Molecular Catalysis
·
2024
·
IF 3.9
Zuwei Luo,Yun Shen,Di Fang,Chuanchao He,Yueqiang Cao,Wei Li,Yi-An Zhu,Jinghong Zhou,Xinggui Zhou
Support materials play vital roles in heterogenous catalysis via the so-called support effects, and understanding on the support effects is beneficial for the design of high-performance catalysts. Herein, we represent detailed investigations on the support effects of Ag catalysts for dimethyl glycolate (DMO) semi-hydrogenation to methyl glycolate (MG), where G6 silica with amorphous mesopores, SBA-15 with parallel mesopores and silica nanospheres (MSNS) with center-radial ones were employed as the supports. The hydrogenation activity decreases in the order of Ag/MSNS > Ag/SBA-15 > Ag/G6 while the MG selectivity in the order of Ag/G6 > Ag/MSNS > Ag/SBA-15 at the same reaction conditions, indicating remarkable support effects on both activity and selectivity. Structural characterizations, temperature programmed experiments and in-situ FTIR of DMO adsorption experiments demonstrate that the weak confinement effect of G6 leads to the larger sized Ag nanoparticles and weakened activation of DMO and H 2 , which contributes to low hydrogenation activity. In contrast, the ordered mesoporous SBA-15 and MSNS deliver well confinement effects for Ag nanoparticles and the activation of DMO and H 2 , but the distinct pore structures result in different activation and diffusion behaviors. Finally, DMO conversion and MG yield are well correlated with the competitive adsorption of H 2 versus DMO on Ag catalysts, indicating such competitivity as a descriptor for DMO semi-hydrogenation over Ag catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2016
·
IF 2.322
Lu Li,Dezhang Ren,Jun Fu,Yunjie Liu,Fangming Jin,Zhibao Huo
An efficient process for the conversion of dimethyl oxalateinto ethylene glycol with high selectivity and high yield over Cu 2 O was investigated. In situ formed Cu as a true catalytically active species showed a good catalytic performance for DMO conversion to produce EG in 95% yield.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Yannan Sun,Qingxiang Ma,Qingjie Ge,Jian Sun
Oxygenated chemicals are essential to modern industries. However, selective syntheses with controllable products are still challenging over a single heterogeneous catalyst. Herein, a confined iron catalyst is designed for balanced syntheses of ethanol and methyl acetate via dimethyl oxalate (DMO) hydrogenation. With the characteristic structure of a microsphere, the Fe@C catalyst promotes the enrichment of hydrogen to reach a tunable selectivity of ethanol (84.3%) and methyl acetate (77.9%). The highest selectivity of methyl acetate is reached at a H2/DMO molar ratio as low as 20, which is the lowest among catalysts reported for DMO hydrogenation by now. The molecule-level mechanism of DMO hydrogenation is further investigated. It proves that Fe5C2 in Fe@C is the main active center of DMO hydrogenation and Fe3O4 promotes the conversion of the intermediate especially in a low H2/DMO molar ratio. This work provides a strategy for tuning targeted oxygenated chemicals.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhuo Ma,Yihui Li,Zheng Li,Ziyin Liu,Xuepeng Wang,Yuan Tan,Xingkun Chen,Wei Lu,Yunjie Ding
Increasing dimethyl oxalate (DMO) hydrogenation activity remains a challenge. A Cu catalyst was designed by creating Cu nanoparticles (NPs) over SiO 2 layer formed on the CeO 2 particles (SiO 2 @CeO 2 ) using the ammonia evaporation method followed by the calcination and reduction step. The optimized 30Cu/SiO 2 @5CeO 2 catalyst shows good performance in the micro-packed bed reactor (100 % DMO conversion, 95.9 % ethylene glycol (EG) selectivity, 200 h stability) under the condition of the ratio of H 2 to DMO (H 2 /DMO) = 30, 190 °C and 2 MPa in the run, and CeO 2 was proved to be effective in the DMO hydrogenation process. The exposed CeO 2 on the surface of catalyst was found to facilitate the formation of Cu + by its interaction between adjacent Cu nanoparticles, resulting in the faster adsorption and dissociation of C=O bond on the catalyst surface, according to the characterization results obtained by the XRD, XPS and in situ FT-IR, etc.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
HELVETICA CHIMICA ACTA
·
2022
·Vol. 105
·期 6
·e202200017
·
IF 2.201
Geng-Wei Liu,Peng-Bin Pan,Xin Zhang,Yuan-Yuan Huang,Peng Liu,Ye-Yan Qin,Yuan-Gen Yao
Zinc titanate (ZnTiO 3 ) has recently been applied in various areas for its unique properties. Herein, through tuning the phase structures of ZnTiO 3 support, we synthesized two different Pd-based catalysts for CO oxidative coupling to DMO and further investigated their structure-activity relationships for the first time. The results indicated that the strong metal-support interaction between the cubic phase ZnTiO 3 and Pd species leads to an enriched Pd electronic density and promotes the bridged CO adsorption. As a result, the as-synthesized catalyst with cubic phase ZnTiO 3 performed a turnover frequency (TOF) of 339.3 min −1 , which was much higher than the hexagonal one (226.3 min −1 ).
