TY - JOUR
T1 - Microcalorimetric studies of interactions of ethene, isobutene, and isobutane with silica-supported Pd, Pt, and PtSn
AU - Natal-Santiago, M. A.
AU - Podkolzin, S. G.
AU - Cortright, R. D.
AU - Dumesic, J. A.
PY - 1997
Y1 - 1997
N2 - Microcalorimetric measurements were made of the interaction of hydrogen, ethene, isobutene and isobutane at 300 K with silica-supported Pt, Pd, and PtSn catalysts. The initial heats of hydrogen adsorption on silica-supported Pd and Pt are 104 and 95 kJ/mol, respectively. The presence of Sn decreases the saturation uptake of hydrogen on the PtSn sample. The initial heats of ethene interaction with Pd/silica and Pt/silica are 170 and 145 kJ/mol, respectively. The presence of Sn decreases the initial heat to 115 kJ/mol on the PtSn sample. The initial heats of isobutene interaction with silica-supported Pd and Pt are 160 and 190 kJ/mol, respectively. The presence of Sn decreases the initial heat to 125 kJ/mol on the PtSn sample. It appears that ethene and isobutene adsorb dissociatively on silica-supported Pd and Pt to form alkyHdyne species at 300 K, with an average strength of carbon-metal bonds for these species near 230 kJ/mol. Ethene and isobutene adsorb on silica-supported PtSn to form di-σ- and π-bonded alkene species at 300 K, with an average strength of carbon-metal bonds for these species near 190 and 130kJ/mol, respectively. Isobutane appears to adsorb dissociatively on a small number of sites on silica-supported Pd and Pt, and this dissociation is also inhibited by Sn on PtSn samples.
AB - Microcalorimetric measurements were made of the interaction of hydrogen, ethene, isobutene and isobutane at 300 K with silica-supported Pt, Pd, and PtSn catalysts. The initial heats of hydrogen adsorption on silica-supported Pd and Pt are 104 and 95 kJ/mol, respectively. The presence of Sn decreases the saturation uptake of hydrogen on the PtSn sample. The initial heats of ethene interaction with Pd/silica and Pt/silica are 170 and 145 kJ/mol, respectively. The presence of Sn decreases the initial heat to 115 kJ/mol on the PtSn sample. The initial heats of isobutene interaction with silica-supported Pd and Pt are 160 and 190 kJ/mol, respectively. The presence of Sn decreases the initial heat to 125 kJ/mol on the PtSn sample. It appears that ethene and isobutene adsorb dissociatively on silica-supported Pd and Pt to form alkyHdyne species at 300 K, with an average strength of carbon-metal bonds for these species near 230 kJ/mol. Ethene and isobutene adsorb on silica-supported PtSn to form di-σ- and π-bonded alkene species at 300 K, with an average strength of carbon-metal bonds for these species near 190 and 130kJ/mol, respectively. Isobutane appears to adsorb dissociatively on a small number of sites on silica-supported Pd and Pt, and this dissociation is also inhibited by Sn on PtSn samples.
KW - Density-functional theory
KW - Ethene
KW - Isobutene
KW - Isohutane
KW - Microcalonmetry
KW - Nydrogen
KW - Palladium
KW - Platinum
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U2 - 10.1023/a:1019004720871
DO - 10.1023/a:1019004720871
M3 - Article
AN - SCOPUS:0000033439
SN - 1011-372X
VL - 45
SP - 155
EP - 163
JO - Catalysis Letters
JF - Catalysis Letters
IS - 3
ER -