756456-88-9Relevant articles and documents
Tuning the Lewis acidity of ZrO2for efficient conversion of CH4and CO2into acetic acid
Li, Yufeng,Liu, Bing,Liu, Jie,Wang, Ting,Shen, Yu,Zheng, Ke,Jiang, Feng,Xu, Yuebing,Liu, Xiaohao
, p. 8978 - 8985 (2021/06/02)
The conversion of CH4 and CO2 into acetic acid is a dream reaction, but it remains a great challenge owing to the inertness of both CH4 and CO2. The formation of acetic acid requires efficient activation of CH4 and CO2. In this work, we demonstrated that enhanced acetic acid production from CH4 and CO2 is achieved via improving the Lewis acidity of ZrO2-containing catalysts. Definitely, the best catalyst (SZ-3) exhibits about 14 times higher activity for acetic acid formation than that of pure ZrO2, owing to its strongest Lewis acidity that facilitates the activation of both CH4 and CO2. The mechanism of acetic acid formation is revealed via DFT calculations. CH4 is activated at Lewis acid sites to form Zr-CH3 and O-H species, and subsequently, the O-H species could readily hydrogenate CO3 species formed from CO2 activation at Lewis acid sites to give HCO3, followed by facile coupling with Zr-CH3 yielding acetic acid with a lower energy barrier.
Transfer hydrogenation of furfural to furfuryl alcohol over modified Zr-based catalysts using primary alcohols as H-donors
Wang, Yantao,Zhao, Deyang,Liang, Rui,Triantafyllidis, Konstantinos S.,Yang, Weiran,Len, Christophe
, (2020/12/07)
Catalytic transfer hydrogenation is gaining increasing attention as a promising alternative to conventional hydrogenation with H2. In present work, a series of modified Zr-based catalysts were synthesized and tested for furfural catalytic transfer hydrogenation into furfuryl alcohol (FA). The results indicated that more than 13 % of furfural conversion and furfuryl alcohol yield could be achieved with modified zirconium hydroxide (mZrH) at 140 °C when compared with zirconium hydroxide (ZrH) using ethanol as H-donor and solvent in continuous flow regime, and the activity could be further enhanced by increasing the reaction temperature or Ru loading on the catalyst. The best result of 92 % furfural conversion with ～99 % FA selectivity was obtained at 150 °C with 6% Ru/mZrH as catalyst, and the productivity of FA is 5.5 mmol g?1 h?1 which is 2 times higher than that reported with ZrH in batch. Moreover, long-term stability study of the catalysts indicated that 6% Ru/mZrH not only performs a better activity, but also a better stability than 6% Ru/ZrH. Characterizations of the catalysts by BET, XRD, EA, IR, SEM-EDS, XPS and CO2 adsorption indicated that zirconium hydroxide (ZrH) was successfully modified with hydroxylamine, leading to significantly change of its morphology and basic sites. And the deactivation of the catalysts was due to both the leaching of Ru and the deposition of side-products on its surface.
Catalytic transfer hydrogenation of furfural to furfuryl alcohol using easy-to-separate core-shell magnetic zirconium hydroxide
Hou, Pan,Ma, Mingwei,Zhang, Peng,Cao, Jingjie,Liu, Hui,Xu, Xingliang,Yue, Huijuan,Tian, Ge,Feng, Shouhua
, p. 2715 - 2722 (2021/02/16)
A hollow core-shell magnetic zirconium hydroxide catalyst was synthesized and employed for the catalytic transfer hydrogenation (CTH) ofnumerous biomass-derived platform molecules (furfural and other carbonyl compounds). 93.9% conversion of furfural and 97.3% selectivity of furfuryl alcohol was achieved under mild reaction conditions (160 °C, 4 h, 0.1 g catalyst) with 2-propanol as the H-donor. After 7 times of reaction cycles, the catalyst retained excellent conversion (91.1%) and selectivity (97.8%) and no structural damage was found. Furthermore, a scale-up experiment was carried out, and the results proved that the catalyst has a prospect for industrial applications in the CTH reaction.
