Hydrogenation of diethyl oxalate over Cu/SiO2 catalyst with enhanced activity and stability: Contribution of the spatial restriction by varied pores of support

Applied Catalysis B: Environmental

Popa

Tang

et al. 2017

Dimethyl Oxalate (DMO) hydrogenation for ethylene glycol (EG) production is problematic due to environmental concerns and safety regulations. Therefore, development of improved methods for diethyl oxalate (DEO) hydrogenation based EG production is desirable. The objective of this research was to develop a cost-effective © 2017. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ 2 and environmentally benign approach for the synthesis of highly active and stable Cu/SiO 2 catalysts for selective hydrogenation of diethyl oxalate (DEO) to ethylene glycol (EG). Here, ammonium carbonate is used to prepare Cu/SiO 2 catalysts through deposition precipitation instead of the conventional pollution-producing evaporation process associated with the use of ammonia. The Cu/SiO 2 catalysts prepared with the new method achieved 6.9-13.1% higher selectivity and showed better stability. The improved stability and selectivity resulted from increased chemical adsorption of DEO and H 2 due to the high Cu 2 O concertation and Cu + /(Cu 0 +Cu + ) ratio (reduced from ion-exchanged Cu-O-Si units), and reduced carbon deposition on the Cu/SiO 2 catalyst. The Cu 2 O reduced from Cu-O-Si units in the Cu/SiO 2 catalyst prepared bythe new method was more stable than the Cu + species reduced from copper phyllosilicate in the Cu/SiO 2 catalyst prepared by the conventional method. Therefore, the new Cu/SiO 2 catalyst preparation method appears most promising.

Section: Catalyst Preparationsmentioning

confidence: 99%

Section: Physiochemical Properties Of Catalystsmentioning

confidence: 99%

Section: Bet Surface Areamentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

See 3 more Smart Citations

Highly selective and stable Cu/SiO2 catalysts prepared with a green method for hydrogenation of diethyl oxalate into ethylene glycol

Applied Catalysis B: Environmental

Popa

Tang

et al. 2017

Effect of cu content on Ce‐doping CuO/ZrO₂ catalysts for low‐temperature hydrogenation of dimethyl oxalate to ethanol

Asia-Pacific J Chem Eng

Wang

Liu

et al. 2021

Self Cite

In order to solve the Cu sintering in dimethyl oxalate (DMO) hydrogenation to ethanol, the reaction temperature should be kept at a low value, however, which is unable to show excellent catalytic performance. Herein, the reaction temperature decreased significantly from above 260 to 220°C over Ce‐doping Cu/ZrO2 catalyst, which retained high catalytic efficiency with little influence on the catalyst structure after 96 h on stream. Besides, the structure and performance were changed greatly by adjusting the Cu content. For example, the ethanol selectivity can reach 96.1% based on the 100% conversion of DMO over Ce‐doping Cu/ZrO2 catalysts with 40% content of Cu. Based on systematic characterization, the catalyst possessed higher exposed Cu surface area along with the proper amount of medium acidic sites, avoiding the strong ones that could bring about a series of by‐products. As a result, the formed synergistic effects between Cu sites and medium acidic sites provided the active sites with high efficiency for ethanol synthesis.

Comparative study on CuO–La₂O₃/ZrO₂ catalysts prepared by amino acid complexing‐combustion in CO₂ hydrogenation

Asia-Pacific J Chem Eng

Zhang

et al. 2023

Self Cite

For preparation of functional materials, the facile and efficient complexing‐combustion method has many advantages such as the easily operating, no washing and filtration process, a slight loss of the products obtained, material saving, and so on. Here, CuO–La2O3/ZrO2 catalysts were prepared by using various amino acids as complexing‐combustion agents for CO2 hydrogenation to methanol. Based on the results of characterization by N2 physical adsorption, SEM, XRD, XPS, and chemisorption, along with the experimental data, it was found that the structure and catalytic activity of as‐obtained catalysts depended on the group type and carbon chain length of amino acids. Among them, L‐glutamic acid had two carboxyl hydrophilic groups and a moderately long carbon chain, which was conducive to the formation of a larger specific surface area along with abundant pores and a smaller grain size of CuO. Moreover, the prepared catalyst showed a higher Cu dispersion and the abundant surface acidic/basic sites. As a result, the larger Cu+/Cu0 surface area contributed to the active adsorption of H2 and CO2 molecules, which greatly improved the hydrogenation of CO2, while the methanol production increased with the increase of surface basicity/acidity. For example, the selectivity to methanol of 87.9%, which corresponded to a methanol yield of 120 mg/(h gcatalyst), was obtained along with a stable online performance (life span more than 144 h) at 2.2 MPa, 220°C, H2/CO2 = 2, and GHSV = 3000 h−1.