INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
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IF 8.1
Yu Tan,Yike Wei,Gaigai Liu,Yuhang Cai,Siyu Liu,Shijie Wang,Shenghan Zhang,Kexin Liang
The mild reaction conditions, simple process, and clean raw materials make electrochemical nitrogen reduction reaction to ammonia (NRR) a promising method for producing this crucial substance for human life. The proposed catalysts have been shown to reduce the reaction barrier and improve catalytic efficiency, making them an excellent choice for this process. Carbon nanotubes coated FeMoO 4 (FeMoO 4 @CNTs) nanorods are a highly efficient catalyst for fixing N 2 to NH 3 . Carbon nanotubes doped FeMoO 4 improve the efficiency of electrocatalytic NRR by increasing their active surface. A superior ammonia yield of 18.49 μg h −1 ·mg·cat −1 at −0.65 V was obtained in a 0.1 mol L −1 Na 2 SO 4 solution, with a corresponding Faraday efficiency of 16.14%. The response of the experimental system to environmental factors was also investigated. The data clearly indicates that raising the temperature does not enhance the yield of ammonia. This reaction system is optimal for neutral or alkaline environments.
研究领域:
化学
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材料科学
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环境科学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
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IF 3.9
Cuilian Sun,Huhu Yin,Xiujing Xing,Yaokang Lv,Wei Xiong,Hao Li
In recent years, a variety of catalysts have been applied to electrocatalytic nitrogen reduction (NRR). Previous research has shown that in bimetallic catalysis the synergistic effect between the bimetals results in catalytic properties superior to those of monometallic catalysts. In this work, bimetallic oxide MnMoO4 nanomaterials with different particle sizes were prepared by a solvothermal method, and the effects of different ratios of the solvents (water/ethylene glycol) on the particle sizes of MnMoO4 and their influence on the NRR performance were systematically investigated. The results showed that as the proportion of ethylene glycol solvent increased, scanning electron microscopy (SEM) characterization showed a transformation of morphology from micrometer-scale rods to nanoscale particles, and the smallest MnMoO4 particle size was obtained at a water/ethylene glycol ratio of 0:1. Under this condition, the formed MnMoO4 exhibited excellent NRR properties at −0.40 V vs RHE with an NH3 yield as high as 21.89 μg h–1 mgcat–1 and a Faraday efficiency (FE) of 15.12%, with the best stability among all catalysts synthesized in this work. This may be attributed to the increased viscosity of the ethylene glycol environment, leading to a deceleration of the precursor reactions. This leads to the production of materials with smaller particle sizes, exposing more active sites and improving catalytic performance. In addition, we explored the effect of other solvents (n-butanol and glycerol) on the morphology of the materials. This work indicates that changing the solvent to regulate the morphology and size of the bimetallic oxide MnMoO4 can improve the catalytic efficiency of the catalyst, providing a promising electrocatalyst for nitrogen reduction reactions.
研究领域:
材料科学
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催化化学
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能源化学
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 45
·16670-16679
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IF 4
Huhu Yin,Xiujing Xing,Wei Zhang,Jin Li,Wei Xiong,Hao Li
Electrocatalytic nitrogen reduction (NRR) for artificial ammonia synthesis under ambient conditions is considered a promising alternative to the traditional Haber–Bosch process. However, it still faces multiple challenges such as the difficulty of N2 adsorption and activation and limited Faraday efficiency. In this work, a bimetallic oxide MnMoO4 was prepared by a hydrothermal method and low temperature calcination. The influence of the sintering temperature on the microstructure (crystallinity and oxygen vacancies) of the oxide and its NRR properties were systematically explored. The results showed that MnMoO4 sintered at 500 °C had the highest concentration of OVs and showed excellent NRR performance, with the highest NH3 yield (up to 12.28 μg h−1 mgcat−1), high Faraday efficiency (23.04% at −0.30 V vs. RHE), and good stability at −0.40 V vs. RHE, and the catalytic performance was about two times higher than that of Mn2O3 and MoO3. It is also superior to other bimetallic oxide NRR electrocatalysts reported in some cases. In addition, we also explored the ratio between Mn and Mo metals, and the catalytic effect was the best when Mn : Mo = 1 : 1. Due to the synergistic effect between Mn and Mo metals and the large number of OVs present internally, the catalytic activity for the NRR was largely improved. This study suggests that the bimetallic oxide MnMoO4 may be a promising NRR electrocatalyst.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
