Molecular Catalysis最新文献_第8页

The active site of Mδ+ tailed by B (or N)-doped graphyne for nitrogen reduction reaction through DFT study 通过 DFT 研究 B（或 N）掺杂石墨烯尾 Mδ+ 的活性位点用于氮还原反应

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-28 DOI: 10.1016/j.mcat.2024.114576

Yuzhen Fang , Lin Teng , Weihong Li , Hailun Ren , Dongting Wang , Suhong Lu , Pengpeng Hao

NN bond activation is one of the technical problems in the conversion of N₂-to-NH₃. In this work, we researched Cr, Mn, Co, Ni, Cu and Pt metal single atoms anchored on B/N-doped graphyne (M/X-GY) catalysts systematically by means of DFT. The results of Bader charge and charge density verified the charge transfers between single metal and the doped graphyne in M/X-GY catalysts. Cr (+1.001 e) and Mn (+0.800 e) exhibit higher positive valence, which is favorable for N₂ adsorption. Based on the "donation and back-donation" mechanism, the energies gaps of 5σ-N₂ and d-M for M=Cr, Mn and Co have the lower values of 3.01, 3.18, 3.18 eV, respectively, and the N₂ adsorption energies on Cr/GY (−2.046 eV) and Mn/GY (−1.622 eV) have the more negative values. As a result, the catalyst of Cr metal atom anchored on GY is promising candidate. The substitution of B can effectively promote the activation of N₂ and suppress the hydrogen evolution, while the substitution of N has the minimum ΔG_*N-NH of 0.26 eV and ΔG_NH3 of 0.08 eV. Compared with two different NRR pathways, the distal mechanism process is more preferential than the alternating pathway. The catalyst of Cr/N-GY has higher stability and can effectively activate N₂ to generate *N₂H, which can serves as promising catalysts throughout the NRR process.

NN 键活化是 N2 转化为 NH3 的技术难题之一。在这项工作中，我们通过 DFT 系统地研究了锚定在掺杂 B/N 的石墨烯（M/X-GY）上的 Cr、Mn、Co、Ni、Cu 和 Pt 金属单原子。巴德电荷和电荷密度的结果验证了 M/X-GY 催化剂中单个金属和掺杂石墨之间的电荷转移。铬（+1.001 e）和锰（+0.800 e）表现出较高的正价，有利于 N2 的吸附。基于 "捐献和反捐献 "机理，M=Cr、Mn 和 Co 的 5σ-N2 和 d-M 的能隙分别为 3.01、3.18 和 3.18 eV，且 Cr/GY （-2.046 eV）和 Mn/GY （-1.622 eV）上的 N2 吸附能为负值。因此，Cr 金属原子锚定在 GY 上的催化剂是很有前景的候选催化剂。B 的取代能有效促进 N2 的活化并抑制氢的进化，而 N 的取代具有最小的 ΔG*N-NH 0.26 eV 和 ΔGNH3 0.08 eV。与两种不同的 NRR 途径相比，远端机制过程比交替途径更优。Cr/N-GY催化剂具有更高的稳定性，并能有效活化N2生成*N2H，可在整个NRR过程中发挥催化剂的作用。

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引用次数: 0

Activity of CeO2(111) supported Mnx(x = 1–6) for electrochemical N2 reduction reaction: Insights from density functional theory Mnx（x = 1-6）支撑的 CeO2（111）在电化学 N2 还原反应中的活性：密度泛函理论的启示

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-28 DOI: 10.1016/j.mcat.2024.114582

