CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Yong Jiang,Yini Mao,Yimin Jiang,Hao Liu,Wei Shen,Ming Li,Rongxing He
Developing bifunctional electrocatalysts with high activity and long-term stability over the whole pH range is still a great challenge. Herein, the unsupported RuIr alloys are reported as robust electrocatalysts for pH-universal overall water splitting. The as-synthesized Ru 0.5 Ir 0.5 alloy exhibits unexpected low overpotentials of 4, 28, 16 mV for hydrogen evolution reaction (HER) and 160, 176, 248 mV for oxygen evolution reaction (OER) at 10 mA cm −2 in 0.5 M H 2 SO 4 , 1.0 M KOH and 1.0 M PBS solutions, respectively. Especially, the Ru 0.5 Ir 0.5 ||Ru 0.5 Ir 0.5 cell only needs voltages of 1.44, 1.48 and 1.51 V in the three environments to reach the same current density for overall water splitting and can continuously operate for more than 400, 100 and 100 h. Comprehensive studies verify that the excellent electrocatalytic performance of Ru 0.5 Ir 0.5 originates from the uniform arrangement of Ru and Ir atoms in the alloy, which leads to the leaching of an appropriate amount of Ru atoms and thus produces a protective skeleton composed of high valence Ir (IV) to prevent further dissolution of Ru. In addition, the weak coupling between Ru and Ir makes electron transfer from Ir to adjacent Ru as active sites, resulting in optimal adsorption strength for key intermediates.
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
Advanced Energy and Sustainability Research
·
2023
·Vol. 4
·期 9
·2300023
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IF 5.8
Shuai Zhang,Mingzi Sun,Leilei Yin,Siyuan Wang,Bolong Huang,Yaping Du,Chun-Hua Yan
The oxygen evolution reaction (OER) is critical for renewable energy conversion and storage devices. However, the rational design of electrocatalysts with suitably high efficiency and stability in strongly acidic electrolytes remains a major challenge. Herein, a solid-phase synthesis strategy is developed for the preparation of Ir-Ln (Ln = La, Ce, Pr, Nd) alloy nanoparticles with uniform particle size on carbon supports as superior acidic OER catalysts. Tailoring by the rare earth (RE) elements, Ir 2 Pr achieves a maximum mass activity of 2.10 A mg −1 Ir at 300 mV overpotential and stability over 200 h at 10 mA cm −2 in 0.5 m H 2 SO 4 , which is 9.5 and 20 times higher to pure Ir nanoparticles. Furthermore, Ir 2 Pr alloy nanoparticles exhibit excellent durability in strongly acidic electrolytes. Theoretical calculations have confirmed that the OER performances are strongly related to the RE elements in the alloy, where the d-band centers show a consistent trend with the overpotential. Moreover, the highest electroactivity of Ir 2 Pr is attributed to the improved electron transfer by 4 f orbitals and the suitable binding strength of intermediates. Herein, a fundamental understanding of the lanthanide–electrochemical performance relationship is provided and will also inspire the rational design of efficient nanoscale RE alloy electrocatalysts.
研究领域:
材料科学
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电化学
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能源转换与存储
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2018
·Vol. 24
·期 19
·4902-4908
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IF 5.16
Yu-Ping Qiu,Hui Yin,Hao Dai,Li-Yong Gan,Hong-Bin Dai,Ping Wang
Graphical Are two metals better than one? Surface modification of a Ni nanocatalyst by Ir results in remarkably improved catalytic properties towards H 2 generation from N 2 H 4 ⋅ H 2 O. Coupled experimental and theoretical studies reveal that the formation of Ni−Ir alloy on the catalyst surface plays a crucial role in determining the catalytic performance (see figure). Selective decomposition of hydrous hydrazine (N 2 H 4 ⋅ H 2 O) over metal catalysts provides a promising means for onboard or portable hydrogen source applications. Studies on N 2 H 4 ⋅ H 2 O decomposition catalysts mainly focus on the effects of bulk composition and structure on their performances, instead of the surface-composition-dependent properties. Herein, the synthesis of an Ir-modified Ni/ meso -CeO 2 catalyst is reported by using a combination of colloidal solution combustion synthesis and galvanic replacement methods. A combination of structural characterization, control experiments, and DFT calculations reveals that the Ni−Ir alloy resulting from calcination treatment exerts a profound effect on the catalytic properties. The resulting Ni@Ni−Ir/ meso -CeO 2 catalyst shows excellent catalytic performance towards hydrogen generation from N 2 H 4 ⋅ H 2 O, which compares favorably with the Ni−Ir bimetallic catalysts reported to date.
