Boron Modified Bifunctional Cu/SiO2 Catalysts with Enhanced Metal Dispersion and Surface Acid Sites for Selective Hydrogenation of Dimethyl Oxalate to Ethylene Glycol and Ethanol

Boron (B) promoter modified Cu/SiO2 bifunctional catalysts were synthesized by sol-gel method and used to produce ethylene glycol (EG) and ethanol (EtOH) through efficient hydrogenation of dimethyl oxalate (DMO). Experimental results showed that boron promoter could significantly improve the catalytic performance by improving the structural characteristics of the Cu/SiO2 catalysts. The optimized 2B-Cu/SiO2 catalyst exhibited excellent low temperature catalytic activity and long-term stability, maintaining the average EG selectivity (Sel.EG) of 95% at 190 °C, and maintaining the average EtOH selectivity (Sel.EtOH) of 88% at 260 °C, with no decrease even after reaction of 150 h, respectively. Characterization results revealed that doping with boron promoter could significantly increase the copper dispersion, enhance the metal-support interaction, maintain suitable Cu+/(Cu+ + Cu0) ratio, and diminish metallic copper particles during the hydrogenation of DMO. Thus, this work introduced a bifunctional boron promoter, which could not only improve the copper dispersion, reduce the formation of bulk copper oxide, but also properly enhance the acidity of the sample surface, so that the Cu/SiO2 sample could exhibit superior EG selectivity at low temperature, as well as improving the EtOH selectivity at high temperature.

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Effect of Copper Nanoparticles Dispersion on Catalytic Performance of Cu/SiO2Catalyst for Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

Journal of Nanomaterials ◽

10.1155/2013/629375 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Yajing Zhang ◽

Na Zheng ◽

Kangjun Wang ◽

Sujuan Zhang ◽

Jing Wu

Keyword(s):

Ethylene Glycol ◽

Copper Nanoparticles ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Catalytic Performance ◽

Bet Surface Area ◽

X Ray ◽

Dimethyl Oxalate ◽

Effect Of Copper ◽

Average Size

Cu/SiO2catalysts, for the synthesis of ethylene glycol (EG) from hydrogenation of dimethyl oxalate (DMO), were prepared by ammonia-evaporation and sol-gel methods, respectively. The structure, size of copper nanoparticles, copper dispersion, and the surface chemical states were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) and N2adsorption. It is found the structures and catalytic performances of the catalysts were highly affected by the preparation method. The catalyst prepared by sol-gel method had smaller average size of copper nanoparticles (about 3-4 nm), better copper dispersion, higher Cu+/C0ratio and larger BET surface area, and higher DMO conversion and EG selectivity under the optimized reaction conditions.

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Enhanced metal-support interaction between Pd and hierarchical Nb2O5 via oxygen defects induction to promote CO oxidative coupling to dimethyl oxalate

Nanoscale ◽

10.1039/d1nr03370k ◽

2021 ◽

Author(s):

Hong-Zi Tan ◽

Yu-Ping Xu ◽

Siteng Rong ◽

Rongrong Zhao ◽

Hongyou Cui ◽

...

Keyword(s):

Ethylene Glycol ◽

Oxidative Coupling ◽

Dimethyl Oxalate ◽

Support Interaction ◽

Oxygen Defects ◽

Metal Support Interaction ◽

Metal Support

Production of ethylene glycol from coal is a particularly interesting route as it is an economic alternative of the petrochemical-based route. In this process, effectively generating dimethyl oxalate (DMO) is...

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Effect of the calcination temperature of cerium–zirconium mixed oxides on the structure and catalytic performance of WO3/CeZrO2 monolithic catalyst for selective catalytic reduction of NOx with NH3

RSC Advances ◽

10.1039/c7ra03054a ◽

2017 ◽

Vol 7 (39) ◽

pp. 24177-24187 ◽

Cited By ~ 15

Author(s):

Haidi Xu ◽

Mengmeng Sun ◽

Shuang Liu ◽

Yuanshan Li ◽

Jianli Wang ◽

...

Keyword(s):

Low Temperature ◽

Selective Catalytic Reduction ◽

Lewis Acid ◽

Mixed Oxides ◽

Catalytic Reduction ◽

Catalytic Performance ◽

Acid Sites ◽

Lewis Acid Sites ◽

Reduction Of Nox ◽

Calcined Temperature

The calcined temperature of the carrier obviously affected SCR activity of catalysts, WO3/Ce0.68Zr0.32O2-500 showed the best low-temperature NH3-SCR activity due to its more Lewis acid sites and stronger redox property.

