Catalysts
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2023
·Vol. 13
·期 7
·1038
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IF 3.9
Jincheng Wu,Guoguo Liu,Qin Liu,Yajing Zhang,Fu Ding,Kangjun Wang
The hydrogenation of methyl formate to methanol is considered one of the most effective methods for recycling methyl formate products. We recently developed a highly efficient and cost-effective Cu-SiO2catalyst using the ammonia-evaporation (AE) method. The Cu-SiO2-AE catalyst demonstrated superior performance, achieving a methyl formate conversion of 94.2% and a methanol selectivity of 99.9% in the liquid product. The catalyst also displayed excellent stability over a durability test of 250 h. Compared to the commonly used Cu-Cr catalyst in the industry, the Cu-SiO2-AE catalyst exhibited higher conversion of methyl formate and methanol yield under the same reaction conditions. Characterization results revealed a significant presence of Si-OH groups in the Cu-SiO2-AE catalyst. These groups enhanced the hydrogen spillover effect and improved hydrogenation efficiency by preventing sintering during the reaction to stabilize the Cu species. The strategy employed in this study is applicable to the rational design of highly efficient catalysts for industrial applications.Keywords:Cu-SiO2catalyst;hydrogenation of methyl formate;methanol;catalyst stability
研究领域:
化学工程
·
催化化学
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产品关联
DOI
高影响因子
ChemCatChem
·
2018
·Vol. 11
·期 3
·1123-1130
·
IF 4.674
Xiao-Li Li,Guo-Hui Yang,Meng Zhang,Xiao-Feng Gao,Hong-Juan Xie,Yun-Xing Bai,Ying-Quan Wu,Jun-Xuan Pan,Yi-Sheng Tan
Graphical Tuning selectivity : Cu/SiO 2 was prepared by ammonia evaporation and used as catalyst for the direct synthesis of ethanol from CO hydrogenation. Both the Cu + /(Cu + +Cu 0 ) values and copper crystallite sizes had significant effects on the selectivity towards ethanol. Cu/SiO 2 catalyst was prepared by the ammonia evaporation method for the direct synthesis of ethanol from CO hydrogenation. The catalyst exhibited the initial ethanol selectivity as high as 40.0 wt %, which dramatically decreased from 40.0 to 9.6 wt % on the stream of 50 h. XRD, XPS, TEM and N 2 O titration techniques were employed to elucidate the ethanol selectivity change and catalyst structure evolution during reaction process. The experiment and characterization results indicated that both Cu + /(Cu + +Cu 0 ) value and copper crystallite size had great effects on the ethanol selectivity. During the initial 38 h, the ethanol selectivity obviously decreased from 40.0 to 18.2 wt %, and Cu + /(Cu + +Cu 0 ) value on the catalyst surface rapidly dropped from 0.67 to 0.39, while the copper crystallite size remained almost unchanged. However, during the reaction period of 38–50 h, the Cu + /(Cu + +Cu 0 ) value possessed no distinct change, but a further decrease in ethanol selectivity and a rapid aggregation in Cu particles were observed simultaneously. The present systematic investigation demonstrated that the decrease of Cu + /(Cu + +Cu 0 ) value was the main factor for the loss of ethanol selectivity during the initial 38 h, whereas the rapid growth of Cu particles during the reaction period of 38–50 h were mainly contributed to the further decline of ethanol selectivity.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·Vol. 26
·期 11
·6748-6759
·
IF 9.3
Yitian Zhang,Jie Gao,Chao Jiang,Gang Luo,Jiajun Fan,James H. Clark,Shicheng Zhang
Chemical upgrading as a recycling technology for poly(ethylene terephthalate) (PET) waste plastic is an effective way to help solve the current challenges of plastic pollution. Catalytic methanolysis technology enables the depolymerization of PET into high-value dimethyl terephthalate (DMT) monomers under relatively mild conditions, thereby achieving closed-loop recycling of PET waste plastic. In this study, we compared the catalytic efficiency of Cu/SiO2 catalysts prepared by three different methods for the depolymerization of PET to DMT. Cu/SiO2-IM, prepared through the impregnation method, exhibited the highest activity, with PET conversion and DMT selectivity reaching 92.35% and 99.0%, respectively, at 200 °C without any initial gas pressure. The exceptional performance of Cu/SiO2-IM can be attributed to its small metal particles, substantial specific surface area, a high ratio of Brønsted acid sites (BAS) to Lewis acid sites (LAS) and the balance of Cu+ and Cu0 active sites on the catalytic surface. Furthermore, possible reaction mechanisms of Cu-based catalysts in the catalytic methanolysis of PET were investigated: Cu+ initiates the attack on the carbon groups along the long PET chain and enhances the nucleophilic attack during the depolymerization reaction, while Cu0 readily interacts with the hydroxyl group of methanol, leading to the formation of a new ester group between the oxygen atom in the hydroxyl group of methanol and the carbon atom in the CO group of PET polyester. This low-cost and high-efficiency catalytic methanolysis study provides a practical approach to PET waste plastic recycling.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Jia Hongyan,Lv Qing,Xia Qineng,Hu Wanpeng,Wang Yanqin
Efficient conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to renewable fuels such as 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF) is of significance for sustainable energy supply. For efficient catalyst design, it is important to understand the catalytic behavior and clarify the influence of physico-chemical properties of catalyst on reaction performance. Herein, to study the structure-activity relationships of monometallic Cu catalysts for HMF hydrogenolysis, a series of Cu/SiO2 catalysts with different physico-chemical properties were prepared and compared for their catalytic performance in HMF hydrogenolysis. It was found that Cu/SiO2-HT-8.5 catalyst prepared by hydrothermal method showed excellent activity in HMF hydrohydrolysis reaction. Under the optimal reaction condition, the total yield of liquid fuels reaches 91.6% with 57.1% yield of DMF and 34.5% yield of DMTHF in THF solvent. Characterizations such as XRD, H2-TPR, N2-adsorption/desorption, TEM and XPS revealed that the Cu particles in the Cu/SiO2-HT-8.5 catalyst have uniform size and high dispersion. The Cu species and the SiO2 support have relatively weak interaction and are easy to be reduced to Cu0, which makes it show excellent activity in the hydrogenolysis of HMF.
研究领域:
催化化学
·
可再生资源与能源
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产品关联
DOI
PubMed
高影响因子
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