研究领域:
材料科学
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催化化学
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理论计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
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2023
·Vol. 13
·期 25
·17315-17323
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IF 3.9
Zhengyang Cai,Ping Wang,Xianglong Zhao,Xiuming Bu,Jiajia Zhang,Yuhao Chen,Jingcheng Xu,Ya Yan,Aiying Chen,Xianying Wang
The development of low-cost and high-durability bifunctional electrocatalysts is of considerable importance for overall water splitting (OWS). This work reports the controlled synthesis of nickel–iridium alloy derivative nanochain array electrodes (NiIrx NCs) with fully exposed active sites that facilitated mass transfer for efficient OWS. The nanochains have a self-supported three-dimensional core–shell structure, composed of a metallic NiIrx core and a thin (5–10 nm) amorphous (hydr)oxide film as the shell (e.g., IrO2/NiIrx and Ni(OH)2/NiIrx). Interestingly, NiIrx NCs have bifunctional properties. Particularly, the oxygen evolution reaction (OER) current density (electrode geometrical area) of NiIr1 NCs is four times higher than that of IrO2 at 1.6 V vs. RHE. Meanwhile, its hydrogen evolution reaction (HER) overpotential at 10 mA cm−2 (η10 = 63 mV) is comparable to that of 10 wt% Pt/C. These performances may originate from the interfacial effect between the surface (hydr)oxide shell and metallic NiIrx core, which facilitates the charge transfer, along with the synergistic effect between Ni2+ and Ir4+ in the (hydr)oxide shell. Furthermore, NiIr1 NCs exhibits excellent OER durability (100 h @ 200 mA cm−2) and OWS durability (100 h @ 500 mA cm−2) with the nanochain array structure well preserved. This work provides a promising route for developing effective bifunctional electrocatalysts for OWS applications.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 29
·15543-15553
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IF 14.511
Weibin Chen,Yuxin Xie,Xuehui Gao,Lei Li,Zhan Lin
Multiple electronic structure modification is propitious for constructing strong metal–support interaction and then improving the electrocatalytic activity of supported catalysts, yet remains a great challenge due to the lack of facile protocols. Herein, we report a CoIr alloy supported on two dimensional (2D) graphitic-N doped carbon (CoIr@CN) through a one-step annealing process from an Ir-doped 2D Co-MOF, which exhibits a remarkably reduced Ir loading (2.69 wt%) and enhanced electrocatalytic activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Ir plays an essential role of optimizing the properties of metal nanoparticles and simultaneously effecting the calcining process to adjust the N-doping structure, eventually modulating the synergetic effect between alloy nanoparticles and the N-doped carbon support. Owing to the positive effect of such multiple electronic structure optimization, the electron transfer between alloy nanoparticles and N-doped carbon is promoted to enable more moderate adsorption energies of reaction intermediates in both the OER and HER. Impressively, CoIr@CN exhibits a low OER/HER overpotential of 269 mV/70 mV to achieve a current density of 10 mA cm−2 in 1.0 M KOH, and 25 mV in 0.5 M H2SO4 for HER, as well as a negligible decay of catalytic activity after long-term stability measurements for OER/HER. This study offers an effective way for designing strong metal–support interaction through multiple electronic structure modification, which effectively improves the OER/HER performance of supported catalysts.
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
NANO
·
2017
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IF 1.025
Xuedong Gao,Lulu Liu,Qiyu Wang,Kun Qi,Zhao Jin,Weitao Zheng,Xiaoqiang Cui
Nanodendritic Pt-based bimetallic alloys are one promising catalyst with three-dimensional (3D) networks structure composed of integrating branches for electrochemical catalytic reaction. We successfully synthesized dendrites Pt 6 Ir 4 alloy with small size of 20 nm in oleylamine. The dendritic Pt 6 Ir 4 alloy are characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical tests suggest that the as-prepared dendritic Pt 6 Ir 4 alloy exhibits greatly enhanced ethylene glycol oxidation reaction (EGOR) activity than commercial Pt/C with high EGOR mass activity, anti-poisoning and stability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）