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2016-03-05 zsh 研之成理

1. 包信和院士课题组的又一篇Science新鲜出炉了。感觉每次包院士都是直接用催化结果征服了Science ,膜拜中!

本文研究内容:合成气选择性制备烯烃(超高选择性,震撼)

研究思路:互补双中心偶联(CO,H2活化和C-C偶联)

催化剂:ZnCrOx/MSAPO


Abstract: Although considerable progress has been made in direct synthesis gas (syngas) conversion to light olefins (C2=-C4=) via Fischer-Tropsch synthesis (FTS), the wide product distribution remains a challenge, with a theoretical limit of only 58% for C2– Chydrocarbons. We present a process that reaches C2=-C4selectivity as high as 80% and C2– C4 94% at carbon monoxide (CO) conversion of 17%. This is enabled by a bifunctional catalyst affording two types of active sites with complementary properties. The partially reduced oxide surface (ZnCrOx) activates CO and H2, and C−C coupling is subsequently manipulated within the confined acidic pores of zeolites. No obvious deactivation is observed within 110 hours. Furthermore, this composite catalyst and the process may allow use of coal- and biomass-derived syngas with a low H2/CO ratio.



相关评论文章:http://news.sciencenet.cn/htmlnews/2016/3/339727.shtm

思考点:为什么包院士会选取ZnCrOx,这是一种怎样的催化剂设计以及筛选的思路?




2. 本文出自厦门大学郑南峰课题组,可以当作早前Nature Materials (doi:10.1038/nmat4555)的姊妹篇,虽然是完全不一样的体系,但是核心思想是一致的:即表面配体对金属纳米催化的促进作用


Abstract: Metal nanoclusters whose surface ligands are removable while keeping their metal framework structures intact are an ideal system for investigating the influence of surface ligands on catalysis of metal nanoparticles. We report in this work an intermetallic nanocluster containing 62 metal atoms, Au34Ag28(PhC≡C)34 and its use as a model catalyst to explore the importance of surface ligands inpromoting catalysis. As revealed by single-crystal diffraction, the 62 metalatoms in the cluster are arranged as a four-concentric-shell Ag@Au17@Ag27@Au17structure. All phenylalkynyl(PA) ligands are linearly coordinated to the surface Au atoms with staple “PhC≡C-Au-C≡CPh” motif. Compared with reported thiolated metal nanoclusters,the surface PA ligands on Au34Ag28(PhC≡C)34 are readily removed at relatively low temperatures while the metal core remainsintact. The clusters before and after removal of surface ligands are used ascatalysts for the hydrolytic oxidation of organosilanes to silanols. It is, forthe first time, demonstrated that the organic-capped metal nanoclusters work as active catalysts much better than those with surface ligands partially or completely removed.




3. 尺寸可控的单分散CuOx纳米颗粒的合成以及催化反应过程中的尺寸效应,出自西班牙巴伦西亚理工大Avelino Corma 课题组。

催化反应:端炔偶联(好吧,我承认这是我选取这篇文章的目的之一。请原谅我孤陋寡闻,对这类反应没什么认识,趁此机会学习下)


Abstract: We show a facile method to prepare surface-clean monodispersed small and stable CuOx nanoparticles with controllable average sizes from below 1 nm up to ∼5 nm without using bulk capping agent. Structural and surface characterizations show that the chemical states of CuOx nanoparticles and their interactions with O2 are dependent on the particle size. To show their relevance to catalysis, the well-defined monodispersed CuOx nanoparticles have been used for oxidative coupling of alkynes. While the generally used CuCl catalysts presents a reaction induction period and agglomerate into CuOx nanoparticles during the reaction, the induction period disappears when monodispersed CuOx nanoparticles (∼2 nm) were used ascatalyst. Supported CuOnanoparticles on TiO2 behave in the same way as monodispersed CuOx nanoparticles. Kinetic, spectroscopic,and isotopic studies show that Oactivation is the rate-controlling step and that the nature of the oxygen species formed on supported CuOx nanoparticles is dependent on the size of CuOx and determine the catalytic properties for oxidative coupling ofalkynes.



友情提示:请记住大牛Avelino Corma的名字,后期我会将他的研究工作进行总结,分享给大家



4. 按惯例分享J. Catal.一篇,本次选取的是哥伦比亚大学陈经广老师的工作。主要关注点:1) 以CO2为软氧化剂进行乙烷的氧化脱氢; 2)双金属催化剂对乙烷分子不同的活化方式(C-C活化 vs. C-H活化);3) DFT计算对反应机理以及对催化剂设计的启示。


Abstract: An efficient mitigation of abundantly available CO2 is critical for sustainable environmental impact as well as for novel industrial applications. Using ethane, CO2 can be catalytically converted into a useful feedstock (synthesis gas) and a value-added monomer (ethylene) via the dry reforming pathway through the C–C bond scission and the oxidative dehydrogenation pathway through the C–H bond scission, respectively. Results from the current flow-reactor study show that the precious metal bimetallic CoPt/CeO2 catalyst undergoes the reforming reaction to produce syngas with enhanced activity and stability compared to the parent monometallic catalysts. In order to replace Pt, the activities of non-precious CoMo/CeO2 and NiMo/CeO2 are investigated and the results indicate that NiMo/CeO2 is nearly as active as CoPt/CeO2 for the reforming pathway. Furthermore, FeNi/CeO2 is identified as a promising catalyst forthe oxidative dehydrogenation to produce ethylene. Density functional theory (DFT) calculations are performed to further understand the different pathways of the CoPt/CeO2 and FeNi/CeO2 catalysts.





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