Structures and Phase Transitions in Physisorption: Molecular-Axis Orientational Ordering in Nitrogen and Carbon Monoxide Monolayers on Graphite

1986 ◽  
Vol 90 (3) ◽  
pp. 211-217 ◽  
Author(s):  
Samuel C. Fain
Keyword(s):  
Carbon Monoxide ◽  
Phase Transitions ◽  
Molecular Axis ◽  
Orientational Ordering

Orientational ordering in C70. Evidence for three distinct phase transitions

1994 ◽  
Vol 220 (3-5) ◽  
pp. 203-206 ◽  
Author(s):  
Sheela K. Ramasesha ◽  
A.K. Singh ◽  
Ram Seshadri ◽  
A.K. Sood ◽  
C.N.R. Rao
Keyword(s):  
Phase Transitions ◽  
Orientational Ordering

EFFECTS OF FINITE REACTION RATES ON THE KINETIC PHASE TRANSITIONS IN THE CATALYTIC OXIDATION OF CARBON MONOXIDE

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1735-1739
Author(s):  
L. D. LÓPEZ-CARREÑO
Keyword(s):  
Carbon Monoxide ◽  
Phase Transitions ◽  
Steady State ◽  
Catalytic Oxidation ◽  
Active Sites ◽  
Nearest Neighbor ◽  
Reaction Rates ◽  
Neighbor Site ◽  
State Configuration ◽  
Oxidation Of Carbon Monoxide

Oxidation of carbon monoxide is one of the most extensively studied heterogeneous catalysis reactions, being important among other applications in automobile-emission control. Catalytic oxidation of carbon monoxide on platinum (111) surface was simulated by the Monte Carlo technique following an extended version of the model proposed by Ziff, Gulari and Barshad (ZGB). In the simulation, a simple square two-dimensional lattice of active sites replaces the surface of the catalyst. Finite reaction rates for (i) diffusion of the reactive species on the surface, (ii) reaction of a CO molecule with an oxygen atom in a nearest neighbor site, and (iii) desorption of unreacted CO molecules, have been taken into account. The produced CO 2 desorbs instantly. The average coverage of O, CO and the CO 2 production rate for a steady state configuration, as a function of the normalized CO partial pressure (P CO ), shows two kinetic phase transitions. In the ZGB model these transitions occur at P CO ≈ 0.39 and P CO ≈ 0.53. For 0.39 < P CO < 0.53 a reactive ( CO 2 production) steady state is found. Outside of the interval, the only steady state is a poisoned catalyst of pure CO or pure O. Our results show that finite reaction rates shift the values in which these phase transitions occur.

scholarly journals A molecular theory of nematic–nematic phase transitions in mesogenic dimers

Soft Matter ◽  
2016 ◽  
Vol 12 (7) ◽  
pp. 2208-2220 ◽  
Author(s):  
Alexandros G. Vanakaras ◽  
Demetri J. Photinos
Keyword(s):  
Phase Transitions ◽  
Nematic Phase ◽  
Molecular Theory ◽  
Molecular Axis

Explicit molecular theory shows the second nematic phase of symmetric dimers to have a tightly twisted polar ordering of the transverse molecular axis.

Kinetic Constraints in the Phase Transitions of Chemisorbed Carbon Monoxide on Co{101̄0} at High Coverages

2000 ◽  
Vol 104 (19) ◽  
pp. 4684-4689 ◽  
Author(s):  
J. Gu ◽  
Y. Y. Yeo ◽  
W. S. Sim ◽  
D. A. King
Keyword(s):  
Carbon Monoxide ◽  
Phase Transitions

scholarly journals ANOMALY IN THE HEAT CAPACITY OF CRYSTALLINE CARBON MONOXIDE AT 18 K ASSOCIATED WITH ORIENTATIONAL ORDERING

1976 ◽  
Vol 5 (6) ◽  
pp. 567-571 ◽  
Author(s):  
Tooru Atake ◽  
Hiroshi Suga ◽  
Hideaki Chihara
Keyword(s):  
Carbon Monoxide ◽  
Heat Capacity ◽  
Orientational Ordering
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