当前位置: X-MOL 学术Catal. Today › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Selective dehydration of glycerol on copper based catalysts
Catalysis Today ( IF 5.2 ) Pub Date : 2020-10-12 , DOI: 10.1016/j.cattod.2020.09.031
R.J. Chimentão , P. Hirunsit , C.S. Torres , M. Borges Ordoño , A. Urakawa , J.L.G. Fierro , D. Ruiz

Glycerol is produced in large quantities as a byproduct of biodiesel, and among others hydroxyacetone (acetol) is an important commodity obtained from glycerol. Metallic Cu has been identified as active site for the dehydration of glycerol to hydroxyacetone and acid and metal sites are known to influence the catalytic performance.

In this study, dehydration of glycerol over 5 wt.% copper supported on γ-Al2O3, ZrO2 and SiO2 was investigated. Catalysts were characterized by N2 physisorption, H2-TPR, NH3-TPD, N2O chemisorption, XPS, XRD, FTIR of pyridine adsorption. Cu/ZrO2 exhibited the highest hydroxyacetone yield at 20 % of glycerol conversion and the highest apparent reaction rate. The superior activity of Cu/ZrO2 was attributed to the highly acidic, both Lewis and Brönsted acidic, nature of the support and positive roles of the interfacial sites. The Weisz-Prater (WP) criterion was applied to confirm the absence of intraparticle diffusion limitations. It was assumed spherical particles and first order reaction. The WP value obtained in the worst scenario was less than 0.3 ensuring no diffusion limitation.

Complementary DFT study indicates that both glycerol and hydroxyacetone interact significantly stronger on Cu/γ-Al2O3 and Cu/ZrO2 compared to metallic Cu, suggesting that the active sites are at the interface of Cu particles and the acidic support.



中文翻译:

铜基催化剂上甘油的选择性脱水

甘油是作为生物柴油的副产物而大量生产的,其中,羟丙酮(丙酮醇)是从甘油获得的重要商品。金属铜已被确定为甘油脱水为羟丙酮的活性位点,并且已知酸和金属位点会影响催化性能。

在这项研究中,甘油的脱水超过5重量%的铜负载在γ-Al系2 ö 3,的ZrO 2和SiO 2进行了研究。催化剂的特征在于N 2物理吸附,H 2 -TPR,NH 3 -TPD,N 2 O化学吸附,XPS,XRD,吡啶的FTIR。Cu / ZrO 2在甘油转化率为20%时表现出最高的羟丙酮收率和最高的表观反应速率。Cu / ZrO 2的优异活性归因于路易斯和布朗斯台德都是强酸性的,界面的支撑和积极作用的性质。应用Weisz-Prater(WP)标准来确认不存在粒子内扩散限制。假定为球形颗粒和一级反应。在最坏的情况下获得的WP值小于0.3,确保没有扩散限制。

DFT互补的研究表明,这两种甘油和羟基丙酮的相互作用更强显著的Cu /γ-Al系2 ö 3和Cu /的ZrO 2相比金属的Cu,表明活性位点是在Cu粒子的界面和酸性载体。

更新日期:2020-10-13
down
wechat
bug