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IF 14.229
Zishan Han,Changhyeok Choi,Song Hong,Tai-Sing Wu,Yun-Liang Soo,Yousung Jung,Jieshan Qiu,Zhenyu Sun
Renewable energy-driven electrochemical N 2 reduction reaction (NRR) provides a green and sustainable route for NH 3 synthesis under ambient conditions but is plagued by a high reaction barrier and low selectivity. To promote NRR, modification of the catalyst surface to increase N 2 adsorption and activation is key. Here, we show that engineering surface oxygen vacancies of TiO 2 permits significantly enhanced NRR activity with an NH 3 yield rate of about 3.0 μg NH3 h −1 mg cat. −1 and a faradaic efficiency (FE) of 6.5% at -0.12 V ( vs . the reversible hydrogen electrode, RHE). Efficient conversion of N 2 to NH 3 is achieved in a wide applied potential range from -0.07 to -0.22 V ( vs . RHE) with NH 3 production rates ≥ 2.0 μg NH3 h −1 mg cat. -1 and NH 3 FEs ≥ 4.9%, respectively. An NH 3 FE as high as 9.8% is obtained at a low overpotential of 80 mV. Density functional theory calculations reveal that the surface oxygen vacancies in TiO 2 play a vital role in facilitating electrochemical N 2 reduction by activating the first protonation step and also increasing N 2 chemisorption (relative to *H).
研究领域:
材料科学
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电化学
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能源科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
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2019
·Vol. 7
·期 28
·16969-16978
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IF 10.733
Tianxing Wu,Miaomiao Han,Xiaoguang Zhu,Guozhong Wang,Yunxia Zhang,Haimin Zhang,Huijun Zhao
Deeply understanding the electrochemical activation and inactivation processes of an electrocatalyst is critically important for establishing a high-efficiency nitrogen reduction reaction (NRR) to synthesize an NH3 system. Here we report the utilization of a facile vapor-phase hydrothermal (VPH) method to directly grow ultrafine Nb3O7(OH) nanoparticles on commercial carbon fiber cloth (Nb3O7(OH)/CFC) for the NRR. The results demonstrate that the Nb3O7(OH)/CFC can afford an average NH3 yield rate of 622 μg h−1 mgcat.−1 with a high faradaic efficiency (FE) of 39.9% at −0.4 V versus the reversible hydrogen electrode (RHE) in 0.1 M Na2SO4 electrolyte (pH = 6.1) within 30 min of the NRR, surpassing the performance of most recently reported aqueous-based NRR electrocatalysts. The experimental and theoretical calculation results reveal that the in situ electrochemically converted NbO from Nb3O7(OH) during the NRR is the catalytic active phase with a N2 adsorption free energy of −0.97 eV; however with a reaction time over 30 min, the generated active *N atoms in the *N–NH3 → *N + NH3 hydrogenation step during the NRR are thermodynamically favourable for binding to the oxygen vacancies of NbO to form oxygen-containing NbN0.64 with reduced N2 adsorption free energy (−0.32 eV), resulting in significantly decreased NRR activity. Our studies suggest that although NbO possesses high NRR activity, it may not be a suitable NRR electrocatalyst, owing to easy formation of low active niobium oxynitride during the NRR.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
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2021
·
IF 6.901
Chaoqun Ma,Naihua Zhai,Bingping Liu,Shihai Yan
Although the electrochemical N 2 reduction reaction (NRR) to NH 3 provides a promising avenue for artificial N 2 fixation, building of efficient NRR electrocatalysts with high activity and stability remains a tremendous challenge. The combined experimental results and theoretical calculation reveal that MoS 2 with sulfur-vacancy defect (V S -MoS 2 ) is an admirable NRR catalyst. Electrochemical results demonstrate that V S -MoS 2 (5:2) possesses outstanding NRR performances, including a superior NH 3 average yield rate (46.1 × 10 −11 mol s −1 cm −2 at -0.5 V vs reversible hydrogen electrode (RHE)), an excellent faraday efficiency (FE: 4.58% at -0.4 V vs RHE), good electrochemical stability (at least 24 h), and high selectivity (no by-product of N 2 H 4 ). Density functional theory (DFT) calculations demonstrate that the rate determining steps (RDSs) of all V S -MoS 2 (010)-2, V S -MoS 2 (010)-1, and MoS 2 (010) are the first hydrogenation step to form *NNH intermediate, as reflected by the energy barriers of 0.06 eV, 0.20 eV, and 0.93 eV, the significantly charge transfer (1.02 e , 0.45 e vs. 0.41 e ) from two Mo atoms to N 2 , as well as the stretching of N N bond (1.200 Å, 1.140 Å vs. 0.970 Å), respectively. These results reveal that V S -MoS 2 (010)-2 can effectively activate inert N 2 molecule and have the potential application in nitrogen fixation under mild conditions.
