A5101705250- Zeolite Catalysis and Synthesis
- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- Catalysis and Hydrodesulfurization Studies
- Mesoporous Materials and Catalysis
- Catalysts for Methane Reforming
- Metal-Organic Frameworks: Synthesis and Applications
- Catalysis for Biomass Conversion
- Electrocatalysts for Energy Conversion
- Machine Learning in Materials Science
- Advanced NMR Techniques and Applications
- X-ray Diffraction in Crystallography
- Nanomaterials for catalytic reactions
- Luminescence and Fluorescent Materials
- Chemical Synthesis and Characterization
- Conducting polymers and applications
- Crystallization and Solubility Studies
- Ammonia Synthesis and Nitrogen Reduction
- Asymmetric Hydrogenation and Catalysis
- Muscle activation and electromyography studies
- Advanced Chemical Physics Studies
- Organic Light-Emitting Diodes Research
- Synthesis and Properties of Aromatic Compounds
- Oxidative Organic Chemistry Reactions
- Organic Electronics and Photovoltaics
Sinopec (China)
2016-2025
Shanghai Research Institute of Chemical Industry
2016-2024
Stanford University
2014-2015
SLAC National Accelerator Laboratory
2014-2015
SAIC-GM (China)
2014
Interface (United States)
2014
Jilin University
2012
Fudan University
2006-2010
Wayne State University
1991-1994
A series of new cationic iridium(III) complexes [Ir(piq)2(N∧N)]+PF6- (1−6) (piq =1-phenyl-isoquinoline) containing N∧N ligands with different conjugated lengths were synthesized, where the six bipyridine, phenanthroline, 2-pyridyl-quinoline, 2,2'-biquinoline, 1,1'-biisoquinoline, and 2-(2-quniolinyl)quinoxaline. Single-crystal X-ray diffraction spectra three studied, centers found to adopt a distorted octahedral coordination geometry cis metalated carbons trans nitrogen atoms. UV−vis,...
Little is known on the early stages of methanol-to-olefin (MTO) conversion over H-SAPO-34, before steady-state with highly active polymethylbenzenium cations as most important intermediates reached. In this work, formation and evolution carbenium ions during MTO a H-SAPO-34 model catalyst were clarified via 1H MAS NMR 13C NMR. Several initial species (i.e., three-ring compounds, dienes, polymethylcyclopentenyl, polymethylcyclohexenyl cations) were, for first time, directly verified...
Abstract Direct synthesis of light olefins from syngas (STO) using a bifunctional catalyst composed oxide and zeolite has attracted extensive attention in both academia industry. It is highly desirable to develop robust catalysts that could enhance the CO conversion while simultaneously maintain high selectivity C2-C4 olefins. Herein, we report consisting ZnCr binary (ZnCrO x ) low-Si AlPO-18 zeolite, showing satisfying 45.0% (86.7%, 2 free) olefin/paraffin ratio 29.9 at 25.2% under mild...
The selective hydrogenation of alkynes to alkenes is an important type organic transformation with large-scale industrial applications. This requires efficient catalysts precise selectivity control, and palladium-based metallic are currently employed. Here we show that four-coordinated cationic nickel(II) confined in zeolite can efficiently catalyze the acetylene ethylene, a key process for trace removal prior polymerization process. Under optimized conditions, 100% conversion ethylene up...
Abstract Understanding the atomic-scale structural dynamics of phase transformations is crucial for developing materials and tailoring their properties. However, many are obtained as polycrystalline powders with large unit cells and/or complex structures, making it challenging to investigate detailed changes using conventional X-ray diffraction techniques. Here we employ time-resolved three-dimensional electron reveal topotactic reactions that convert extra-large-pore silicate zeolite...
Abstract The direct synthesis of light olefins from syngas over a bifunctional catalyst containing an oxide and zeolite has been proven to be promising strategy. Nevertheless, unclear reaction network hinders any further enhancement in catalytic performance, such as increasing the conversion CO. We herein report novel composed InZr binary SAPO‐34 displaying superior CO (27.7 %) with selectivity (73.6 at 400 °C, 2.0 MPa. demonstrate that Zr‐doped body‐centered cubic In 2 O 3 phase, exhibiting...
Recent work has reported the discovery of metal surface catalysts by employing a descriptor-based approach, establishing correlation between few well-defined properties material and its catalytic activity. This theoretical aims for similar approach in solid acid catalysis, focusing on reaction propene methanol catalyzed Brønsted acidic zeotype catalysts. Experimentally, ammonia heat adsorption is often used as measure strength sites. Using periodic DFT calculations, we show that this can be...
Ga-modified nano H-ZSM-5 zeolites with different Ga contents were prepared and applied as methanol-to-aromatics (MTA) catalysts. The introduction can strongly increase the selectivity to aromatics but also decrease catalyst lifetime simultaneously. Upon cofeeding of n-butanol methanol, a significant prolongation from 18 ca. 50 h be achieved. According several spectroscopic results, e.g., TGA, GC–MS, in situ UV/vis, solid-state MAS NMR spectroscopy, addition during MTA conversion shows no...
