INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Xing Yang,Yongqi Liu,Xiaohui Niu,Ke Chu
Metalloporphyrin ligands themselves can participate in the redox process, making them beneficial in promoting the multielectron catalytic process of the oxygen evolution reaction (OER). However, OER catalysts synthesized by traditional chemical strategies face challenges in water electrolysis. We synthesized high-performance and stable alkaline and acidic OER electrocatalysts loaded with ultrasmall iridium clusters by taking advantage of the attraction and confinement of Ir atoms by the Ir–N bonds formed by the porphyrin cavity. The N in the porphyrin cavity forms an Ir–N bond with Ir so that Ir carries a negative charge and attracts Ir atoms to form ultrasmall Ir clusters above the cavity to adjust the electronic structure of the Ir clusters. The resulting catalyst Tpyp-Ir(IrOX) exhibits a small overpotential (242 and 259 mV) at a current density of 10 mA cm–2 in alkaline and acidic conditions and demonstrates good long-term operational stability. In addition, Tpyp-Ir(IrOX) exhibits a higher transition frequency (TOF) (1.69 O2 s–1 at 300 mV) in 1 M KOH, which is 7 times that of Ir/C.
研究领域:
材料科学
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催化化学
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Binyu Zhang,Weiwei Li,Kexi Zhang,Jingtao Gao,Yang Cao,Yuqian Cheng,Delun Chen,Qiang Wu,Lei Ding,Jinchun Tu,Xiaolin Zhang,Chenghua Sun
Strain engineering of two-dimensional (2D) material interfaces represents a powerful strategy for enhancing the electrocatalytic activity of water splitting. However, maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge. The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets (NSs) derived from metal organic frameworks (Ir@NiO/C BDC ), which displays a high activity and stability under all pH conditions, and even a change of only 1% in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions. Through combined experimental and computational studies, we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/C BDC catalyst, arising from its increased Ir and Ni vacancy formation energies, and hence suppressing its leaching. Moreover, strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by optimizing its electronic structure and coordination environment. This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable 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
Small
·
2023
·Vol. 19
·期 52
·2305343
·
IF 13.3
Yingxiu Zhao,Qiyan Sun,Xinyuan Zhou,Zhiyao Duan,Chuanfang Zhang,Guang-Rui Xu,Dianxing Ju,Lei Wang
Design high-loading with superior activity and high atomic efficiency has consistently been a new frontier of heterogeneous catalysis while challenging in synthetic technology. In this work, a universal solid-state strategy is proposed for large scalable production of high-loading Ir clusters on porous hollow carbon nanobowls (Ir CSs/PHCNBs). The strong electronic interaction between metallic Ir cluster and C on PHCNBs leads to electron redistribution, which significantly improves the electron transfer rate on the interface. The obtained Ir CSs/PHCNBs only require overpotentials of 35, 34, and 37 mV for the hydrogen evolution reaction (HER) with stable outputting of 10 mA cm −2 under acidic, alkaline, and neutral conditions, respectively, which exceeds the state-of-the-art HER electrocatalysts. Meanwhile, the Tafel slopes of Ir CSs/PHCNBs for the HER process are 23.07, 48.76, and 28.95 mV dec −1 , greatly lower than that of PHCNBs (152.73, 227.96, and 140.29 mV dec −1 ) and commercial Pt/C (20%) (36.33, 66.10, and 36.61 mV dec −1 ). These results provide a new strategy for the universal synthesis of clusters catalysts and insight into understanding the interface effects between clusters and carbon substrate, facilitating the industrial application of hydrogen production.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xue Liu,Shaojie Jing,Chaogang Ban,Junjie Ding,Jiangping Ma,Yajie Feng,Youyu Duan,Hanjun Zou,Xiangnan Gong,Kai Zhou,Bin Zhang,Liyong Gan,Xiaoyuan Zhou
Noble metal decoration is one of the most efficient strategies to enhance the activity of electrocatalysts for hydrogen/oxygen evolution reaction (HER/OER). However, there is still lack of a comprehensive picture of how such strategy enhances the activity due to the complicated surface reconstructions and various electronic interactions on electrocatalysts during reactions, severely hampering the widespread utilizations of this strategy. Herein, we report that decorating Ir clusters on Fe doped Ni 2 P (Ir@Ni 2 P(Fe)) can reinforce the reconstruction of Ni 2 P(Fe) to generate more real active species via promoting the leaching of P element and ultimately improve the activities for both HER and OER. Specifically, such reinforcement leads to a considerably enhanced electron transfer and a substantially increased amount of active sites, ultimately playing a dominant role in boosting the HER performance from 176 mV over Ni 2 P(Fe) to 35 mV over Ir@Ni 2 P(Fe) at 10 mA cm −2 . As for OER, in addition to increasing the amount of active sites via the reinforcement, the decoration of Ir clusters provides high-valence Ir sites as extra efficient active centers, thereby resulting in dual promotional effects to enhance the activity from 270 to 200 mV at 10 mA cm −2 . Finally, using Ir@Ni 2 P(Fe) as both the anode and cathode, a low cell voltage of 1.50 V is required to derive a current density of 10 mA cm −2 for overall water splitting. The developed comprehensive insight is of clear significance to design advanced bifunctional electrocatalysts for overall water splitting.
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 Materials
·
2022
·Vol. 13
·期 1
·2202913
·
IF 29.698
Dan-Qing Liu,Zhouxin Luo,Bingxing Zhang,Guoqiang Zhao,Wei Guo,Jian Chen,Mingxia Gao,Yongfeng Liu,Hongge Pan,Wenping Sun
The sluggish kinetics of hydrogen oxidation reaction (HOR) is one of the critical challenges for anion exchange membrane fuel cells. Here, we report epitaxial growth of Ir nanoclusters (<2 nm) on a MoS 2 surface (Ir/MoS 2 ) and optimize the alkaline HOR activity via tailoring interfacial charge transfer between Ir clusters and MoS 2 . The electron transfer from MoS 2 to Ir clusters can effectively prevent the oxidation of Ir clusters, which is not the case for carbon-supported Ir nanoclusters (Ir/C) synthesized using the same method. Moreover, the HOR performance of the Ir/MoS 2 can be further optimized by tuning the hydrogen binding energy (HBE) via a precise annealing treatment. A substantial exchange current density of 1.28 mA cm ECSA −2 is achieved in the alkaline medium, which is ∼10 times over that of Ir/C. The HOR mass-specific activity of Ir/MoS 2 heterostructure is as high as 182 mA mg Ir −1 . The experimental results and density functional theory calculations reveal that the significant improved HOR activity is attributed to the decreased HBE, which highlights epitaxial growth is an effective way for boosting catalytic activity of heterostructured catalysts.
研究领域:
材料科学
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电化学
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催化
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燃料电池技术
✓ 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）