16651-47-1Relevant academic research and scientific papers
Identification of active surface species for friedel-crafts acylation and koch carbonylation reactions by insitu solid-state NMR spectroscopy
Lezcano-González, Inés,Vidal-Moya, José A.,Boronat, Mercedes,Blasco, Teresa,Corma, Avelino
, p. 5138 - 5141 (2013)
Finding the culprits: Insitu NMR spectroscopy combined with theoretical calculations show the formation of acetyl species covalently bound to framework oxygen atoms in acid zeolites. These species, and not the usually assumed acylium cations, are the reac
Ultrathin WO3·0.33H2O Nanotubes for CO2 Photoreduction to Acetate with High Selectivity
Sun, Songmei,Watanabe, Motonori,Wu, Ji,An, Qi,Ishihara, Tatsumi
, p. 6474 - 6482 (2018)
Artificial photosynthesis from CO2 reduction is severely hampered by the kinetically challenging multi-electron reaction process. Oxygen vacancies (Vo) with abundant localized electrons have great potential to overcome this limitation. However, surface Vo usually have low concentrations and are easily oxidized, causing them to lose their activities. For practical application of CO2 photoreduction, fabricating and enhancing the stability of Vo on semiconductors is indispensable. Here we report the first synthesis of ultrathin WO3·0.33H2O nanotubes with a large amount of exposed surface Vo sites, which can realize excellent and stable CO2 photoreduction to CH3COOH in pure water under solar light. The selectivity for acetum generation is up to 85%, with an average productivity of about 9.4 μmol g-1 h-1. More importantly, Vo in the catalyst are sustainable, and their concentration was not decreased even after 60 h of reaction. Quantum chemical calculations and in situ DRIFT studies revealed that the main reaction pathway might be CO2 → ?COOH → (COOH)2 → CH3COOH.
Hierarchically Porous Metal–Organic Framework/MoS2 Interface for Selective Photocatalytic Conversion of CO2 with H2O into CH3COOH
Yu, Fengyang,Jing, Xu,Wang, Yao,Sun, Mingyang,Duan, Chunying
supporting information, p. 24849 - 24853 (2021/09/20)
Metal–organic frameworks (MOFs) provide a platform to design new heterogeneous catalysts for catalytic CO2 reduction, but selective formation of C2 valuable liquid fuel products remains a challenge. Herein, we propose a strategy to synthesize composites by integrating MoS2 nanosheets into hierarchically porous defective UiO-66 (d-UiO-66) to form Mo-O-Zr bimetallic sites on the interfaces between UiO-66 and MoS2. The active interfaces are favorable for the efficient transfer of photo-generated charge carriers and for promoting the activity, whereas, the synergy of the components at the interfaces achieves selectivity for C2 production. The d-UiO-66/MoS2 composite facilitates the photo-catalytic conversion of gas phase CO2 and H2O to CH3COOH under visible light irradiation without any other adducts. The evolution rate and selectivity of CH3COOH reached 39.0 μmol g?1 h?1 and 94 %, respectively, without any C1 products, suggesting a new approach for the design of highly efficient photocatalysts of CO2 for C2 production. Theoretical calculations demonstrate the charge-polarized Zr-O-Mo aided the C?C coupling process with the largely reduced energy barrier.
Mechanistic insight into the formation of acetic acid from the direct conversion of methane and carbon dioxide on zinc-modified H-ZSM-5 zeolite
Wu, Jian-Feng,Yu, Si-Min,Wang, Wei David,Fan, Yan-Xin,Bai, Shi,Zhang, Chuan-Wei,Gao, Qiang,Huang, Jun,Wang, Wi
supporting information, p. 13567 - 13573 (2013/09/24)
Methane and carbon dioxide are known greenhouse gases, and the conversion of these two C1-building blocks into useful fuels and chemicals is a subject of great importance. By solid-state NMR spectroscopy, we found that methane and carbon dioxide can be co-converted on a zinc-modified H-ZSM-5 zeolite (denoted as Zn/H-ZSM-5) to form acetic acid at a low temperature range of 523-773 K. Solid-state 13C and 1H MAS NMR investigation indicates that the unique nature of the bifunctional Zn/H-ZSM-5 catalyst is responsible for this highly selective transformation. The zinc sites efficiently activate CH4 to form zinc methyl species (-Zn-CH3), the Zn-C bond of which is further subject to the CO2 insertion to produce surface acetate species (-Zn-OOCCH3). Moreover, the Bronsted acid sites play an important role for the final formation of acetic acid by the proton transfer to the surface acetate species. The results disclosed herein may offer the new possibility for the efficient activation and selective transformation of methane at low temperatures through the co-conversion strategy. Also, the mechanistic understanding of this process will help to the rational design of robust catalytic systems for the practical conversion of greenhouse gases into useful chemicals.
