1563-80-0Relevant academic research and scientific papers
Unexpected, Latent Radical Reaction of Methane Propagated by Trifluoromethyl Radicals
Zargari, Nima,Winter, Pierre,Liang, Yong,Lee, Joo Ho,Cooksy, Andrew,Houk,Jung, Kyung Woon
, p. 9820 - 9825 (2016)
Thorough mechanistic studies and DFT calculations revealed a background radical pathway latent in metal-catalyzed oxidation reactions of methane at low temperatures. Use of hydrogen peroxide with TFAA generated a trifluoromethyl radical (?CF3), which in turn reacted with methane gas to selectively yield acetic acid. It was found that the methyl carbon of the product was derived from methane, while the carbonyl carbon was derived from TFAA. Computational studies also support these findings, revealing the reaction cycle to be energetically favorable.
Efficient synthesis of acetic acid via Rh catalyzed methanol hydrocarboxylation with CO2 and H2 under milder conditions
Cui, Meng,Qian, Qingli,Zhang, Jingjing,Chen, Chunjun,Han, Buxing
, p. 3558 - 3565 (2017)
Acetic acid is an important bulk chemical and synthesis of acetic acid via methanol hydrocarboxylation with CO2 and H2 is a very promising route. In this work, we studied the reaction over a number of catalytic systems. It was found that Rh2(CO)4Cl2 with 4-methylimidazole (4-MI) as the ligand was very efficient in the presence of LiCl and LiI. Acetic acid began to form at 150°C. The TOF was as high as 26.2 h-1 and the yield of acetic acid could reach 81.8% at 180°C. The catalytic system had obvious advantages, such as simplicity, high activity and selectivity, milder reaction conditions, and less corrosiveness. The excellent cooperation of CO and Cl- in Rh2(CO)4Cl2, suitable basicity and aromaticity of the ligand 4-MI, and the hydrogen bonding ability of Cl- were crucial for the outstanding performance of the catalytic system. The control experiments showed that the reaction did not proceed via the CO pathway.
Synthesis of acetic acid from CO2, CH3I and H2using a water-soluble electron storage catalyst
Yatabe, Takeshi,Kamitakahara, Kazuki,Higashijima, Kaede,Ando, Tatsuya,Matsumoto, Takahiro,Yoon, Ki-Seok,Enomoto, Takao,Ogo, Seiji
supporting information, p. 4772 - 4774 (2021/05/25)
This paper reports a possible mechanism of acetic acid formation from CO2, CH3I and H2in aqueous media and the central role played by a water-soluble Rh-based electron storage catalyst. In addition to water-solubility, we also report the crystal structures of two presumed intermediates. These findings together reveal (1) the advantage of water, not only as a green solvent, but also as a reactive Lewis base to extract H+from H2, (2) the role of the metal (Rh) centre as a point for storing electrons from H2and (3) the importance of an electron-withdrawing ligand (quaterpyridine, qpy) that supports electron storage.
Carbon Dioxide to Methanol: The Aqueous Catalytic Way at Room Temperature
Sordakis, Katerina,Tsurusaki, Akihiro,Iguchi, Masayuki,Kawanami, Hajime,Himeda, Yuichiro,Laurenczy, Gábor
supporting information, p. 15605 - 15608 (2016/10/25)
Carbon dioxide may constitute a source of chemicals and fuels if efficient and renewable processes are developed that directly utilize it as feedstock. Two of its reduction products are formic acid and methanol, which have also been proposed as liquid organic chemical carriers in sustainable hydrogen storage. Here we report that both the hydrogenation of carbon dioxide to formic acid and the disproportionation of formic acid into methanol can be realized at ambient temperature and in aqueous, acidic solution, with an iridium catalyst. The formic acid yield is maximized in water without additives, while acidification results in complete (98 %) and selective (96 %) formic acid disproportionation into methanol. These promising features in combination with the low reaction temperatures and the absence of organic solvents and additives are relevant for a sustainable hydrogen/methanol economy.
Catalytic conversion of glucose into alkanediols over nickel-based catalysts: A mechanism study
Tan, Zhichao,Miao, Gai,Liu, Chang,Luo, Hu,Bao, Liwei,Kong, Lingzhao,Sun, Yuhan
, p. 62747 - 62753 (2016/07/13)
The conversion of isotope-labeled glucose (d-1-13C-glucose) into alkanediols was carried out in a batch reactor over a Ni-MgO-ZnO catalyst to reveal the C-C cleavage mechanisms. The unique role of the MgO-ZnO support was highlighted by 13C NMR and GC-MS analysis qualitatively and the MgO-ZnO favored isomerization of glucose to fructose. 13C NMR, GC-MS and HPLC analysis demonstrated that the C1 position of ethylene glycol, the C1 and C3 positions of 1,2-propanediol and the C1 position of glycerin were labeled with 13C, which is attributed to a C-C cleavage at d-1-13C-glucose's corresponding positions through retro-aldol condensation. A hydrogenolysis followed by hydrogenation pathway was proposed for glucose converted into alkanediols at 493 K with 6.0 MPa of H2 pressure over Ni based catalysts.