Heng Cao, Shulan Zhou

It is challenging to realize an efficient nitrogen reduction reaction (NRR) under mild conditions, which suffers from low ammonia yield and low Faraday efficiency due to the extremely stable NN triple bond of N₂ as well as competitive hydrogen evolution reaction. In this work, the NRR reactivity of Mn_x(x = 1–6) clusters supported on CeO₂(111) (Mn_x(x = 1–6)/CeO₂(111)) was systematically investigated using density functional theory. A volcanic relationship between the limiting potential of NRR on Mn_x(x = 1–6)/CeO₂(111) and the atom number of Mn_x was found. Mn₃/CeO₂(111) shows the highest activity for NRR with a limiting potential of -0.36, -0.55 and -0.53 V along distal, alternating and enzymatic reaction pathway, respectively. Its high activity is attributed to the triangular geometry and optimal average number of electrons every Mn transferred from Mn₃ to CeO₂(111), which leads to the strong N₂ activation and the stabilization of nitrogen-containing intermediates. Also, Mn₃/CeO₂(111) exhibits a high NRR selectivity by hindering H adsorption and a high thermal stability at both 298 and 773 K, suggesting its promising potential as effective NRR catalyst. This work provides new insights into the rational design of single cluster catalysts.

在温和条件下实现高效的氮还原反应（NRR）具有挑战性，由于 N2 的 NN 三键极其稳定以及竞争性氢进化反应，该反应存在氨产量低和法拉第效率低的问题。本研究利用密度泛函理论系统研究了 Mnx(x = 1-6) 团簇在 CeO2(111) （Mnx(x = 1-6)/CeO2(111) ）上的 NRR 反应性。研究发现，Mnx(x = 1-6)/CeO2(111)上 NRR 的极限电位与 Mnx 的原子数之间存在火山关系。Mn3/CeO2(111)显示出最高的 NRR 活性，在远端、交替和酶反应途径上的极限电位分别为 -0.36、-0.55 和 -0.53V。其高活性归因于三角形几何结构以及从 Mn3 转移到 CeO2(111) 的每 Mn 平均电子数最多，这导致了 N2 的强活化和含氮中间产物的稳定。此外，Mn3/CeO2(111)通过阻碍 H 的吸附而表现出较高的 NRR 选择性，并且在 298 和 773 K 下均具有较高的热稳定性，这表明它有望成为有效的 NRR 催化剂。这项工作为单簇催化剂的合理设计提供了新的见解。

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引用次数: 0

Aerobic oxidation of lignin model compounds catalyzed by the iron or copper/ABNO at room temperature with ambient air as the oxidant 铁或铜/ABNO 在室温下以环境空气为氧化剂催化木质素模型化合物的有氧氧化作用

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-28 DOI: 10.1016/j.mcat.2024.114565

Shaowei Liu, Shuxiao Huo, Xiangzhu Yu, Meng Miao, Lianyue Wang

Herein, we report a simple, efficient, and mild Fe(NO₃)₃·9H₂O or Cu(NO₃)₂·3H₂O/ABNO- catalytic system (ABNO=9-azabicyclo[3.3.1]nonane-N-oxyl), which was capable of oxidizing β-O-4 alcohol lignin model compounds to ketones at room temperature using ambient air as the oxidant. This versatile catalytic system exhibits excellent substrate scope and the corresponding products were obtained in good to excellent yields. The kinetic isotope effect shows that the CH bond breaking is the rate-determining step of the reaction. The experiment of gram scale proves that the catalytic system has good practicability.

在此，我们报告了一种简单、高效、温和的 Fe(NO3)3-9H2O 或 Cu(NO3)2-3H2O/ABNO- 催化体系（ABNO=9-氮杂双环[3.3.1]壬烷-N-氧代），该体系能够在室温下以环境空气为氧化剂将 β-O-4 醇木质素模型化合物氧化为酮。这种多功能催化体系具有极佳的底物范围，并能以良好甚至极佳的收率获得相应的产物。动力学同位素效应表明，CH 键断裂是反应的决定性步骤。克级实验证明该催化体系具有良好的实用性。

引用次数: 0

ZIF-67-derived Co3O4@CN-assisted g-C3N4 for efficient photocatalytic hydrogen peroxide production ZIF-67 衍生 Co3O4@CN 辅助 g-C3N4 用于高效光催化过氧化氢生产

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-28 DOI: 10.1016/j.mcat.2024.114584

