TY - JOUR
T1 - TPD characterization of surface adsorption sites of model Ziegler-Natta polymerization catalysts
AU - Kim, Seong Han
AU - Somorjai, Gabor A.
N1 - Funding Information:
This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Material Science Division, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. The authors also acknowledge support from Montell USA.
PY - 2000/7/2
Y1 - 2000/7/2
N2 - The surface adsorption sites of titanium chloride films that can be used as model Ziegler-Natta polymerization catalysts have been investigated with temperature-programmed desorption (TPD) of various probe molecules. The adsorption sites can be differentiated depending on the heat of desorption of the molecule. Two titanium chloride films were produced by electron-induced chemical vapor deposition of TiCl4 and co-deposition of Mg and TiCl4 on gold substrates. The surfaces of both films were chlorine-terminated. 1,3,5-Trimethylbenzene (mesitylene) was found to be an effective and non-destructive molecule for TPD characterization of adsorption sites on the model catalysts. The film produced by the electron-induced chemical vapor deposition had a distribution of adsorption sites that were not thermodynamically stable and subject to high-temperature annealing, while the film prepared by the co-deposition had a stable surface structure that was composed of domains of the MgCl2(001) basal plane structure.
AB - The surface adsorption sites of titanium chloride films that can be used as model Ziegler-Natta polymerization catalysts have been investigated with temperature-programmed desorption (TPD) of various probe molecules. The adsorption sites can be differentiated depending on the heat of desorption of the molecule. Two titanium chloride films were produced by electron-induced chemical vapor deposition of TiCl4 and co-deposition of Mg and TiCl4 on gold substrates. The surfaces of both films were chlorine-terminated. 1,3,5-Trimethylbenzene (mesitylene) was found to be an effective and non-destructive molecule for TPD characterization of adsorption sites on the model catalysts. The film produced by the electron-induced chemical vapor deposition had a distribution of adsorption sites that were not thermodynamically stable and subject to high-temperature annealing, while the film prepared by the co-deposition had a stable surface structure that was composed of domains of the MgCl2(001) basal plane structure.
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U2 - 10.1016/S0169-4332(00)00131-8
DO - 10.1016/S0169-4332(00)00131-8
M3 - Article
AN - SCOPUS:0034226103
SN - 0169-4332
VL - 161
SP - 333
EP - 339
JO - Applied Surface Science
JF - Applied Surface Science
IS - 3
ER -