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2024年6月嘲风作品集（二）

已有 433 次阅读 2024-8-21 14:39 |个人分类:作品发表|系统分类:论文交流

▲ Vol 58 Issue 23 | 11 June, 2024

Creating Atomically Iridium-Doped PdOx Nanoparticles for Efficient and Durable Methane Abatement

Yingjie Wang, Guangyan Xu, Yanwei Sun, Wei Shi, Xiaoyan Shi, Yunbo Yu, and Hong He

The urgent environmental concern of methane abatement, attributed to its high global warming potential, necessitates the development of methane oxidation catalysts (MOC) with enhanced low-temperature activity and durability. Herein, an iridium-doped PdOx nanoparticle supported on silicalite-1 zeolite (PdIr/S-1) catalyst was synthesized and applied for methane catalytic combustion. Comprehensive characterizations confirmed the atomically dispersed nature of iridium on the surface of PdOx nanoparticles, creating an Ir4f–O–Pdcus microstructure. The atomically doped Ir transferred more electrons to adjacent oxygen atoms, modifying the electronic structure of PdOx and thus enhancing the redox ability of the PdIr/S-1 catalysts. This electronic modulation facilitated methane adsorption on the Pd site of Ir4f–O–Pdcus, reducing the energy barrier for C–H bond cleavage and thereby increasing the reaction rate for methane oxidation. Consequently, the optimized PdIr0.1/S-1 showed outstanding low-temperature activity for methane combustion (T50 = 276 °C) after aging and maintained long-term stability over 100 h under simulated exhaust conditions. Remarkably, the novel PdIr0.1/S-1 catalyst demonstrated significantly enhanced activity even after undergoing harsh hydrothermal aging at 750 °C for 16 h, significantly outperforming the conventional Pd/Al2O3 catalyst. This work provides valuable insights for designing efficient and durable MOC catalysts, addressing the critical issue of methane abatement.

https://pubs.acs.org/doi/10.1021/acs.est.4c00868

▲ Vol 36 Issue 11 | 11 June, 2024

Machine Learning-Driven Discovery and Structure–Activity Relationship Analysis of Conductive Metal–Organic Frameworks

Jinglong Lin, Huibao Zhang, Mojgan Asadi, Kai Zhao, Luming Yang, Yunlong Fan, Jintao Zhu, Qianyi Liu, Lei Sun, Wen Jun Xie, Chenru Duan, Fanyang Mo, and Jin-Hu Dou

Electrically conductive metal–organic frameworks (MOFs) are a class of materials with emergent applications in fields such as electrocatalysis, electrochemical energy storage, and chemiresistive sensors due to their unique combination of porosity and conductivity. However, due to the structural complexity and versatility, rational design of conductive MOFs is still challenging, which limits their further development and applications. To overcome this limitation, we established a database of 224 conductive MOFs, covering all of the reported conductive MOFs as far as we know, and utilized a combination of machine learning (ML) models and density functional theory (DFT) calculations to develop structure–conductivity relationship models. The interpretability of the models provided guidelines for the design of these materials and allowed us to identify new conductive MOFs through rapid screening. Subsequent experiments confirmed the model’s reliability and viability by synthesizing and validating a conductive MOF, CuTTPD, selected via the ML screening. Our results demonstrate that ML models are powerful tools for prescreening new conductive MOFs, thereby accelerating the development of this field.

https://pubs.acs.org/doi/10.1021/acs.chemmater.4c00229

▲ Vol 146 Issue 23 | 12 June, 2024

Nonalternant Nanographenes Containing N-Centered Cyclopenta[ef]heptalene and Aza[7]Helicene Units

Shuhai Qiu, Abel Cárdenas Valdivia, Weiwen Zhuang, Faan-Fung Hung, Chi-Ming Che, Juan Casado, and Junzhi Liu

Introducing helical subunits into negatively curved π-systems has a significant effect on both the molecular geometry and photophysical properties; however, the synthesis of these helical π-systems embedded with nonbenzenoid subunits remains challenging due to the high strain deriving from both the curvature and helix. Here, we report a family of nonalternant nanographenes containing a nitrogen (N)-doped cyclopenta[ef]heptalene unit. Among them, CPH-2 and CPH-3 can be viewed as hybrids of benzoannulated cyclopenta[ef]heptalene and aza[7]helicene. The crystal structures revealed a saddle geometry for CPH-1, a saddle-helix hybrid for CPH-2, and a twist-helix hybrid for CPH-3. Experimental measurements and theoretical calculations indicate that the saddle moieties in CPHs undergo flexible conformational changes at room temperature, while the aza[7]helicene subunit exhibits a dramatically increased racemization energy barrier (78.2 kcal mol–1 for CPH-2, 143.2 kcal mol–1 for CPH-3). The combination of the nitrogen lone electron pairs of the N-doped cyclopenta[ef]heptalene unit with the twisted helix fragments results in rich photophysics with distinctive fluorescence and phosphorescence in CPH-1 and CPH-2 and the similar energy fluorescence and phosphorescence in CPH-3. Both enantiopure CPH-2 and CPH-3 display distinct circular dichroism (CD) signals in the UV–vis range. Notably, compared to the reported fully π-extended helical nanographenes, CPH-3 exhibits excellent chiroptical properties with a |gabs| value of 1.0 × 10–2 and a |glum| value of 7.0 × 10–3; these values are among the highest for helical nanographenes.

https://pubs.acs.org/doi/10.1021/jacs.4c03815

▲ Vol 124 Issue 11 | 12 June, 2024

Spatially Confined Microcells: A Path toward TMD Catalyst Design

Shasha Guo, Mingyu Ma, Yuqing Wang, Jinbo Wang, Yubin Jiang, Ruihuan Duan, Zhendong Lei, Shuangyin Wang, Yongmin He, and Zheng Liu

With the ability to maximize the exposure of nearly all active sites to reactions, two-dimensional transition metal dichalcogenide (TMD) has become a fascinating new class of materials for electrocatalysis. Recently, electrochemical microcells have been developed, and their unique spatial-confined capability enables understanding of catalytic behaviors at a single material level, significantly promoting this field. This Review provides an overview of the recent progress in microcell-based TMD electrocatalyst studies. We first introduced the structural characteristics of TMD materials and discussed their site engineering strategies for electrocatalysis. Later, we comprehensively described two distinct types of microcells: the window-confined on-chip electrochemical microcell (OCEM) and the droplet-confined scanning electrochemical cell microscopy (SECCM). Their setups, working principles, and instrumentation were elucidated in detail, respectively. Furthermore, we summarized recent advances of OCEM and SECCM obtained in TMD catalysts, such as active site identification and imaging, site monitoring, modulation of charge injection and transport, and electrostatic field gating. Finally, we discussed the current challenges and provided personal perspectives on electrochemical microcell research.

https://pubs.acs.org/doi/10.1021/acs.chemrev.3c00711

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