Fluorite-like hydrolyzed hexanuclear coordination clusters of Zr(IV) and Hf(IV) with syn-syn bridging N,N,N-trimethylglycine in soft crystal structures exhibiting cold-crystallization
Matsuoka, Moe,Takao, Koichiro,Tsushima, Satoru
, (2021/09/27)
Tetravalent metal ions are hydrolyzed under presence of N,N,N-trimethylglycine hydrochloride (betaine hydrochloride, [Hbet]Cl) in aqueous solutions to afford [M6(μ3-O)4(μ3-OH)4(μ-bet)8(κ-bet)4(H2O)4]12+ (M4+ = Zr4+ (1), Hf4+ (2)) as hydrated perchlorate salts. These compounds were characterized by single crystal X-ray diffraction, elemental analysis and IR spectroscopy. As a result, we have found that fluorite-like [M6O8] coordination clusters are formed through octahedral arrangement of six M4+ linked by μ3-O atoms. Additionally, each pair of neighboring M4+ are connected by the μ-bet ligand through a syn-syn bridging coordination of its carboxylate moiety. This interaction seems to prevent further growth of the fluorite structure leading to formation of MO2. It was difficult to directly distinguish each μ3-O atom to be μ3-OH? or μ3-O2? due to its strongly anisotropic thermal displacement in the obtained structures. Bond valence sum analysis suggested that four μ3-OH? and four μ3-O2? are alternately arranged in the [M6O8] core motifs. Indeed, such a symmetric structure of [M6(μ3-O)4(μ3-OH)4] was confirmed in another phase of 1 at 296 K, where 1 transforms to a monoclinic structure (1′). The number of ClO4? counteranions found in the structure determination is not enough to compensate + 12 charge of [M6(μ3-O)4(μ3-OH)4(μ-bet)8(κ-bet)4(H2O)4]12+ in any unit cells of 1, 1′ and 2. Instead, large solvent/ion accessible voids have been actually observed in their crystal structures, indicating that the missing ClO4? are located therein and are significantly disordered to make them invisible in the crystallography. DSC analysis revealed that ClO4? and H2O/H3O+ in the crystal lattice of 1 undergo unique structure relaxation and rearrangements pronounced by cold-crystallization to induce the phase transition from 1 to 1′ with elevating temperature.
Metal-reinforced sulfonic-acid-modified zirconia for the removal of trace olefins from aromatics
Kong, Decun,Peng, Qian,Shi, Li,Wang, Xin,Meng, Xuan,Hu, Xiude,Liu, Naiwang
, p. 1644 - 1653 (2020/04/28)
Metal-reinforced sulfonic-acid-modified zirconia catalysts were successfully prepared and used to remove trace olefins from aromatics in a fixed-bed reactor. Catalysts were characterized by ICP-OES, N2 adsorption–desorption, X-ray diffraction, thermogravimetric analysis (TGA), and pyridine-FTIR spectroscopy. Different metals and calcination temperatures had great influence on the catalytic activity. Alumina-reinforced sulfated zirconia exhibited outstanding catalytic performance, stable regeneration activity, and giant surface area, and are promising in industrial catalysis. TGA showed that the decomposition of methyl could be attributed to Br?nsted acid sites, and pyridine-FTIR spectroscopy proved the weak Br?nsted sites on these synthesized metal-reinforced sulfated zirconia. Also, a relation between the reaction rate and weak Br?nsted acid density is proposed.
Cu/Ni-doped sulfated zirconium oxide immobilized on CdFe2O4 NPs: a cheap, sustainable and magnetically recyclable inorgano-catalyst for the efficient preparation of α-aminonitriles in aqueous media
Nasseri, Mohammad Ali,Ramezani-Moghadam, Simin,Kazemnejadi, Milad,Allahresani, Ali
, p. 4233 - 4256 (2020/07/08)
Abstract: A new multifunctional bimetallic nanocatalyst was prepared by immobilization of Cu/Ni-doped sulfated zirconium oxide on magnetic cadmium ferrite (CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni) and used as an efficient recyclable catalyst for one-pot as well as stepwise preparation of α-aminonitriles under mild conditions. The magnetic nanocatalyst was characterized by FTIR, TGA, VSM, XRD, EDX, FE-SEM, and TEM analyses. Also, the surface acidity of the catalyst was measured by pyridine adsorption assay. The catalyst possesses various active sites which could catalyst a variety of aromatic and aliphatic aldehydes to the corresponding α-amionitriles under moderate to high yields in the presence of aniline. Furthermore, transformation of ketones to the desired α-amionitriles and some bis-aminonitriles was also performed by this method. The catalyst could be readily recovered from the reaction mixture and reused for several times without significant loss of activity. Graphic abstract: A general and efficient method has been developed for transformation of a variety of aliphatic, aromatic aldehydes and ketones to the corresponding α-aminonitriles using a multifunctional recyclable CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni nanocatalyst.[Figure not available: see fulltext.]
