ACS Catalysis
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2024
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IF 11.3
Xue Yang,Lu Sun,Xingyu Liu,Zekai Yang,Han Sun,Weiwei Liu,Haijun Chen
The vacancy-engineering strategy has been successfully employed for electrochemical conversion by modulating the electronic structure and reaction kinetics of metal oxide-based electrode materials. The electrolysis of ammonia into hydrogen and nitrogen under mild conditions would be beneficial for utilizing ammonia as a zero-carbon fuel for mobile applications, such as cars and ships. Although platinum has been studied as the most effective state-of-the-art electrocatalyst for ammonia electrolysis, its high cost and rapid deactivation due to nitride poisoning make it difficult to be used commercially. Herein, we report that nanosized cerium oxides (CeOx) demonstrate highly efficient activity and enhanced stability for ammonia electrolysis in a nonaqueous electrolyte system. The Faradaic efficiency of N2 is approximately double that of a commercial Pt/C electrode, while its onset potential is lower than that of the latter. Cerium oxide with vacancy sites was found to be more favorable for NH3 adsorption and exhibits a significantly lower energy barrier for the initial step of NH3 dissociation compared to CeO2. Consequently, this contributes to the heightened activity of ammonia electrolysis on the electrode of cerium oxide following the G–M mechanism.
研究领域:
材料科学
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电化学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
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2014
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IF 0
Min Jiang,Dandan Zhu,Xuebo Zhao
Electrolysis of ammonia in alkaline electrolyte solution was applied for the production of hydrogen. Both Pt-loaded Ni foam and Pt-Ir loaded Ni foam electrodes were prepared by electrodeposition and served as anode and cathode in ammonia electrolytic cell , respectively. The electrochemical behaviors of ammonia in KOH solution were individually investigated via cyclic voltammetry on three electrodes, i.e. bare Ni foam electrode, Pt-loaded Ni foam electrode and Pt-Ir loaded Ni foam electrode. The morphology and composition of the prepared Ni foam electrode were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Effects of the concentration of electrolyte solution and temperature of electrolytic cell on the electrolysis reaction were examined in order to enhance the efficiency of ammonia electrolysis. The competition of ammonia electrolysis and water electrolysis in the same alkaline solution was firstly proposed to explain the changes of cell voltage with the electrolysis proceeding. At varying current densities, different cell voltages could be obtained from galvanostatic curves. The low cell voltage of 0.58 V, which is less than the practical electrolysis voltage of water (1.6 V), can be obtained at a current density of 2.5 mA/cm 2 . Based on some experimental parameters, such as the applied current, the resulting cell voltage and output of hydrogen gas , the power consumption per gram of H 2 produced can be estimated.
研究领域:
能源科学
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催化化学
✓ 已验证
产品关联
DOI
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2016
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IF 3.205
Bao-Xia Dong,Hui Tian,Yi-Chen Wu,Fan-Yan Bu,Wen-Long Liu,Yun-Lei Teng,Guo-Wang Diao
Liquid ammonia electrolysis is conducted out at ambient temperature using different ammonium salt electrolytes with and without the reference electrode. It is determined that electrolytes containing NH 4 + increase the current density and reduce the solution resistance. Moreover, ammonium salts of NH 4 Br, NH 4 NO 3 and NH 4 Cl preserve >80% current efficiency and a 0.6–0.8 mL min −1 average rate of H 2 generation during chronopotentiometry tests at 120 mA cm −2 for 3 h. A minimum electrolysis voltage ( E min ) of ca . 1.2 V is required for the NH 4 Cl electrolyte when using Pt-foil as the anode and cathode . To decrease the overpotential of the anode reaction, five types of electrocatalysts were prepared and characterized: Pt-black, Rh, Pt–Ir, Rh–Pt and Ph–Pt–Ir alloys. Trimetallic Rh–Pt–Ir and bimetallic Pt–Ir, Rh–Pt (1:1) alloy electrodes exhibit a combined benefit of better activity and minimized deactivation. The ternary Rh–Pt–Ir alloy anode shows the best electrocatalytic activity with the lowest E min of ca . 0.47 V and highest current density of 46.9 mA cm −2 at 2.0 V. In comparison with the Pt-foil anode, the E min is reduced by two-thirds, and the current density is increased two-fold.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 13
·8444-8451
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IF 12.732
Qi Xue,Yue Zhao,Jingyi Zhu,Yu Ding,Tiaojiao Wang,Huiying Sun,Fumin Li,Pei Chen,Pujun Jin,Shibin Yin,Yu Chen
Co-regulation of the crystal plane and composition is a powerful strategy to effectively enhance the catalytic properties of nanomaterials. Herein, high-quality PtxRu nanocubes (PtxRu-NCs) with an adjustable composition and exposed (100) planes are synthesized by a simple hydrothermal method. For the ammonia electrooxidation reaction (AOR), Pt6Ru-NCs show obviously higher mass activity (192 mA mgPt−1) and specific activity (1.02 mA cm−2) than other PtxRu-NCs, Pt-NCs and commercial Pt nanocrystals. Density functional theory calculations demonstrate that the Pt6Ru (100) plane is more energetically favourable for the AOR than the Pt (100) plane due to the stronger binding of *NH2 and *NH. For the hydrogen evolution reaction (HER), the optimized Pt6Ru-NCs also deliver the smallest overpotential (37.6 mV) at 10 mA cm−2. The high activity of bifunctional Pt6Ru-NCs for both AOR and HER can be attributed to the crystal surface effect and Pt-Ru bimetallic interactions. A symmetric ammonia electrolyzer constructed here with Pt6Ru-NCs as the cathode and anode only requires 0.72 V electrolysis voltage for electrochemical hydrogen production.
研究领域:
材料科学
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电化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
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IF 6.901
Kun Jiang,Kai Li,Yun-Quan Liu,Shixiang Lin,Zhaolin Wang,Duo Wang,Yueyuan Ye
The generation of hydrogen from water electrolysis has been widely studied as a power-to-gas pathway for the change of energy consumption system, and has attracted a lot of scientific interest over the past several decades. However, the sluggish anodic oxygen evolution reaction (OER) leads to high overpotential in the electrolytic process. Therefore, using ammonia electrolysis to replace water splitting was recently considered as an advisable method for getting pure hydrogen, as ammonia electrocatalytic decomposition is thermodynamically more energy efficient than water splitting. Thus, in this work, a nanostructured transition metal binary (rather than the most widely used noble metals) deposited on nickel foam was developed through a hydrothermal method. The nickel-cobalt bimetallic catalyst was then further fabricated through the nitridation process annealed in an ammonia atmosphere at high temperatures to prepare nickel-cobalt nitride, which substantiated an optimal electrochemical performance on hydrogen evolution reaction (HER) in an alkaline ammonia system. The electrochemical tests indicated that the 1D nanoneedle nickel-cobalt nitride electrode offers favorable surface area and active sites leading to the hydrogen evolution onset potential close to zero, the overpotential 74 mV at 10 mA•cm −2 , 138 mV at 100mA•cm −2 , and the Tafel slope 67 mV/dec. In addition, it also demonstrated an excellent stability in long-term running, with the hydrogen generation rate slightly reduced after 10 h of chronoamperometry measurements. Moreover, the potential of ammonia electrolysis was 0.71 V at 100 mA•cm −2 in a two-electrodes system, lower than that of water splitting, suggesting the hydrogen production from ammonia electrolysis could be a promising alternative to water splitting.
研究领域:
电化学
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材料科学
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能源存储与转换
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）