Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 9
·4807-4815
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IF 11.301
Ying Gu,Aiping Wu,Lei Wang,Dongxu Wang,Haijing Yan,Peng Yu,Ying Xie,Chungui Tian,Fanfei Sun,Honggang Fu
Single-atom catalysts (SACs) have been promising in various catalytic fields, but the controllable synthesis of SACs with high stability remains challenging. Here, we show a robust strategy toward the fabrication of highly efficient and stable SACs based on the “competitive occupancy” of two metal (M) species on graphene oxide (GO). The abundant M1 (Ti) species predominantly occupy more groups of GO, thereby leaving a tiny number of groups in the gaps of the M1 species to combine with M2 (Co2+, etc.) species. Consequently, this guarantees the formation of Co–N4 SACs embedded in 2D TiN/rGO sheets during nitridation. Further, TiN can act as a “spacer” to prevent Co–N4 from aggregation, thereby improving catalyst stability. Co–N4/TiN–rGO exhibits outstanding catalytic performance for the fast conversion of highly concentrated aromatic nitro compounds (∼0.3–2 mM) into amino compounds and excellent recyclability, which is the best among reported catalysts. In contrast, TiN/rGO has no obvious activity, and Co4N–rGO prepared without Ti competition shows poor activity and stability, which indicates the vital role of Co–N4 and TiN for obtaining the remarkable catalytic ability of Co–N4/TiN–rGO. The reaction mechanism is also proposed based on theoretical calculations. The strategy can be used to design Ni (Fe, Cr, Cu)-based SACs.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Small
·
2021
·Vol. 17
·期 12
·2006442
·
IF 13.281
Yan Lv,Xueyan Wu,He Lin,Jiaxin Li,Hongbo Zhang,Jixi Guo,Dianzeng Jia,Hongmei Zhang
Carbon-supported metal nanocatalysts have received substantial attention for heterogeneous catalysis in industry. Hunting for suitable and impactful carbon supports that have strong interactions with metal nanocatalyst is a matter of great urgency. Herein, a well-designed graphdiyne layer decorated on the carbon nanotubes sidewalls (CNT@GDY) serves as a novel carbon support. This unique hybrid structure effectively traps platinum and palladium atomic clusters (Pt/Pd-ACs) with dimensions of 0.65 nm and 1.05 nm uniformly and firmly, forming novel carbon-supported metal nanocatalysts (Pt(Pd)-ACs/CNT @ GDY) for efficient hydrogen generation and aromatic nitroreduction, respectively. The Pt-ACs/CNT@GDY can deliver an HER current density of 10 mA cm −2 with a small overpotential of 23 mV in 0.5 M H 2 SO 4 , showing a greatly enhanced mass activity, intrinsic activity than the commercial Pt/C catalyst. The Pd-ACs/CNT@GDY also exhibits excellent catalytic activity and a high turnover frequency of 38.0 min −1 for aromatic nitroreduction. The carbon support turns out to possess excellent conductivity, abundant and uniform reactive sites, low redox potential, more negative surface and large specific surface area as well as a strong interaction with ACs, as anticipated in ideal supports, which can be applied in other metal-supported catalysts.
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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Fengliang Cao,Qingshan Zhao,Xiaojie Tan,Libo Wang,Yikun Zhao,Wei Deng,Linjie Zhi,Mingbo Wu
Optimizing the local environment of metal active centers bonded by nitrogen ligands (M−N 4 ) through additional axial coordination provides a promising approach to enhance the reaction kinetics of heterogeneous catalysis. However, achieving precise targeting and construction of efficient active sites remains a major challenge. In this study, under the guidance of density functional theory (DFT) calculations, we precisely position and engineer atomic Co–N 4 active sites with axial O coordination on porous carbon nanosheets (Co 1 /NOC) for boosted aromatic nitroreduction through a novel template-anchoring strategy. The resulting Co 1 /NOC catalyst exhibited unprecedented catalytic activities towards a series of functionalized nitroaromatics with a record overall turnover frequency (TOF) of 38022 h −1 under mild reaction conditions, 7.6- and 38 times higher than that of Co–N 4 sites (Co 1 /NC) and commercial Pd/C catalysts, respectively, standing ahead of the reported catalysts. Targeted DFT calculations reveal that axial oxygen coordination efficiently promotes the electronic delocalization of the Co center, which dramatically facilitates the formation and utilization of reactive H* species, enhances the selective adsorption of nitroaromatics, and accelerates the conversion of aromatic nitroreduction, eventually attaining exceptional catalytic performance. This work offers a new avenue for precisely tailoring the coordination environment of single-atom catalysts to achieve advanced catalytic performance in chemical transformations.
研究领域:
催化化学
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材料科学
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2021
·Vol. 9
·期 2
·2101564
·
IF 6.147
Feng Wang,Shuaibo Qin,Botao Zhu,Peng Jin,Jiahao Cai,Yunpeng He,Hailin Cong,Lai Feng
Graphite carbons have been widely used as catalyst support due to their low-cost, tunable porous structure, high electrical conductivity, and good resistance to harsh conditions. To date, various defect engineerings have been adopted to enhance the cohesion between graphite carbons and metallic nanocatalysts. Nevertheless, the modification of carbon basal plane has been less explored. In this work, a dual modification strategy is developed to achieve novel carbon support (denoted as NC f ) incorporating both C 60 units and trace N-defects. Benefiting from the dual anchoring modes (Ru–C and Ru–N–C), ultrafine ruthenium (Ru) nanoclusters (average size: 2.26 ± 0.38 nm) can be well-dispersed and robustly anchored on the NC f support. The optimal Ru 0.013 @NC f catalyst exhibits decent catalytic activities and long-term stabilities toward both alkaline hydrogen evolution reaction (HER) and aromatic nitroreduction (ANR), outperforming the individually modified counterparts. Computational studies suggest that introducing both C 60 and N-defects into carbon support leads to electron-deficient Ru nanocluster, which is critical for not only HER but also ANR. This work thus provides a new guideline for rational design of advanced carbon supported nanocatalysts for multipurpose applications.
研究领域:
催化化学
·
材料科学
✓ 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）