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2020
·Vol. 98
·期 11
·2321-2329
·
IF 1.687
Guojing Ji,Jie Ding,Qin Zhong
This study focused on the performances and kinetics of the transesterification reaction of diethyl oxalate with methanol to prepare ethyl methyl oxalate via microreactor technology. The conversion of 79.8% of diethyl oxalate (DEO) and the selectivity of 65.9% of ethyl methyl oxalate (EMO) was obtained under the following optimized conditions: the mole ratio of methanol to diethyl oxalate was 3.3:1, the temperature was 35°C, the K 2 CO 3 catalyst concentration was 15 mg/mL, and the residence time was 2.30 minutes. In the temperature range of 25°C to 38°C, the simplified dynamic model was found to obtain the reaction order (α = 2.30), frequency factor (k 0 = 2.377 × 10 5 ), and apparent activation energy (E = 31.86 kJ/mol). The macroscopic dynamic equation was derived from the experimental result of the transesterification reaction of two feedstocks, which can be obtained through a series of calculations.
研究领域:
化学工程
·
催化反应
·
有机合成
✓ 已验证
DOI
高影响因子
HELVETICA CHIMICA ACTA
·
2023
·Vol. 106
·期 5
·e202200203
·
IF 1.8
Peng Liu,Xin Zhang,Yuan-Yuan Huang,Geng-Wei Liu,Chen-Jie Li,Pin-Mei Yan,Ye-Yan Qin,Rong Guo,Si-Qi Wu,Yun-Yun Zeng,Peng-Bin Pan,Yuan-Gen Yao
High active Pd-based catalyst with low loading capacity for CO oxidative coupling with methyl nitrite (MN) to dimethyl oxalate (DMO) has aroused great interest in the large-scale production of DMO for the next hydrogenation to bring forth ethylene glycol (EG). Here, spinel composite oxide support, namely MgAl 2 O 4 , had been prepared through three different methods: solid combustion method (MAO-SC), hydrothermal method (MAO-HT) and co-precipitation method (MAO-CP), and further Pd nanoparticles were anchored to the surface of MgAl 2 O 4 through a simple wetness impregnation method. In the CO direct esterification to DMO reaction, the Pd/MAO-SC catalyst, which used MgAl 2 O 4 support prepared by solid combustion method, exhibited the highest intrinsic activity with Turnover frequency (TOF) value of 2.39 s −1 and DMO weight space-time yield (956.8 g⋅kg cat −1 ⋅h −1 ) with 44.1 % CO conversion and 97.8 % DMO selectivity, and showed negligible attenuation of activity during the process of continuous reaction for 100 h. The characterization results confirmed that abundant oxygen defect sites occurred in MAO-SC synthesized by combustion method not only can help to anchor the Pd nanoparticles with appropriate size and dispersion, but also can promote the interfacial electron transfer from MgAl 2 O 4 support to Pd nanoparticles, thus significantly enhancing the metal-support interaction (MSI) and providing more CO bridge-adsorption sites that is favorable for the CO oxidative coupling with MN to DMO reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2025
·
IF 17.7
Yannan Sun,Jiafeng Yu,Xingtao Sun,Yu Han,Qingjie Ge,Jian Sun
Molybdenum carbide has shown great potential in various hydrogenation reactions, and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in the efficient utilization of coal resources. In this study, a molybdenum carbide catalyst with a three-dimensional mesh-like hollow structure and lattice defects was carefully designed. The MoO 3 precursor with abundant oxygen vacancies and defects was prepared by flame spray pyrolysis, and a structural modifier, Cu, was introduced by sputtering. The Cu deposited by sputtering affected the carburization and phase evolution processes. A three-dimensional mesh-like hollow structure composed of defective molybdenum carbide is formed, with the β -Mo 2 C exhibiting lattice distortions and defects. This defective β -Mo 2 C exhibits high reactivity, and facilitates the C=O hydrogenation process, showing a high reactivity of 83.1% yield in the hydrogenation of dimethyl oxalate. This work provides a new approach to the design and application of molybdenum carbide catalysts.
