0.1 M Na 2 SO 4 , positioning it comparably to most iron-based electrocatalytic materials used in e-NRR applications. This work could provide new insight for moldering the d band center of the electrocatalyst.
研究领域:
材料科学
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电催化
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yuanchuan Ren,Yan Hu,Nanqi Ren,Xiaojuan Su,Fenghui Wu,Dandan Chen,Xuejun Zhu,Qiang Niu,Yan Guo
Persulfate (PMS) is an excellent free radical initiator with selective degradation of organic pollutants. This article presents the preparation of a high-performance Cu-SA@NCA(Single atom copper modified nitrogen doped aerogel carbon) electrocatalyst with adjustable interfacial separation enhancement effect for the first time. Under the optimal process parameters, the removal rates of ENO, COD, and TOC obtained after 5 min of reaction were 100 %, 73.41 % and 55.15 %, respectively. The average energy consumption was saved by 59.63∼123.25 kWh/kg ENO. After 6 cycles of degrading ENO wastewater, the removal rate of ENO only decreased by 8.55 %. It was demonstrated through characterization such as high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), X-ray absorption near edge structure (XANES), and Fourier Transform Extended X-ray Absorption Fine Spectroscopy (FT-EXAFS) that the single atom copper loaded on the Cu-SA@NCA surface is tightly bound to N in NCA through Cu-N 4 bond bridges, promoting the formation of double electron centers on the catalyst surface. The particle electrode catalyst significantly enhances the PMS activation process over a wide pH range and can accelerate the degradation of enoxacin (ENO). As the reaction center for PMS adsorption and activation, Cu-N 4 has a lower charge transfer resistance and can attract PMS to the catalyst surface, resulting in a higher current response in the PMS system. Organic pollutants release electrons through the carbon matrix of carbon based catalysts and transfer them to Cu-SA@NCA-PMS, promoting PMS activation and the formation of high valence copper ions, enhancing the degradation of pollutants. Density functional theory (DFT) further indicate that the regulatory effect of N on the electron distribution of Cu d orbitals is beneficial for the stretching and cleavage of Cu active centers by PMS, accelerating the process of SO 4 − · and ·OH generation rate, which is consistent with the results of XANES. In addition, during the degradation process of salt containing organic pollutants in PMS, Cu-SA@NCA exhibits strong resistance to inorganic ions, natural organic matter, and pH value. This work developed a new catalyst that selectively produces SO 4 − · and ·OH with 97.46 % selectivity, achieving high selectivity and efficiency in degrading pollutants.
研究领域:
环境科学
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电化学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
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2025
·
IF 14.9
Lina Hu,Zengyu Han,Ya Chen,Yaoda Liu,Lei Li,Jie Su,Zhengfei Dai,Dong-Shuang Wu
The development of pH‐robust electrocatalysts is highly desirable but challenging for the hydrogen evolution reaction (HER) in water electrolysis. Among the noble metal groups, ruthenium (Ru) holds the promise in balancing the cost and activity in HER, but it is restricted by the strong H adsorption and the sluggish Heyrovsky step. It appeals for a rational d -band manipulation to neutralize the hydrogen adsorption to promote the HER kinetics. Herein, we profiled a confined structure with RuCo alloy nanoparticles in N-doped carbon nanofiber (RuCo@NCNF) by a facile electrospinning-pyrolysis process for HER electrocatalysis. An electron transfer from Co to Ru is indicated in the RuCo@NCNF composite to enhance the electron-donating character of Ru active sites to couple the HER. Resultantly, the optimized Ru 1 Co 2.5 @NCNF catalyst stably exhibits the Pt-beyond HER activity in both alkaline (10 mV at 10 mA cm −2 ) and acidic electrolytes (23 mV at 10 mA cm −2 ), while delivering competitive HER performance in neutral electrolytes. Density functional theory (DFT) calculations also confirm that the Ru-Co electronic interactions can effectuate the d -band center downshift, moderating the adsorption energies of hydrogen (Δ G H* ) and H 2 O for efficient hydrogen production. This study provides a reference for the rational design of Ru-based pH-robust HER electrocatalyst through confined nanoalloy structures.
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy Materials
·
2024
·Vol. 14
·期 36
·2401509
·
IF 24.4
Han Yu,Guoliang Zhang,Dongmei Zhang,Ruonan Yang,Xia Li,Xiuqi Zhang,Gang Lian,Hua Hou,Zhanhu Guo,Chuanxin Hou,Xiaoyang Yang,Feng Dang
Although lithium–oxygen batteries (LOBs) hold great promise as future energy storage systems, they are impeded by insulated discharge product Li 2 O 2 and sluggish oxygen reduction reaction/oxygen evolution revolution (ORR/OER) kinetics. The application of a highly efficient cathode catalyst determines the LOBs performance. The d-band modulation and catalytic kinetics promotion are important concept guidelines for the performance enhancement of cathode catalysts. In this work, the homogeneous in-plane distortion-derived synergistic catalytic capability of an Ag 2 Mo 2 O 7 catalyst with modulated d-band centers and promoted ORR/OER kinetics is demontrated. The uniform elongation of Ag─O bonds and compression of Mo─O bonds in (020) plane leads to d-band splitting and d-band center optimization and delivers improved adsorption behavior for high ORR/OER capability. Furthermore, the spatial and energy overlap of Ag d xz and O 2 anti-bonding π * orbitals facilitate electron injection during ORR process and reduce the energy barrier for charge transfer and O 2 desorption during OER process, accelerating the ORR/OER kinetics. As a result, the (020) plane-exposed Ag 2 Mo 2 O 7 cathode exhibits ultralong cycle stability of 817 cycles at 500 mA g −1 and large specific discharge/charge capacities of 15898/15180 mAh g −1 . This work provides facile concept guidance for optimizing catalytic capability through controlled lattice distortion in cathode catalysts for LOBs.
研究领域:
材料科学
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电化学
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能量存储
·
催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）