研究领域:
材料科学
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电化学
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理论计算
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 45
·期 5
·2488-2495
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IF 3.591
Bin Fang,Junjie Yao,Xiaojun Zhang,Liang Ma,Yaqi Ye,Jiayi Tang,Guifu Zou,Junchang Zhang,Lin Jiang,Yinghui Sun
Electrochemical nitrogen fixation provides an environmentally friendly strategy for producing ammonia (NH3) under ambient conditions. However, an inexpensive and efficient electrocatalyst for the electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions is still needed. Herein, we report an efficient non-noble-metal electrocatalyst consisting of large scaled-up monocrystalline 3R MoS2, which is first utilized as an electrocatalyst for the NRR under ambient conditions. The NRR performance can be optimized via improving the electrochemically active surface area (ECSA) of MoS2. The NH3 yield rate and FE of MoS2-700 reach 8.8 μg h−1 mgcat−1 and 1.9%, respectively. Notably, 3R MoS2-700 shows excellent stability, with the negligible fluctuation of electrocatalytic activity after being recycled seven times. This study may provide a new strategy for structuring efficient electrocatalysts for the NRR.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2020
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IF 7.216
Huimin Liu,Yidan Zhang,Jingshan Luo
Ammonia synthesis by electrocatalytic nitrogen reduction reaction (NRR) is considered as a promising alternative to the Haber−Bosch process. However, due to the extremely low ammonia yield and easily accessible extraneous contamination in the laboratory, NRR study always suffers from fluctuation and variability. Finding and eliminating all kinds of possible extraneous contamination is crucial to evaluate the performance of electrocatalytic ammonia synthesis accurately. In this work, we systematically explored two factors that affect NRR results but are easy to be ignored: the selection of membrane for NRR and the unconscious N-source in NRR catalysts. After series of experiments, we proposed a low-cost and almost pollution-free Celgard 3501 membrane as the separator for NRR to avoid the adsorption and release of ammonia by the membrane. In addition, we proposed a pre-reduction strategy to remove residual or adsorbed NO x contaminants in catalysts. These two solutions will help the community to evaluate the NRR activity more accurately.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Energy
·
2021
·
IF 7.311
Songliang Liu,Shuli Yin,Shiqian Jiao,Hugang Zhang,Ziqiang Wang,You Xu,Xiaonian Li,Liang Wang,Hongjing Wang
Electrochemical N 2 reduction reaction (NRR) under ambient conditions provides sustainable and green pathways; meanwhile, efficient electrocatalysts are strongly required. In this work, we report an interfacial active site strategy to improve the electrocatalytic NRR performance by modification of Au nanowire (Au NW) surface with oxygen-rich tannic acid (TA). Benefiting from their ultrafine one-dimensional nanowire architecture and the TA-modified metallic interface, the TA-Au NWs effectively facilitate the adsorption and activation of reactants. The TA-Au NWs exhibit a large NH 3 yield rate (15.71 μg h −1 mg −1 cat. ) and a high Faraday efficiency of 14.83% at −0.3 V (vs. the reversible hydrogen electrode) in a N 2 -saturated 0.1 M Na 2 SO 4 with an excellent electrochemical durability. This work provides a general surface modification strategy to fabricate highly active NRR electrocatalysts.