Heng Chen, Longhui Nie, Yiqiong Yang, Caihong Fang, Xingru Chen, Xueling Li

The conversion of solar energy into chemical energy can be realized by photocatalytic technology, which is also used for hydrogen peroxide (H₂O₂) production because of its clean and eco-friendly properties. Here, g-C₃N₄ (GCN) was coupled with the ZIF-67 derivate (Co₃O₄@CN) by a thermal treatment to obtain the ZCN-X (X = 5, 10, 15 mg of ZIF-67) composite photocatalyst for H₂O₂ production for the first time. ZCN-10 showed the optimal photocatalytic H₂O₂ production efficiency of 531.1 μM (or 2655.3 µmol⋅g^-1⋅h^-1) in one hour, which was 3.49 times that of GCN (152.0 μM). ZCN-10 also showed relatively good stability of photocatalytic H₂O₂ production with a slight decrease after five cycles. The introduction of Co₃O₄@CN on GCN increases the catalyst's specific surface area, visible light adsorption, surface-adsorbed oxygen content, and separation efficiency of photogenerated carriers, which jointly cause a large increase in photocatalytic H₂O₂ production. The mechanism for H₂O₂ production was proved to be a two-step one-electron oxygen reduction reaction (ORR) pathway. This work would shed light on the fabrication of g-C₃N₄-based photocatalysts with high performance for H₂O₂ production.

光催化技术可将太阳能转化为化学能，由于其清洁环保的特性，也可用于生产过氧化氢（H2O2）。在这里，g-C3N4（GCN）与 ZIF-67 衍生物（Co3O4@CN）通过热处理耦合，首次获得了用于生产 H2O2 的 ZCN-X（X = 5、10、15 毫克 ZIF-67）复合光催化剂。ZCN-10 在一小时内的最佳光催化 H2O2 生成效率为 531.1 μM（或 2655.3 µmol-g-1-h-1），是 GCN（152.0 μM）的 3.49 倍。ZCN-10 在光催化产生 H2O2 方面也表现出较好的稳定性，但在五个周期后略有下降。在 GCN 上引入 Co3O4@CN 增加了催化剂的比表面积、可见光吸附量、表面吸附氧含量和光生载流子的分离效率，共同导致光催化 H2O2 产率的大幅提高。H2O2 生成的机理被证明是两步单电子氧还原反应（ORR）途径。这项工作将为制备高性能的 g-C3N4 基光催化剂提供启示。

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引用次数: 0

Synthesis of Pyrrolo [2,1-a]isoquinolines using Cu NPs decorated microcrystalline cellulose in 2-Methyl-THF: A biodegradable heteregeneous nanocatalyst for the sustainable cascade approach 在 2-Methyl-THF 中使用 Cu NPs 装饰微晶纤维素合成吡咯并[2,1-a]异喹啉类化合物：一种可生物降解的、可持续级联方法的恒定纳米催化剂

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-28 DOI: 10.1016/j.mcat.2024.114569

Pranav S. Shrivastav , Nandish Talpada , Anuj S. Sharma , Vinay S. Sharma , Rahul Ahmed , Achalkumar Ammathnadu Sudhakar , Rajender S. Varma

Copper nanoparticles (Cu NPs) supported on microcrystalline cellulose (MCC) serve as an efficient and biodegradable heterogeneous nanocatalyst for the synthesis of pyrrolo [1,2a] isoquinoline under mild and sustainable reaction conditions through a cascade reaction involving condensation, addition, oxidation, and cyclization events. The catalyst underwent thorough characterization via various techniques, including FT-IR, PXRD, XPS, FE-SEM, EDX, TEM, and HR-TEM analysis. Optimized reaction conditions facilitated high-yield production of a diverse range of pyrrolo [1,2a] isoquinolines in 2-Me THF solvent, and the method demonstrated scalability with successful gram-scale synthesis. Notably, the catalyst exhibited reusability for up to five cycles without a significant decrease in activity. This approach aligns with eco-friendly principles, as evidenced by favorable green chemistry metrics for compound 4a, including low process mass intensity (7.83), a minimal environmental impact factor (6.83), a substantial atom economy (67.56 %), efficient reaction mass efficiency (60.76 %), high chemical yield (92.37 %), low mass intensity (1.64), notable mass productivity (60.97 %), considerable carbon efficiency (69.15 %), and optimum efficiency (89.93 %). These results highlight the sustainable and environmentally conscious nature of the developed synthetic methodology.

