INORGANIC CHEMISTRY COMMUNICATIONS
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2022
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IF 3.428
Yao Tian,Chunmei Zeng,Shiyu Yang,Yang Luo,Lunhong Ai,Jing Jiang
Development of efficient and economical non-precious metal catalysts for dehydrogenation of ammonia borane is an important way to store and release hydrogen. Vacancy-engineered defective catalysts with modulated electronic structure allow ideal adsorption and dissociation of reactant molecules for the optimized catalytic activity. In this study, we report a facile synthesis of cobalt-defective Co 3 O 4 (V Co -Co 3 O 4 ) nanocatalyst by the calcination of layered cobalt glycerate as a key precursor. The stacked cobalt-oxygen sheets and interlayer bound glycerate anions in a layered structure are favorable for introducing cation vacancy during calcination process. The obtained V co -Co 3 O 4 exhibits outstanding catalytic activity for the hydrolysis of ammonia borane, along with a high hydrogen production rate of 934 mL min −1 g Cat -1 and a low activation energy of 32.65 kJ mol −1 . The catalytic performance of the V Co -Co 3 O 4 catalyst can be well maintained for consecutive five cycles. The current study establishes a new example of cation vacancy strategy to facilitate the hydrolysis of ammonia borane for hydrogen generation.
研究领域:
材料科学
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催化化学
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能源存储与转换
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Yuexi Zheng,Zhiguo Ye,Xinyuan Peng,Shaojie Zhuang,Duosheng Li,Zhong Jin
Oxygen evolution reaction (OER) electrocatalysts in acidic media, except for precious IrO 2 , have difficulty realizing good electrocatalytic activity and high electrochemical stability simultaneously. However, the scarcity of IrO 2 as an acidic OER electrocatalyst impedes its large-scale application in hydrogen generation, organic synthesis, nonferrous metal production and sewage disposal. Herein, we report the design and fabrication of a nanoporous TiMnCoCN compound based on the nanoscale Kirkendall effect, possessing an intriguing self-adjusting capability for the oxygen evolution reaction (OER) in a 0.5 M H 2 SO 4 solution. The nanoporous TiMnCoCN compound electrode for the acidic OER displays a low overpotential of 143 mV for 10 mA cm −2 and exhibits no increase in potential over 50,000 s, which is ascribed to the self-adjusting ability, Carbon/nitrogen (C/N) incorporation and nanoporous architecture. The concentration of inert TiO 2 on the reconstructed surface of the compound can self-adjust with the change in OER potential via a cobalt-dissolved vacancy approach according to the stabilization requirement. In this work, the self-reconstruction law of surface structure was discovered, providing a novel strategy for designing and fabricating nonnoble OER electrocatalysts with superior catalytic performance and robust stability in acidic media.
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
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Zhiqin Deng,Chaoqun Ma,Zerong Li,Yongsong Luo,Longcheng Zhang,Shengjun Sun,Qian Liu,Juan Du,Qipeng Lu,Baozhan Zheng,Xuping Sun
Electrocatalytic nitrate reduction reaction (NO3RR) affords a bifunctional character in the carbon-free ammonia synthesis and remission of nitrate pollution in water. Here, we fabricated the Co3O4 nanosheet array with cobalt vacancies on carbon cloth (vCo-Co3O4/CC) by in situ etching aluminum-doped Co3O4/CC, which exhibits an excellent Faradaic efficiency of 97.2% and a large NH3 yield as high as 517.5 μmol h–1 cm–2, better than the pristine Co3O4/CC. Theoretical calculative results imply that the cobalt vacancies can tune the local electronic environment around Co sites of Co3O4, increasing the charge and reducing the electron cloud density of Co sites, which is thus conducive to adsorption of NO3– on Co sites for greatly enhanced nitrate reduction. Furthermore, the vCo-Co3O4 (311) facet presents excellent NO3RR activity with a low energy barrier of about 0.63 eV on a potential-determining step, which is much smaller than pristine Co3O4 (1.3 eV).
研究领域:
电化学
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催化
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICA B-CONDENSED MATTER
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2022
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IF 2.988
Wei Zhang,Zhiwei Gu,Bingbing Zong,Yueju Fu,Kai Zhang,Yubao Li
Defects is of special importance in tuning the structure and physical properties of layered materials. Here the influence of transition metal Co vacancies on the structure and magnetism in collapsed tetragonal CaCo 2- x As 2 (0 ≤ x ≤ 0.3) solid solutions are systematically investigated. The electrical properties show metallicity in all compounds. The crystal structure refinement exhibits that the lattice constant of the c axis and c / a ratio decreases as Co vacancies increase, revealing the formation of a more collapsed tetragonal structure in CaCo 2- x As 2 . Moreover, these introduced Co vacancies suppress the antiferromagnetic Néel temperature from 80 K down to 18 K until it disappears above 10 K in CaCo 1 · 7 As 2 . X-ray photoelectron spectroscopy reveals increased Co 3+ /Co 2+ value in CaCo 2- x As 2 with higher Co vacancies, which may result in the charge balance and the gradually suppressed T N . This study offers insights into tuning and understanding the magneto-structural characteristics in ThCr 2 Si 2 -type layered materials through transition metal vacancies.
研究领域:
凝聚态物理
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材料科学
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固体化学
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磁学
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晶体工程
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缺陷工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）