Polyyne Chain Growth and Ring Collapse Drives Ni-Catalyzed SWNT Growth: A QM/MD Investigation

2010 ◽  
Vol 114 (18) ◽  
pp. 8206-8211 ◽  
Author(s):  
Alister J. Page ◽  
Stephan Irle ◽  
Keiji Morokuma
Keyword(s):  
Chain Growth ◽  
Swnt Growth

Carbon Chain Growth by Sequential Reactions of CO and CO2 with a Transition Metal Carbonyl Complex

2018 ◽  
Author(s):  
Richard Kong ◽  
Mark Crimmin
Keyword(s):  
Transition Metal ◽  
Metal Carbonyl ◽  
Carbon Chain ◽  
Chain Growth ◽  
Carbonyl Complex ◽  
Fischer Tropsch ◽  
Carbon Chains ◽  
Sequential Coupling ◽  
Energy Economy ◽  
Sequential Reactions

<i>The formation of carbon chains by the coupling of COx (X = 1 or 2) units on transition metals is a fundamental step relevant to Fischer-Tropsch catalysis. Fischer-Tropsch catalysis produces energy dense liquid hydrocarbons from synthesis gas (CO and H2) and has been a mainstay of the energy economy since its discovery nearly a century ago. Despite detailed studies aimed at elucidating the steps of catalysis, experimental evidence for chain growth (Cn to Cn+1 ; n > 2) from the reaction of CO with metal complexes is unprecedented. In this paper, we show that carbon chains can be grown from sequential reactions of CO or CO2 with a transition metal carbonyl complex. By exploiting the cooperative effect of transition and main group metals, we document the first example of chain propagation from sequential coupling of CO units (C1 to C3 to C4), along with the first example of incorporation of CO2 into the growing carbon chain.</i><br>

Polymer Chemistry

2004 ◽  
Keyword(s):  
Conducting Polymers ◽  
Liquid Crystalline ◽  
Polymer Chemistry ◽  
Chain Growth ◽  
Crystalline Polymers ◽  
Wide Range ◽  
Cyclic Oligomers ◽  
Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

scholarly journals Synergistic Effect of Alkali Na and K Promoter on Fe-Co-Cu-Al Catalysts for CO2 Hydrogenation to Light Hydrocarbons

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 735
Author(s):  
Yuhao Zheng ◽  
Chenghua Xu ◽  
Xia Zhang ◽  
Qiong Wu ◽  
Jie Liu
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Intermediate Formation ◽  
Active Phase ◽  
Dissociative Adsorption ◽  
Co2 Hydrogenation ◽  
Chain Growth ◽  
Co2 Conversion ◽  
Light Hydrocarbons ◽  
Active Centers

Alkali metal K- and/or Na-promoted FeCoCuAl catalysts were synthesized by precipitation and impregnation, and their physicochemical and catalytic performance for CO2 hydrogenation to light hydrocarbons was also investigated in the present work. The results indicate that Na and/or K introduction leads to the formation of active phase metallic Fe and Fe-Co crystals in the order Na < K < K-Na. The simultaneous introduction of Na and K causes a synergistic effect on increasing the basicity and electron-rich property, promoting the formation of active sites Fe@Cu and Fe-Co@Cu with Cu0 as a crystal core. These effects are advantageous to H2 dissociative adsorption and CO2 activation, giving a high CO2 conversion with hydrogenation. Moreover, electron-rich Fe@Cu (110) and Fe-Co@Cu (200) provide active centers for further H2 dissociative adsorption and O-C-Fe intermediate formation after adsorption of CO produced by RWGS. It is beneficial for carbon chain growth in C2+ hydrocarbons, including olefins and alkanes. FeCoCuAl simultaneously modified by K-Na exhibits the highest CO2 conversion and C2+ selectivity of 52.87 mol% and 89.70 mol%, respectively.

Synthesis of well-defined poly(p-benzamide) from chain-growth polycondensation and its application to block copolymers

2003 ◽  
Vol 199 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Tsutomu Yokozawa ◽  
Miyuki Ogawa ◽  
Atsushi Sekino ◽  
Ryuji Sugi ◽  
Akihiro Yokoyama
Keyword(s):  
Block Copolymers ◽  
Chain Growth

scholarly journals Identification of C2–C5 products from CO2 hydrogenation over PdZn/TiO2–ZSM-5 hybrid catalysts

2021 ◽  
Author(s):  
Jonathan Ruiz Esquius ◽  
Hasliza Bahruji ◽  
Michael Bowker ◽  
Graham J. Hutchings
Keyword(s):  
High Temperature ◽  
Co2 Hydrogenation ◽  
Chain Growth ◽  
Hybrid Catalysts

PdZn/TiO2 combined with ZSM-5 zeolites allowed for consecutive CO2 hydrogenation to CH3OH, CH3OH dehydration to DME, and MTH/DMTH in a one-pass single bed reactor. PdZn alloys, although stable at high temperature, hydrogenate olefins, limiting MTH/DMTH chain growth.

Carbon chain growth reaction of synthesis of lower olefins from syngas on Fe-Co catalyst

2020 ◽  
Vol 504 ◽  
pp. 144211
Author(s):  
Yingzhe Yu ◽  
Jie Zhang ◽  
Hao Lei ◽  
Minhua Zhang
Keyword(s):  
Carbon Chain ◽  
Chain Growth ◽  
Co Catalyst ◽  
Lower Olefins ◽  
Growth Reaction
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