以微晶纤维素（MCC）为载体的铜纳米颗粒（Cu NPs）是一种高效、可生物降解的异相纳米催化剂，可在温和、可持续的反应条件下，通过涉及缩合、加成、氧化和环化反应的级联反应合成吡咯并[1,2a]异喹啉。催化剂通过各种技术进行了全面表征，包括傅立叶变换红外光谱、PXRD、XPS、FE-SEM、EDX、TEM 和 HR-TEM 分析。优化后的反应条件有助于在 2-Me THF 溶剂中高产生产出各种吡咯并[1,2a]异喹啉类化合物，该方法还具有可扩展性，成功实现了克级合成。值得注意的是，催化剂可重复使用长达五个周期，而活性不会显著降低。这种方法符合生态友好原则，化合物 4a 具有良好的绿色化学指标，包括工艺质量强度低（7.83）、环境影响因子最小（6.83）、原子经济性高（67.56%）、反应质量效率高（60.76%）、化学收率高（92.37%）、质量强度低（1.64）、质量生产率高（60.97%）、碳效率高（69.15%）和效率最佳（89.93%）。这些结果凸显了所开发合成方法的可持续性和环保意识。

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引用次数: 0

Exploring the potential of cobalt-based catalysts in the methane dry reforming for sustainable energy applications 探索钴基催化剂在甲烷干转化过程中的潜力，促进可持续能源应用

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-28 DOI: 10.1016/j.mcat.2024.114575

Yelisbeth Escalante , M. Noelia Barroso , Ana M. Tarditi , John Múnera

Cobalt-based powder catalysts with different Co loadings were synthesized via wet impregnation using MgAl₂O₄ spinel as support. The catalytic properties of the solids were evaluated in the dry-reforming methane at different reaction temperatures and two CH₄:CO₂ ratios. The catalyst with higher cobalt content (13 %) presented superior performance due to increased Co⁰ species availability, confirmed by XPS analysis. Besides, this catalyst displayed remarkable resistance to carbon deposition at 550 °C and CH₄:CO₂ 1: 1 ratio. In-situ DRIFT measurements demonstrated the formation and transformation of carbonate and hydrogen carbonate species during the DRM reaction, highlighting efficient CO₂ and CH₄ activation on the catalyst surface. Based on this data, a structured catalyst was deposited on top of the FeCrAlloy monolith, which was active, stable, selective for H₂, and resistant against on/off cycles. Compared with the powder catalyst, the structured system displayed higher catalytic activity, possibly due to higher reducibility of metal species and improved heat transfer provided by the FeCrAlloy substrate. The results highlight the potential of Co-based structured catalysts for H₂ or synthesis gas production processes.

以 MgAl2O4 尖晶石为载体，通过湿法浸渍合成了不同 Co 负载的钴基粉末催化剂。在不同的反应温度和两种 CH4:CO2 比率下，对固体催化剂在甲烷干转化过程中的催化性能进行了评估。经 XPS 分析证实，钴含量较高（13%）的催化剂由于增加了 Co0 物种的可用性而表现出更优越的性能。此外，在 550 °C 和 CH4:CO2 比例为 1:1 的条件下，这种催化剂显示出显著的抗碳沉积能力。原位 DRIFT 测量结果表明，在 DRM 反应过程中碳酸盐和碳酸氢盐物种的形成和转化，凸显了催化剂表面对 CO2 和 CH4 的高效活化。根据这些数据，在铁铬合金整体上沉积了一种结构催化剂，这种催化剂具有活性、稳定性、对 H2 的选择性和耐开关循环性。与粉末催化剂相比，结构化系统显示出更高的催化活性，这可能是由于金属物种的还原性更高，以及铁铬合金基底提供了更好的热传导。研究结果凸显了 Co 基结构催化剂在 H2 或合成气生产过程中的应用潜力。