Methane to acetic acid over Cu-exchanged zeolites: Mechanistic insights from a site-specific carbonylation reaction
Narsimhan, Karthik,Michaelis, Vladimir K.,Mathies, Guinevere,Gunther, William R.,Griffin, Robert G.,Romn-Leshkov, Yuriy
supporting information, p. 1825 - 1832 (2015/03/04)
The selective low temperature oxidation of methane is an attractive yet challenging pathway to convert abundant natural gas into value added chemicals. Copper-exchanged ZSM-5 and mordenite (MOR) zeolites have received attention due to their ability to oxidize methane into methanol using molecular oxygen. In this work, the conversion of methane into acetic acid is demonstrated using Cu-MOR by coupling oxidation with carbonylation reactions. The carbonylation reaction, known to occur predominantly in the 8-membered ring (8MR) pockets of MOR, is used as a site-specific probe to gain insight into important mechanistic differences existing between Cu-MOR and Cu-ZSM-5 during methane oxidation. For the tandem reaction sequence, Cu-MOR generated drastically higher amounts of acetic acid when compared to Cu-ZSM-5 (22 vs 4 μmol/g). Preferential titration with sodium showed a direct correlation between the number of acid sites in the 8MR pockets in MOR and acetic acid yield, indicating that methoxy species present in the MOR side pockets undergo carbonylation. Coupled spectroscopic and reactivity measurements were used to identify the genesis of the oxidation sites and to validate the migration of methoxy species from the oxidation site to the carbonylation site. Our results indicate that the CuII-O-CuII sites previously associated with methane oxidation in both Cu-MOR and Cu-ZSM-5 are oxidation active but carbonylation inactive. In turn, combined UV-vis and EPR spectroscopic studies showed that a novel Cu2+ site is formed at Cu/Al 0.2 in MOR. These sites oxidize methane and promote the migration of the product to a Bronsted acid site in the 8MR to undergo carbonylation.
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.
The metabolic and biochemical impact of glucose 6-sulfonate (sulfoquinovose), a dietary sugar, on carbohydrate metabolism
Sacoman, Juliana L.,Badish, Lauren N.,Sharkey, Thomas D.,Hollingsworth, Rawle I.
, p. 21 - 29,9 (2012/12/12)
Increased activity of the main carbohydrate pathways (glycolysis, pentose phosphate, and hexosamine biosynthetic pathways) is one of the hallmarks of metabolic diseases such as cancer. Sulfoquinovosyl diacylglycerol is a sulfoglycolipid found in the human
The metabolic and biochemical impact of glucose 6-sulfonate (sulfoquinovose), a dietary sugar, on carbohydrate metabolism
Sacoman, Juliana L.,Badish, Lauren N.,Sharkey, Thomas D.,Hollingsworth, Rawle I.
, p. 21 - 29 (2013/01/15)
Increased activity of the main carbohydrate pathways (glycolysis, pentose phosphate, and hexosamine biosynthetic pathways) is one of the hallmarks of metabolic diseases such as cancer. Sulfoquinovosyl diacylglycerol is a sulfoglycolipid found in the human
Study of the Beckmann rearrangement of acetophenone oxime over porous solids by means of solid state NMR spectroscopy
Fernandez, Ana Belen,Lezcano-Gonzalez, Ines,Boronat, Mercedes,Blasco, Teresa,Corma, Avelino
experimental part, p. 5134 - 5141 (2011/06/21)
The Beckmann rearrangement of acetophenone oxime using zeolite H-beta and silicalite-N as catalysts has been investigated by means of 15N and 13C solid state NMR spectroscopy in combination with theoretical calculations. The results obtained show that the oxime is N-protonated at room temperature on the acid sites of zeolite H-beta. At reaction temperatures of 423 K or above, the two isomeric amides, acetanilide and N-methyl benzamide (NMB) are formed, and interact with the Bronsted acid sites of zeolite H-beta through hydrogen bonds. The presence of residual water hydrolyzes the two amides, while larger amounts inhibit the formation of NMB and cause the total hydrolysis of the acetanilide. Over siliceous zeolite silicalite-N, containing silanol nests as active sites, the oxime is adsorbed through hydrogen bonds and only acetanilide is formed at reaction temperatures of 423 K or above. In the presence of water, the reaction starts at 473 K, still being very selective up to 573 K, and the amide is partially hydrolyzed only above this temperature. the Owner Societies 2009.