研究领域:
材料科学
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电化学
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
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IF 8.1
Jianglin Tu,Jinwang Li,Zhefei Pan,Xun Zhu,Dingding Ye,Yang Yang,Hong Wang,Liang An,Rong Chen,Qiang Liao
Electrocatalytic nitrogen reduction reaction (NRR) represents a promising technology poised to mitigate the high energy consumption and substantial CO 2 emissions inherent in conventional ammonia (NH 3 ) synthesis method. However, sluggish N ≡ N bond dissociation and competitive hydrogen evolution reaction severely impede the NRR. Therefore, it is crucial to rationally design electrocatalysts to achieve efficient NRR. In this work, bismuth (Bi) nanosheets grown on three-dimensional copper foam substrates are synthesized by a simple galvanic replacement reaction and subsequently employed as efficient NRR catalysts. The high catalytic activity of Bi nanosheets for NRR can be attributed to the ultra-thin thickness of 4–6 atomic layers, extensive specific surface area, abundant pore structure as well as enhanced charge transfer. It is shown that Bi nanosheets subjected to a 24-h galvanic replacement reaction exhibit optimal activity, achieving an NH 3 yield of 1.99 μg cm −2 h −1 and a Faradaic efficiency of 4.68 %. In addition, the Bi nanosheets on copper foam demonstrate relatively excellent stability over 12 h of operation. This work introduces a novel approach for developing electrodes via galvanic displacement reactions to enhance the NRR performance.
研究领域:
材料科学
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化学工程
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Jingjing Ding,Chao Huang,Yanhong Lyu,San Ping Jiang,Shuangyin Wang,Jianyun Zheng
Photoelectrochemical nitrogen reduction reaction (PEC NRR) not only is a viable route for the synthesis of green ammonia (NH 3 ) but also facilitates the distributed development and clean utilization of solar energy. Due to the high NH 3 production and faradaic efficiency, lithium (Li)-mediated PEC NRR system has attracted many attentions of the researchers. However, some issues such as limited Li resources, high cost, harsh use requirements and high energy consumption strictly impede the large-scale applications of the system. Here, we have developed cheap and abundant sodium (Na) as an alternative mediator in the process of PEC N 2 -to-NH 3 fixation. An optimum Na-mediated PEC NRR system is demonstrated with an WO x /Si hierarchical photocathode and methanol as a fast proton shuttle, achieving a good NH 3 yield rate of 29.0 μg·h −1 ·cm −2 under 0.9-MPa N 2 /H 2 (97 vol%: 3 vol%) and 0.1-MPa CO 2 at 0.8 V versus Na redox couple (vs. Na + /Na). The addition of WO x layer accelerates the reduction of Na + and enriches a Na layer on the photocathode surface, part of which reacts with N 2 and protons to produce NH 3 . Introducing small amount of CO 2 can reduce the accumulation of “dead” Na and release the Na + to refresh the activity of Na and support the cycle of Na-mediated process. Our work opens a new avenue for efficient solar-powered N 2 -to-NH 3 fixation by utilizing the cycle of Na/Na + .
研究领域:
化学
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能源科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Small Methods
·
2019
·Vol. 3
·期 11
·1900356
·
IF 0
Tongwei Wu,Wenhan Kong,Ya Zhang,Zhe Xing,Jinxiu Zhao,Ting Wang,Xifeng Shi,Yonglan Luo,Xuping Sun
As a sustainable alternative technology to the Haber–Bosch process, electrochemical N 2 reduction offers the hope of directly converting N 2 to NH 3 at ambient conditions. However, its efficiency greatly depends on screening high-active electrocatalysts for the N 2 reduction reaction (NRR). Here, the recent experimental finding that V is an effective dopant to greatly improve the NRR performances of TiO 2 toward ambient N 2 -to-NH 3 fixation with excellent selectivity is reported. In 0.5 m anhydrous lithium perchlorate, V-doped TiO 2 nanorods attain a high Faradic efficiency of 15.3% and a large NH 3 yield of 17.73 µg h −1 mg cat. −1 at −0.40 and −0.50 V versus reversible hydrogen electrode, respectively, rivaling the performances of most reported aqueous-based NRR electrocatalysts. Density function theory (DFT) calculations are performed to gain further insight into the catalytic mechanism.
研究领域:
材料科学
·
化学工程
·
理论计算
✓ 已验证
DOI
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