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引用次数: 0

CTAB-assisted radio frequency discharge plasma treatment enhances catalytic activity at sustained coking resistance of Nickel-based catalysts for CO2/CH4 reforming reaction CTAB 辅助射频放电等离子体处理提高了镍基催化剂的催化活性，使其在二氧化碳/CH4 重整反应中具有持续的抗结焦性

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-27 DOI: 10.1016/j.mcat.2024.114557

Fang Guo , Renhao Zhang , Wuyi Cao , Hongmei Liu , Kuang-Hsu Wu , Junqiang Xu

Carbon deposition or ‘coking’ reaction severely suppresses catalyst activity during the dry reforming reaction of methane (DRM). The MCM-41-loaded nickel catalyst (NM-C) prepared using the conventional impregnation method also faces these issues. In response, this study investigates a novel catalyst preparation approach employing N₂ radio frequency (RF) discharge plasma coupled with surfactant (cetyltrimethylammonium bromide or CTAB) modification. Characterization of the resulting materials was conducted utilizing XRD, H₂-TPR, CO₂-TPD, TEM, XPS, TG-DTA, and other analytical techniques. Experimental findings reveal that both CTAB addition (NM-CTAB-C) and plasma-assisted catalyst preparation (NM-PN2h) outperform the conventional NM-C catalyst in the DRM. Notably, the catalyst prepared by the CTAB-assisted plasma method (NM-CTAB-PN2h) demonstrates significantly enhanced performance, with initial CH₄ and CO₂ conversions of 84.82% and 85.02%, respectively, at 700 °C. Compared to NM-C, NM-CTAB-PN2h exhibits improvements of 24.8% and 19.9% in CH₄ and CO₂ conversions, respectively. The Ni grain size of NM-CTAB-PN2h (4.9 nm) is notably smaller than NM-C (18 nm), indicating enhanced resistance to coking and stability during CO₂ and methane dry reforming. After 20 h of reaction, NM-CTAB-PN2h maintains a particle size of 6.3 nm, significantly smaller than NM-C (21.4 nm). Moreover, NM-CTAB-PN2h exhibits remarkable resistance to carbon accumulation, with only a 2.36% weight loss compared to 23.38% for NM-C after 20 h at 700 °C. Utilization of CTAB-assisted plasma reduces Ni grain size, enhances metal-support interaction, and increases oxygen vacancies, thus improving dry reforming performance.

在甲烷干转化反应（DRM）过程中，碳沉积或 "结焦 "反应严重抑制了催化剂的活性。采用传统浸渍法制备的 MCM-41 负载镍催化剂 (NM-C) 也面临这些问题。为此，本研究采用 N2 射频 (RF) 放电等离子与表面活性剂（十六烷基三甲基溴化铵或 CTAB）改性相结合的新型催化剂制备方法。利用 XRD、H2-TPR、CO2-TPD、TEM、XPS、TG-DTA 和其他分析技术对所得材料进行了表征。实验结果表明，添加 CTAB（NM-CTAB-C）和等离子体辅助催化剂制备（NM-PN2h）在 DRM 中的性能均优于传统的 NM-C 催化剂。值得注意的是，采用 CTAB 辅助等离子体法制备的催化剂（NM-CTAB-PN2h）性能显著提高，在 700 °C 时，CH4 和 CO2 的初始转化率分别为 84.82% 和 85.02%。与 NM-C 相比，NM-CTAB-PN2h 的 CH4 和 CO2 转化率分别提高了 24.8% 和 19.9%。NM-CTAB-PN2h 的镍晶粒尺寸（4.9 nm）明显小于 NM-C（18 nm），这表明它在二氧化碳和甲烷干转化过程中具有更强的抗结焦性和稳定性。反应 20 小时后，NM-CTAB-PN2h 的粒径保持在 6.3 纳米，明显小于 NM-C（21.4 纳米）。此外，NM-CTAB-PN2h 还具有显著的抗积碳能力，在 700 °C 下反应 20 小时后，其重量损失仅为 2.36%，而 NM-C 则为 23.38%。利用 CTAB 辅助等离子体可减小镍晶粒尺寸，增强金属与支撑物之间的相互作用，并增加氧空位，从而提高干重整性能。

