96-35-5Relevant articles and documents
Highly efficient mesostructured Ag/SBA-15 catalysts for the chemoselective synthesis of methyl glycolate by dimethyl oxalate hydrogenation
Zheng, Jianwei,Lin, Haiqiang,Zheng, Xinlei,Duan, Xinping,Yuan, Youzhu
, p. 129 - 133 (2013)
Ag/SBA-15 catalyst is found to exhibit excellent catalytic activity and long-term stability for the chemoselective hydrogenation of dimethyl oxalate to methyl glycolate. The size of Ag crystallites, which is markedly affected by the Ag loading levels and catalyst pretreatment conditions, is a key factor determining the reaction rate of the structure-sensitive hydrogenation but hardly influenced the product distribution. The best catalytic hydrogenation activity is obtained over the Ag/SBA-15 catalyst with an average Ag crystallite size of around 3.9 nm.
Oxidative esterification of ethylene glycol in methanol to form methyl glycolate over supported Au catalysts
Ke, Yi-Hu,Qin, Xiao-Xia,Liu, Chun-Ling,Yang, Rong-Zhen,Dong, Wen-Sheng
, p. 3141 - 3150 (2014)
Au/ZnO and Au/Al2O3 catalysts with various mean Au particle diameters (2.0-7.4 nm) were prepared by the deposition of pre-formed Au colloids. These catalysts were evaluated in the oxidative esterification of ethylene glycol to methyl glycolate. The results show that the catalytic activity per surface Au atom is independent of Au particle diameter in the range of 3-7.4 nm, whereas smaller Au particles (~2.0 nm) show an inferior activity. This behavior was observed on both Au/ZnO and Au/Al2O3 catalysts. This observed correlation between activity and Au particle diameter confirms the assertion that only exposed atoms are catalytically active. We prepared gold nanoparticles with a uniform mean diameter of ~3 nm loaded on various supports, i.e. ZnO, Al2O3, SiO2, TiO2 and CeO2. Among these five catalysts, Au/ZnO gave the best catalytic activity in the reaction followed by Au/Al2O 3. Au/SiO2, Au/TiO2 and Au/CeO2 gave significantly lower activities. The variation in catalytic behavior of these gold catalysts on different supports originates from differences in the anchoring of the supported Au particles, the gold oxidation state, the gold-support interaction, and the acidity of the support. the Partner Organisations 2014.
Three dimensional Ag/KCC-1 catalyst with a hierarchical fibrous framework for the hydrogenation of dimethyl oxalate
Ouyang, Mengyao,Wang, Yue,Zhang, Jian,Zhao, Yujun,Wang, Shengping,Ma, Xinbin
, p. 12788 - 12791 (2016)
The novel fibrous nano-silica (KCC-1) based silver nanocatalyst exhibits excellent catalytic activity with a high TOF value (53.2 h-1) in the gas-phase hydrogenation of DMO to MG. Compared with the traditional mesoporous silica materials, KCC-1 remarkably enhances the accessibility of the silver active sites due to its three dimensional hierarchical channel structure.
Influence of La-doping on the CuO/ZrO2catalysts with different Cu contents for hydrogenation of dimethyl oxalate to ethylene glycol
Ding, Jian,Guo, Xiaohui,Liu, Huimin,Wang, Meihui,Wang, Yaxiong,Wang, Zhenfeng,Yu, Gewen
, p. 18102 - 18113 (2021/10/12)
Herein, Cu/ZrO2catalysts containing different Cu contents with or without La-doping were used for the selective hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG). Effects of La addition and the optimal Cu content were thoroughly investigated. It was found that the Cu0/Cu+pairs located at interfacial sites for CuO/ZrO2catalysts with different Cu contents played an important role in the hydrogenation of DMO to EG. Interestingly, the La-doping could make the copper dispersion increase obviously. Besides, it greatly inhibited the crystal phase transformation from tetragonal to monoclinic zirconia regardless of being calcined at 750 °C. Meanwhile, the incorporation of La promoted the activation of hydrogen although resulting in a small increase in acidic/basic sites over the catalyst surface, which led to a higher conversion of DMO while the selectivity of EG decreased slightly. As a result, 97.2% selectivity of EG, which corresponds to 100% conversion of DMO, was achieved over the La-doped CuO/ZrO2catalyst with 33 wt% Cu content, which was also stable for more than 168 h on stream. This results revealed that the strong interaction between La promoters and Cu species was another type of important active site with high catalytic efficiency in addition to the Cu0/Cu+site of La-doped CuO/ZrO2?catalyst.
Conversion of sugars to methyl lactate with exfoliated layered stannosilicate UZAR-S4
Murillo, Beatriz,de la Iglesia, óscar,Rubio, César,Coronas, Joaquín,Téllez, Carlos
, p. 90 - 96 (2020/04/27)
Biomass has been shown as an alternative to fossil fuels for obtaining chemicals. In this work, the transformation of sugars into methyl lactate (ML) at 160 °C was carried out using the layered stannosilicate UZAR-S3 (University of Zaragoza-solid number 3) and the delaminated material UZAR-S4 (University of Zaragoza-solid number 4) obtained from its exfoliation. The exfoliation of UZAR-S3 to UZAR-S4 increased the accessibility of the compounds to the catalytic sites and the medium-strength acidity. Thus, the yield to ML for sucrose transformation increased from 8% for UZAR-S3 to 49.9 % for UZAR-S4. In the reusability tests, the UZAR-S4 catalyst was characterized before and after reaction by several techniques such as X-ray diffraction, thermogravimetry analysis, scanning electronic microscopy, energy dispersive X-ray spectroscopy and nitrogen adsorption. A deactivation of the catalyst was observed, which was related to carbonaceous deposits that decreased the specific surface area and the pore volume of the catalyst.