The Experts below are selected from a list of 47292 Experts worldwide ranked by ideXlab platform
John Robertson - One of the best experts on this subject based on the ideXlab platform.
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Growth of ultrahigh density single-walled carbon nanotube forests by improved Catalyst Design
ACS Nano, 2012Co-Authors: Guofang Zhong, Bingan Chen, Martin Fouquet, Alex W. Robertson, Jamie H. Warner, John RobertsonAbstract:We have grown vertically aligned single-walled carbon nanotube forests with an area density of 1.5 × 10(13) cm(-2), the highest yet achieved, by reducing the average diameter of the nanotubes. We use a nanolaminate Fe-Al(2)O(3) Catalyst Design consisting of three layers of Al(2)O(3), Fe, and Al(2)O(3), in which the lower Al(2)O(3) layer is densified by an oxygen plasma treatment to increase its diffusion barrier properties, to allow a thinner Catalyst layer to be used. This high nanotube density is desirable for using carbon nanotubes as interconnects in integrated circuits.
Guofang Zhong - One of the best experts on this subject based on the ideXlab platform.
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Growth of ultrahigh density single-walled carbon nanotube forests by improved Catalyst Design
ACS Nano, 2012Co-Authors: Guofang Zhong, Bingan Chen, Martin Fouquet, Alex W. Robertson, Jamie H. Warner, John RobertsonAbstract:We have grown vertically aligned single-walled carbon nanotube forests with an area density of 1.5 × 10(13) cm(-2), the highest yet achieved, by reducing the average diameter of the nanotubes. We use a nanolaminate Fe-Al(2)O(3) Catalyst Design consisting of three layers of Al(2)O(3), Fe, and Al(2)O(3), in which the lower Al(2)O(3) layer is densified by an oxygen plasma treatment to increase its diffusion barrier properties, to allow a thinner Catalyst layer to be used. This high nanotube density is desirable for using carbon nanotubes as interconnects in integrated circuits.
Javier Pérez-ramírez - One of the best experts on this subject based on the ideXlab platform.
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Catalyst Design for natural-gas upgrading through oxybromination chemistry
Nature Chemistry, 2016Co-Authors: Vladimir Paunović, Guido Zichittella, Maximilian Moser, Amol P. Amrute, Javier Pérez-ramírezAbstract:Natural gas contains large volumes of light alkanes, and its abundant reserves make it an appealing feedstock for value-added chemicals and fuels. However, selectively activating the C–H bonds in these useful hydrocarbons is one of the greatest challenges in catalysis. Here we report an attractive oxybromination method for the one-step functionalization of methane under mild conditions that integrates gas-phase alkane bromination with heterogeneously catalysed HBr oxidation, a step that is usually executed separately. Catalyst-Design strategies to provide optimal synergy between these two processes are discussed. Among many investigated material families, vanadium phosphate (VPO) is identified as the best oxybromination Catalyst, as it provides selectivity for CH_3Br up to 95% and stable operation for over 100 hours on stream. The outstanding performance of VPO is rationalized by its high activity in HBr oxidation and low propensity for methane and bromomethane oxidation. Data on the oxybromination of ethane and propane over VPO suggest that the reaction network for higher alkanes is more complex. Efficiently and selectively activating the C–H bonds within the light alkanes of natural gas is a challenge that must be overcome if we are to make the most of Earth's abundant reserves. An oxybromination method that functionalizes methane under mild conditions has now been developed and vanadium phosphate was identified as the best Catalyst for this reaction.
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Catalyst Design for natural-gas upgrading through oxybromination chemistry.
Nature Chemistry, 2016Co-Authors: Vladimir Paunović, Guido Zichittella, Maximilian Moser, Amol P. Amrute, Javier Pérez-ramírezAbstract:Natural gas contains large volumes of light alkanes, and its abundant reserves make it an appealing feedstock for value-added chemicals and fuels. However, selectively activating the C-H bonds in these useful hydrocarbons is one of the greatest challenges in catalysis. Here we report an attractive oxybromination method for the one-step functionalization of methane under mild conditions that integrates gas-phase alkane bromination with heterogeneously catalysed HBr oxidation, a step that is usually executed separately. Catalyst-Design strategies to provide optimal synergy between these two processes are discussed. Among many investigated material families, vanadium phosphate (VPO) is identified as the best oxybromination Catalyst, as it provides selectivity for CH3Br up to 95% and stable operation for over 100 hours on stream. The outstanding performance of VPO is rationalized by its high activity in HBr oxidation and low propensity for methane and bromomethane oxidation. Data on the oxybromination of ethane and propane over VPO suggest that the reaction network for higher alkanes is more complex.
Martin Fouquet - One of the best experts on this subject based on the ideXlab platform.
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Growth of ultrahigh density single-walled carbon nanotube forests by improved Catalyst Design
ACS Nano, 2012Co-Authors: Guofang Zhong, Bingan Chen, Martin Fouquet, Alex W. Robertson, Jamie H. Warner, John RobertsonAbstract:We have grown vertically aligned single-walled carbon nanotube forests with an area density of 1.5 × 10(13) cm(-2), the highest yet achieved, by reducing the average diameter of the nanotubes. We use a nanolaminate Fe-Al(2)O(3) Catalyst Design consisting of three layers of Al(2)O(3), Fe, and Al(2)O(3), in which the lower Al(2)O(3) layer is densified by an oxygen plasma treatment to increase its diffusion barrier properties, to allow a thinner Catalyst layer to be used. This high nanotube density is desirable for using carbon nanotubes as interconnects in integrated circuits.
Alex W. Robertson - One of the best experts on this subject based on the ideXlab platform.
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Growth of ultrahigh density single-walled carbon nanotube forests by improved Catalyst Design
ACS Nano, 2012Co-Authors: Guofang Zhong, Bingan Chen, Martin Fouquet, Alex W. Robertson, Jamie H. Warner, John RobertsonAbstract:We have grown vertically aligned single-walled carbon nanotube forests with an area density of 1.5 × 10(13) cm(-2), the highest yet achieved, by reducing the average diameter of the nanotubes. We use a nanolaminate Fe-Al(2)O(3) Catalyst Design consisting of three layers of Al(2)O(3), Fe, and Al(2)O(3), in which the lower Al(2)O(3) layer is densified by an oxygen plasma treatment to increase its diffusion barrier properties, to allow a thinner Catalyst layer to be used. This high nanotube density is desirable for using carbon nanotubes as interconnects in integrated circuits.