PMID- 20973587
OWN - NLM
STAT- MEDLINE
DCOM- 20110207
LR  - 20131121
IS  - 1520-5827 (Electronic)
IS  - 0743-7463 (Linking)
VI  - 26
IP  - 21
DP  - 2010 Nov 2
TI  - Understanding the effect of cobalt particle size on Fischer-Tropsch synthesis: 
      surface species and mechanistic studies by SSITKA and kinetic isotope effect.
PG  - 16558-67
LID - 10.1021/la101555u [doi]
AB  - Co/gamma-Al(2)O(3) catalysts with particle sizes in the range of 4-15 nm were 
      investigated by isothermal hydrogenation (IH), temperature programmed 
      hydrogenation (TPH), and steady-state isotopic transient kinetic analysis 
      (SSITKA). Kinetic isotope effect experiments were used to probe possible 
      mechanisms on Co/gamma-Al(2)O(3) with different particle size. It was found that CO 
      dissociated on Co/gamma-Al(2)O(3) catalysts at 210  degrees C. The total amount of CO(2) 
      formed following the dissociation depends on the cobalt crystal size. O-Co 
      binding energy was found to be highly dependent on the Co metal particle size, 
      whereas similar C-Co binding energy was found on catalysts with different Co 
      particle size. Very strongly bonded carbon and oxygen surface species increased 
      with decreasing particle size and acted as site blocking species in the 
      methanation reaction. SSITKA experiments showed that the intrinsic activity 
      (1/tau(CH(x))) remained constant as the particle size increased from 4 to 15 nm. 
      The number of surface intermediates (N(CH(x))) increased with increasing particle 
      size. The apparent activation energies were found similar for these catalysts, 
      about 85 kJ/mol. D(2)-H(2) switches further confirmed that the particle size did 
      not change the kinetically relevant steps in the reaction. The reactivity of the 
      active sites on the 4 nm particles was the same as those on the 8, 11, and 15 nm 
      particles, and only the number of total available surface active sites was less 
      on the 4 nm particles than on the others.
FAU - Yang, Jia
AU  - Yang J
AD  - Department of Chemical Engineering, Norwegian University of Science & Technology, 
      NO-7491 Trondheim, Norway.
FAU - Tveten, Erik Z
AU  - Tveten EZ
FAU - Chen, De
AU  - Chen D
FAU - Holmen, Anders
AU  - Holmen A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Langmuir
JT  - Langmuir : the ACS journal of surfaces and colloids
JID - 9882736
RN  - 142M471B3J (Carbon Dioxide)
RN  - 3G0H8C9362 (Cobalt)
RN  - 7U1EE4V452 (Carbon Monoxide)
RN  - 7YNJ3PO35Z (Hydrogen)
RN  - AR09D82C7G (Deuterium)
RN  - LMI26O6933 (Aluminum Oxide)
SB  - IM
MH  - Aluminum Oxide/chemistry
MH  - Carbon Dioxide/chemical synthesis/chemistry
MH  - Carbon Monoxide/chemistry
MH  - Catalysis
MH  - Cobalt/*chemistry
MH  - Deuterium/*chemistry
MH  - Hydrogen/*chemistry
MH  - Kinetics
MH  - Oxidation-Reduction
MH  - Particle Size
MH  - Surface Properties
EDAT- 2010/10/27 06:00
MHDA- 2011/02/08 06:00
CRDT- 2010/10/27 06:00
PHST- 2010/10/27 06:00 [entrez]
PHST- 2010/10/27 06:00 [pubmed]
PHST- 2011/02/08 06:00 [medline]
AID - 10.1021/la101555u [doi]
PST - ppublish
SO  - Langmuir. 2010 Nov 2;26(21):16558-67. doi: 10.1021/la101555u.