TY - JOUR
T1 - Evaluation of bimetallic catalysts for the growth of carbon nanotube forests
AU - Tornatzky, Hans
AU - Hardeman, David
AU - Esconjauregui, Santiago
AU - D'Arsié, Lorenzo
AU - Xie, Rongsi
AU - Sugime, Hisashi
AU - Yang, Junwei
AU - Makaryan, Taron
AU - Thomsen, Christian
AU - Robertson, John
PY - 2013/12
Y1 - 2013/12
N2 - We systematically study the growth of carbon nanotube forests by chemical vapor deposition using evaporated monometallic or bimetallic Ni, Co, or Fe films supported on alumina. Our results show two regimes of catalytic activity. When the total thickness of catalyst is larger than nominally 1nm, bimetallic catalysts tend to outperform the equivalent layers of a single metal, yielding taller forests of multi-walled carbon nanotubes (CNTs). In contrast, for layers thinner than ~1nm, bimetallic catalysts are notably less active than individually. However, the amount of small diameter and single-walled CNTs is significantly increased. This possible transition at ~1nm might be related to different catalyst composition after annealing, depending whether or not the films overlap during evaporation and alloy during catalyst formation.
AB - We systematically study the growth of carbon nanotube forests by chemical vapor deposition using evaporated monometallic or bimetallic Ni, Co, or Fe films supported on alumina. Our results show two regimes of catalytic activity. When the total thickness of catalyst is larger than nominally 1nm, bimetallic catalysts tend to outperform the equivalent layers of a single metal, yielding taller forests of multi-walled carbon nanotubes (CNTs). In contrast, for layers thinner than ~1nm, bimetallic catalysts are notably less active than individually. However, the amount of small diameter and single-walled CNTs is significantly increased. This possible transition at ~1nm might be related to different catalyst composition after annealing, depending whether or not the films overlap during evaporation and alloy during catalyst formation.
KW - Bimetallic catalysts
KW - Carbon nanotube forests
KW - Catalytic activity
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U2 - 10.1002/pssb.201300143
DO - 10.1002/pssb.201300143
M3 - Article
AN - SCOPUS:84889102019
VL - 250
SP - 2605
EP - 2610
JO - Physica Status Solidi (B): Basic Research
JF - Physica Status Solidi (B): Basic Research
SN - 0370-1972
IS - 12
ER -