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The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH3-SCR Activity of Magnetic Iron-Based Catalyst

Catalysts ◽

10.3390/catal10030314 ◽

2020 ◽

Vol 10 (3) ◽

pp. 314

Author(s):

Xing Ning ◽

Zhi-bo Xiong ◽

Bin Yang ◽

Wei Lu ◽

Shui-mu Wu

Keyword(s):

Nitric Acid ◽

Citric Acid ◽

Sol Gel ◽

Nox Reduction ◽

Combustion Process ◽

Catalytic Performance ◽

Metal Nitrate ◽

Acid Sites ◽

Complexing Agent ◽

Nh3 Scr

Sol-gel spread self-combustion is the burning of the complexing agent in dried gel and the oxidant. Meanwhile, high temperature takes place during the combustion process, which is harmful to the pore structure of the catalyst. The nitrate from metal nitrate precursors as an oxidant could participate in the spread of the self-combustion process. Therefore, the influence of nitrate from metal nitrate on the spread self-combustion of an iron–cerium–tungsten citric acid gel and its catalytic performance of NOx reduction were investigated by removing nitrate via the dissolution of washing co-precipitation with citric acid and re-introducing nitric acid into the former solution. It was found that the removal of nitrate contributes to enhancing the NH3–SCR activity of the magnetic mixed oxide catalyst. The NOx reduction efficiency was close to 100% for Fe85Ce10W5–CP–CA at 250 °C while the highest was only 80% for the others. The results of thermal analysis demonstrate that the spread self-combustion process of citric acid dried gel is enhanced by re-introducing nitric acid into the citric acid dissolved solution when compared with the removal of nitrate. In addition, the removal of nitrate helps in the formation of γ-Fe2O3 crystallite in the catalyst, refining the particle size of the catalyst and increasing its pore volume. The removal of nitrate also contributes to the formation of Lewis acid sites and Brønsted acid sites on the surface of the catalyst compared with the re-introduction of nitric acid. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrates that both Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms exist over Fe85Ce10W5–CP–CA at 250 °C with E–R as its main mechanism.

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Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by Perchlorated Zirconia (HClO4/ZrO2) nanoparticles as a novel solid acid catalyst

Nanoscience and Nanotechnology ◽

10.18063/nn.v0i0.449 ◽

2018 ◽

Vol 2 (2) ◽

Author(s):

Seyed Yousef Mosavian

Keyword(s):

Solid Acid ◽

Condensation Reaction ◽

Solid Acid Catalyst ◽

Sol Gel ◽

Acid Catalyst ◽

Catalytic Performance ◽

Acid Sites ◽

Zro2 Nanoparticles ◽

Calcination Temperatures ◽

Aldehydes And Ketones

Zirconia was synthesized in nanosize by sol-gel method and perchlorated zirconia (HClO4/ZrO2) with various calcination temperatures were prepared and characterized by XRD, FTIR and SEM techniques. The catalyst acidity characters, including the acidicstrength and the total number of acid sites were determined by potentiometric titration. The catalytic performance experiments show that the HClO4/ZrO2 with calcination temperature of 300 °C has the best catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones wereprepared in good to excellent yields via condensation reaction of oaminobenzamide and various types of aldehydes and ketones in the presence of HClO4/ZrO2 nanoparticles as an efficient solid acid catalyst. The catalyst is reusable with moderate loss in activity.

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Remarkable crystal phase effect of Cu/TiO2catalysts on the selective hydrogenation of dimethyl oxalate

RSC Advances ◽

10.1039/c5ra00053j ◽

2015 ◽

Vol 5 (37) ◽

pp. 29040-29047 ◽

Cited By ~ 9

Author(s):

Bin Wang ◽

Chao Wen ◽

Yuanyuan Cui ◽

Xi Chen ◽

Yu Dong ◽

...

Keyword(s):

Catalytic Hydrogenation ◽

Selective Hydrogenation ◽

Catalytic Performance ◽

Crystal Phase ◽

Phase Effect ◽

Dimethyl Oxalate ◽

Support Interaction ◽

Metal Support Interaction ◽

Metal Support ◽

Titania Support

Crystal phase of titania support plays an important role in catalytic hydrogenation of dimethyl oxalate. Optimized catalytic performance was achieved for the Cu/P25 due to the intimate metal support interaction.

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