Both aromatic-based and olefin-based cycles involve similar sequences of elementary steps. Energetic span model analysis indicates olefins are active hydrocarbon pool species in H-SAPO-34 H-SSZ-13 for MTO conversion.
We report a heterogeneous catalysis strategy to the sustainable hydration of epoxides by designing robust Lewis acid catalysts confined in zeolite cages as natural shape-selective nanoreactors. In case ethylene oxide hydration, Sn-H-SSZ-13 exhibits remarkable catalytic performance, with an conversion above 99% and monoethylene glycol selectivity 99%, at approaching stoichiometric water/ethylene ratios near-ambient reaction temperatures. It is revealed theoretical studies that partially...
The formation of the initial carbon–carbon (C–C) bonds in methanol-to-hydrocarbon (MTH) conversion on acidic zeolite has been hotly debated for decades. Recently, surface-bound acetyl groups involving C–C during period MTH disclosed. Understanding exact bond-containing intermediates triggering and critical roadmap is essential further development this important reaction. Herein, acetaldehyde from hydrogenation species was identified to be responsible H-ZSM-5 zeolite. By combining kinetic...
Direct propylene epoxidation with molecular oxygen is a dream reaction 100% atom economy, but aerobic challenging because of the undesired over-oxidation and isomerization epoxide products. Herein, we report construction uniform cobalt ions confined in faujasite zeolite, namely, Co@Y, which exhibits unprecedented catalytic performance propylene. Propylene conversion 24.6% achieved at oxide selectivity 57% 773 K, giving state-of-the-art production rate 4.7 mmol/gcat/h. The Co@Y very stable,...
Zeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a effect are challenging to define. Here we introduce descriptor that accounts for the performances H-ZSM-5 zeolite C4 olefin cracking. A series zeolites with similar sheet-like different c-axis lengths were synthesized. We found activity stability improved samples longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy molecular dynamics...
For its unique position in the coal chemical industry, methanol to olefin (MTO) reaction has been a hot topic zeolite catalysis. Due complexities of catalyst structure and networks, many questions such as how chain is built from remain elusive. On basis periodic density functional theory calculations, this work establishes first complete catalytic cycle for MTO via hexamethylbenzene (HMB) trapped HSAPO-34 based on so-called side hydrocarbon pool mechanism. The starts methylation HMB that...
The catalytic performance of Au/oxide catalysts can vary significantly upon the change oxide species or under different catalyst preparation conditions. Due to its complex nature, physical origin this phenomenon remains largely unknown. By extensive density functional theory calculations on a model system, CO oxidation Au/ZrO2, work demonstrates that reaction is very sensitive structure. surface structure variation due transformation phase creation structural defects (e.g., steps) greatly...
We recently proposed the ammonia heat of adsorption as a reactivity descriptor in solid acid catalysis, using it to predict activity zeotype catalysts propene–methanol reaction (J. Phys. Chem. Lett. 2014, 5, 1516–1521). Here we extend approach series alkene reactants, establishing transition state energy scaling relations for ethene and butenes. Using these connection with microkinetic modeling, change pathway function acid-site size. The results illustrate potential descriptor-based model...
Electron-rich (donor) and electron-deficient (acceptor) units to construct donor–acceptor (D–A) conjugated macrocycles were investigated elucidate their interactions with fullerene. Triphenylamine 4,7-bisthienyl-2,1,3-benzothiadiazole alternately linked through acetylene, as the donor acceptor units, respectively, for pentagonal 3B2A hexagonal 4B2A macrocycles. As detected by scanning tunneling microscopy, both D–A found form an interesting concentration-controlled nanoporous monolayer on...
Experimental evidence for the presence of tert-butyl cations, which are important intermediates in acid-catalyzed heterogeneous reactions, on solid acids has still not been provided to date. By combining density functional theory (DFT) calculations with (1)H/(13)C magic-angle-spinning NMR spectroscopy, cation was successfully identified zeolite H-ZSM-5 upon conversion isobutene by capturing this intermediate ammonia.
The origin of the species: first principles method reveals and activity a heterogeneous Au monomer in catalysis selective 1,3-butadiene hydrogenation. active species is an AuI complex, produced from AuIII situ by reduction, stabilized ZrO2 defects. high catalytic selectivity comes stable, but flexible, structure center, which dissociates H2 heterolytically.
A series of square-planar Pt(II) complexes [Pt(C^N)(O^O)] (1–5) (C^N = 2-phenylpyridine, O^O denotes a β-diketonate ligands) is reported. Detailed studies theoretical calculations, electrochemical and photophysical properties have shown that their excited states can be attributed to the mixing 3MLCT, 3LLCT 3LC/3ILCT transitions. For 1, state dominated by C^N ligand. The 2–5, however, are ligands. Through variation ligands, emission colors 1–5 tuned from blue-green yellow. Further...