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引用次数: 0

Organocatalysts for L-Lactide polymerization: 2-alkyl- and 2-aryl-1,1,3,3-tetramethylguanidines 用于 L-内酯聚合的有机催化剂：2-烷基和 2-芳基-1,1,3,3-四甲基胍

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-26 DOI: 10.1016/j.mcat.2024.114580

Rajiv Kamaraj , Prasanna Kumar Ganta , Taoufik Ben Halima , Fei Huang , Venkata Sai Sashankh Penki , Hsi-Ching Tseng , Shangwu Ding , Hsuan-Ying Chen , Hsing-Yin Chen

A series of 2-alkyl- and 2-aryl-1,1,3,3-tetramethylguanidine derivatives were synthesized, and their application in L-Lactide (LA) polymerization was studied. Bn-TMG was the best catalyst in LA polymerization ( [Bn-TMG] = 5 mM, conversion = 94 % after 4 h at 25 °C) compared to other monoguanidine derivatives. In addition, the catalytic activities of C2-dTMG exhibited higher catalytic activity than Bn-TMG, ⁿBu-TMG (monoguanidine derivatives), and C3-dTMG (diguanidine derivative). Density functional theory calculations revealed that Bn-TMG deprotonated benzyl alcohol enhanced benzyl alcohol's initiation ability to LA, and the protonated Bn-TMG activated LA ring-opening process by interacting with the ether oxygen atom of LA. Bn-TMG presented excellent catalytic activity and controllability for LA polymerization at 25 °C.

研究人员合成了一系列 2-烷基和 2-芳基-1,1,3,3-四甲基胍衍生物，并研究了它们在 L-内酰胺（LA）聚合中的应用。与其他单胍衍生物相比，Bn-TMG 是 LA 聚合过程中的最佳催化剂（[Bn-TMG] = 5 mM，25 °C 下 4 小时后转化率 = 94 %）。此外，C2-dTMG 的催化活性高于 Bn-TMG、nBu-TMG（单胍衍生物）和 C3-dTMG（二胍衍生物）。密度泛函理论计算表明，Bn-TMG 对苯甲醇的去质子化作用增强了苯甲醇对 LA 的引发能力，质子化的 Bn-TMG 通过与 LA 的醚氧原子相互作用激活了 LA 的开环过程。Bn-TMG 在 25 °C 下对 LA 聚合具有优异的催化活性和可控性。

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引用次数: 0

Pd nanoparticles immobilized by a MOF-derived CeO2/C for boosting ethylene glycol electrooxidation 利用 MOF 衍生的 CeO2/C 固定钯纳米颗粒促进乙二醇电氧化

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-25 DOI: 10.1016/j.mcat.2024.114578

Shengya Ge , Chenzhang Li , Peiyan Bi , Wei Hong

The operation of direct ethylene glycol fuel cells (DEGFCs) to generate electric energy from ethylene glycol rely on the effective electrocatalysts for the ethylene glycol oxidation reaction (EGOR). The fabrication of EGOR electrocatalysts with high activity, high durability and high resistance for corrosion, is essential important for the DEGFCs. Herein, we report a fabrication of Pd nanoparticles immobilized by the Ce-doped ZIF-67-derived carbon (Pd-CeO₂/ZDC). The Pd nanoparticles are generated by the in-situ reduction reaction between the H₂PdCl₄ and the Co nanoparticles formed during the ZIF-67 pyrolysis. Owe to the porous structure and N-doping inherited from the ZIF-67, the Pd and CeO₂ nanoparticles show a uniform distribution. Due to the enhanced EGOR electrooxidation kinetic promoted by the ZIF-67-derived support, the multiple-components and structure synergies, the resultant Pd-CeO₂/ZDC catalyst affords a EGOR current density of 32.4 mA cm^-2, which is higher than the commercial Pd/C as well as the counterpart Pd/ZDC catalyst without CeO₂. Furthermore, the Pd-CeO₂/ZDC catalyst also present a better EGOR durability. This work provides a strategy for the design of EGOR catalyst with multiple-components and desired structure, which may inspire the new tactics for controllable design and synthesis of other electrocatalysts for various electrocatalysis.