研究领域:
能源化学
·
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yaqi Qu,Yan Wang,Jianwei Li,Qiuxia Xu,Xin Liang,Angran Jiang
CO coupling to dimethyl oxalate (DMO) has been considered as the most important part in industrial production of ethylene glycol (EG). Five kinds of Pd nanoparticles with various morphologies were successfully synthesized by liquid-phase reduction. The exposed crystal planes of these Pd nanoparticles were identified and quantified. The corresponding supported Pd/α-Al 2 O 3 showed excellent catalytic activities for CO coupling reaction and the catalysts including Pd icosahedra can enhanced the selectivity of DMO to 98% and remained unchanged for 50 hours. The characterization results illustrated that the exposure of Pd (111) facets enhanced the intensities of bridged CO, which contributed to the high performance of the Pd-based catalysts. DFT calculations revealed CO adsorbed on Pd (111) facets had higher binding energies. This work systematically discussed the influence of Pd morphologies. Experimental and theoretical results confirmed that the Pd (111) facets showed better catalytic activities for CO coupling reaction.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Jianzhe Shi,Yan He,Kui Ma,Siyang Tang,Changjun Liu,Hairong Yue,Bin Liang
The dimethyl oxalate (DMO) hydrogenation reaction is the key step of indirect synthesis of C 2 -C 4 oxygenates (e.g., ethanol) from syngas. Copper-based catalysts have been extensively explored for DMO hydrogenation. However, the unstable copper active sites induced by metal-particle growth at high rection temperatures (e.g., > 553 K) is an impediment to the stable performance. Herein, we report a facile co-precipitation method to confine Cu active sites in the layered double hydroxide for the hydrogenation of DMO to ethanol. The effects of Mg/Al molar ratio on the catalytic performance were systematically investigated to get insights into the structure-activity relationship. The results indicate that the CuMgAl-LDH-1.25 catalyst possesses regular lamellar structures, highly dispersed Cu active sites, and moderate acidic sites, which synergistically achieves a stable performance with a DMO conversion of ca. 100 % and ethanol selectivity exceeding 83 % at 553 K, 3 MPa.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Huiyu Tian,Haifeng En,Bingwen Li,Jinxian Zhao
An efficient Cu@C/SiO 2 catalyst for the hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG) was prepared by sorbitol-modified ammonia evaporation method followed by calcination in N 2 . The Cu@C/SiO 2 catalyst exhibited the superior catalytic activity and stability for DMO hydrogenation compared with the Cu/SiO 2 catalyst. The optimized Cu@C/SiO 2 –1/4 catalyst exhibited an MG yield of 63 % during 90 h long-term evaluation under temperature of 210 °C, pressure of 1.9 MPa, WHSV of 1.25 g DMO ·g Cu -1 ·h -1 and H 2 /DMO of 150. The characterization results indicated that Cu dispersion can be significantly enhanced by the addition of an appropriate amount of sorbitol and the surface Cu 0 and Cu + species were effectively regulated by the amount of sorbitol. The catalytic activity of Cu@C/SiO 2 was linearly dependent on specific area of Cu + species under the sufficient specific area of Cu° for H 2 dissociation. In addition, the sorbitol–derived carbon species on the catalyst were also favorable for the enhanced stability owing to the suppression of Cu sintering.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yinhe Hai,Tong Guan,Yibin Feng,Ziheng Zhen,Youwei Yang,Ying Hu,Jing Lv,Yue Wang,Xinbin Ma
A promising route for producing biodegradable polyglycolic acid material from syngas has garnered increasing attentions. In this route, one of the pivotal issues is developing favorable catalysts for semi-hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG). Silver catalysts were reported to be effective but suffered from the high cost. Herein, we prepared small-sized Cu@Ag/SiO 2 catalysts with appropriate Ag/Cu ratios by a facile wet impregnation method. This core–shell structure facilitated the intermetallic electronic transference from Cu to Ag. The surface exposure of electron-rich silver species could promote the catalytic activity and MG desorption in the DMO hydrogenation, which achieved high efficiency without compromising the MG selectivity. The optimal catalyst with Ag/Cu mass ratio of 3/2 displayed excellent space time yield towards MG of 47.3 g·g Ag −1 ·h −1 . These insights could offer a potential strategy to reduce the silver-based catalyst cost for the semi-hydrogenation of DMO to MG.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）