The selective reductive amination of aliphatic aldehydes and cycloaliphatic ketones with tetragonal zirconium dioxide as the heterogeneous catalyst
Bai, Peng,Li, Jiacong,Tong, Xinli,Wang, Shun,Zhang, Haigang,Zhang, Ming
, (2020/07/17)
A selective reductive amination of aliphatic aldehydes and cycloaliphatic ketones is achieved with tetragonal zirconium dioxide (t-ZrO2) as the catalyst. With N, N-dimethyl formamide (DMF) as the solvent, low-molecular-weight amine source and reductant, a more than 99 percent yield of N, N-dimethylpentan-1-amine or N, N-dimethyl cyclohexanamine was obtained when n-pentanal or cyclohexanone was used as the substrate. Particularly, the crystallographic structures exhibit a significant effect on catalytic performance where the tetragonal crystalline was preferable to monoclinic one during the reductive amination reaction. In addition, the recycling experiments of catalysts indicate that t-ZrO2 still kept a high catalytic activity even after being reused five times. From the result of DFT calculations, it is concluded that the crystalline of zirconium dioxide is closely related to the charge transferring rate between the catalyst and the adsorbed reactant. Finally, based on the experiment phenomena and simulation result, a possible reaction mechanism is proposed for the reductive amination of cyclohexanone.
Effect of zirconia polymorph on the synthesis of diphenyl carbonate over supported lead catalysts
Wang, Songlin,Niu, Hongying,Guo, Mengjun,Wang, Jianji,Chen, Tong,Wang, Gongying
, p. 117 - 124 (2019/03/05)
Zirconia supported Pb-based catalysts with purely tetragonal/monoclinic crystals were prepared and analyzed well by XRD, TEM-EDS, XPS, H2-TPR, BET, Py-IR and NH3-TPD techniques. The results indicate that zirconia polymorph has great effect on their structure and catalytic property for the synthesis of diphenyl carbonate (DPC) through methyl phenyl carbonate (MPC) disproportionation due to the differences of surface chemical properties, and tetragonal zirconia supported lead catalyst (TZ-Pb) shows bigger dispersion degree of PbO, higher surface area and Lewis acid amounts and thereby exhibits higher catalytic activity and selectivity compared to monoclinic zirconia supported catalyst (MZ-Pb). Furthermore, TZ-Pb shows better reusability due to strong metal-support interaction and may be readily recycled for at least four times without remarkable reactivity loss. This work provides a prospective reference for the facile and efficient synthesis of zirconia polymorph materials in various catalysis applications.
Preparation and catalytic property of Pb-Zr mixed oxides for methyl phenyl carbonate disproportionation to synthesize diphenyl carbonate
Wang, Songlin,Niu, Hongying,Wang, Jianji,Chen, Tong,Wang, Gongying
, p. 18 - 25 (2018/11/10)
Pb-Zr mixed oxides with 15.2 wt% PbO loading were prepared by four different preparation processes, and their catalytic performances for the disproportionation of methyl phenyl carbonate (MPC) to synthesize diphenyl carbonate (DPC) were evaluated. Physicochemical characterizations including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), BET surface area measurement, H2-temperature programmed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD) and infrared spectroscopy of pyridine adsorption (Py-IR), as well as catalytic tests of MPC disproportionation reaction showed that catalyst preparation process exerted significant influence on the composition, structural property, catalytic performance of obtained catalysts, and the catalyst prepared by co-precipitation method (PbZr-CP) demonstrated better dispersion of active phase, larger specific surface area and more Lewis acid sites on the surface due to the strong interaction of Pb and Zr, and thus exhibited higher catalytic activity than those prepared by other processes.
Esterification of Tertiary Amides by Alcohols Through C?N Bond Cleavage over CeO2
Toyao, Takashi,Nurnobi Rashed, Md.,Morita, Yoshitsugu,Kamachi, Takashi,Hakim Siddiki,Ali, Md. A.,Touchy,Kon, Kenichi,Maeno, Zen,Yoshizawa, Kazunari,Shimizu, Ken-ichi
, p. 449 - 456 (2018/09/11)
CeO2 has been found to promote ester forming alcoholysis reactions of tertiary amides. The present catalytic system is operationally simple, recyclable, and it does not require additives. The esterification process displays a wide substrate scope (>45 examples; up to 93 % isolated yield). Results of a density functional theory (DFT) study combined with in situ FT-IR observations indicate that the process proceeds through rate limiting addition of a CeO2 lattice oxygen to the carbonyl group of the adsorbed acetamide species with energy barrier of 17.0 kcal/mol. This value matches well with experimental value (17.9 kcal/mol) obtained from analysis of the Arrhenius plot. Further studies by in situ FT-IR and temperature programmed desorption using probe molecules demonstrate that both acidic and basic properties are important, and consequently, CeO2 showed the best performance for the C?N bond cleavage reaction.