利用乙二醇产生电能的直接乙二醇燃料电池（DEGFC）的运行依赖于乙二醇氧化反应（EGOR）的有效电催化剂。制备具有高活性、高耐久性和高耐腐蚀性的乙二醇氧化反应电催化剂对 DEGFCs 至关重要。在此，我们报告了用掺杂铈的 ZIF-67 衍生碳（Pd-CeO2/ZDC）固定钯纳米粒子的制备方法。钯纳米颗粒是由 H2PdCl4 与 ZIF-67 热解过程中形成的 Co 纳米颗粒发生原位还原反应生成的。由于 ZIF-67 的多孔结构和 N 掺杂，钯和 CeO2 纳米粒子呈现均匀分布。由于 ZIF-67 衍生载体促进了 EGOR 电氧化动力学的增强，以及多组分和结构的协同作用，所生成的 Pd-CeO2/ZDC 催化剂的 EGOR 电流密度为 32.4 mA cm-2，高于商用 Pd/C 催化剂和不含 CeO2 的 Pd/ZDC 催化剂。此外，Pd-CeO2/ZDC 催化剂还具有更好的 EGOR 耐久性。这项工作为设计具有多组分和理想结构的 EGOR 催化剂提供了一种策略，可为可控设计和合成用于各种电催化的其他电催化剂提供新的启发。

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引用次数: 0

Environment-friendly heterogeneous poly(ionic liquid)s immobilized polyoxometalate catalysts towards the efficient oxidation of alkenes 高效氧化烯烃的环境友好型多相固定聚（离子液体）聚氧化金属催化剂

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis

Pub Date : 2024-09-25 DOI: 10.1016/j.mcat.2024.114572

Qiao Liu , Meirong Kang , Weiguo Fang , Hailong Liu , Zhiwei Huang

A novel quaternization reagent of (1E,1′E)-1,1′-(1,4-phenylene)bis(N-(3-(1H-imidazol-1-yl)propyl)methanimine) (PP) was synthesized and used for the preparation of a series of poly(ionic liquid)s (PILs) via the quaternization reaction. These PILs were subsequently loaded with polyoxometalates (POMs) to create innovative catalysts for the oxidation of alkenes. Comprehensive structural analysis of the catalysts showed that these PILs exhibited a high loading amount ratio of up to 542 % for POMs, which were well-dispersed on the surface of PILs. The PILs loaded POMs catalysts, especially for PW-PIL-TB-2PP with H₃PW₁₂O₄₀ as the POMs, displayed remarkable activity and stability in oxidizing cyclooctene, achieving a conversion rate of 97 % and a selectivity of 99 % for 1,2-epoxycyclooctane over six consecutive runs without notable loss. Furthermore, the PW-PIL-TB-2PP catalyst could also be used for the oxidation of a wide range of cyclic, linear, and aromatic alkenes.

我们合成了一种新型季铵化试剂 (1E,1′E)-1,1′-(1,4-亚苯基)双(N-(3-(1H-咪唑-1-基)丙基)甲亚胺) (PP)，并通过季铵化反应将其用于制备一系列聚离子液体 (PIL)。随后，这些聚离子液体负载了聚氧化金属盐（POMs），形成了用于氧化烯烃的创新催化剂。催化剂的全面结构分析表明，这些 PILs 的 POMs 负载率高达 542%，POMs 在 PILs 表面分散良好。负载 PILs 的 POMs 催化剂，尤其是以 H3PW12O40 为 POMs 的 PW-PIL-TB-2PP 催化剂，在氧化环辛烯时表现出显著的活性和稳定性，在连续六次运行中，1,2-环氧环辛烷的转化率达到 97%，选择性达到 99%，且无明显损失。此外，PW-PIL-TB-2PP 催化剂还可用于氧化多种环状、线性和芳香族烯烃。

引用次数: 0