Details
| Translated title of the contribution | Composition and Catalytic Activity of Hierarchically Structured Oxide Catalysts - Part 1 |
|---|---|
| Original language | German |
| Pages | 805, 872-877 |
| Volume | 75 |
| Issue number | 7 |
| Journal | Chemie-Ingenieur-Technik |
| Publication status | Published - Jul 2003 |
Abstract
Using different preparative methods two titania carriers (micrometer size spray granulate and nano scale titania) were synthesized in the anatase modification with various BET surfaces and then functionalized catalytically with vanadia, molybdic anhydride (MoO3) or titania. The oxidative dehydrogenation of short chain n-alkanes was a suitable model reaction to demonstrate the correlation between catalyst structure and catalytic properties. In the case of surface area-poor spray granulates the conversion of propane increases with increasing coverage of vanadia, molybdic anhydride, or titania on the titania carrier but propane selectivity decreases. In the case of the surface-rich nanometer-titania carrier the selectivity in addition to the activity increases with increasing content of active components to the catalyst. According to the knowledge up to the present the active components precipitate out as nano-particulate cover on the carrier surface that detailed measurements (SIMS-depth profile, analytical TEM) have still to find. The catalytic effect of this hierarchical construction is more favorable than that of the individual components, so that probably the contact zone between the nano particles and the carrier is of special significance. The number of these contacts increases with smaller particle size (more contacts per unit area) and increasing content in active components as long as they are present as finely isolated particles. In the future the construction of the catalyst is to be optimized and the underlying mechanisms to be clarified. The discussion covers statement of the problem; description of the experiments (preparation of the titania carrier as spray granulates, and as nanometer dimensions by hydrolysis of titanyl sulfate); preparation of the catalysts; physical-chemical characterization; catalytic evaluation in propane dehydrogenation; and results (physical-chemical characterization and catalytic evaluation in the oxidative dehydrogenation of propane).
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Chemical Engineering(all)
- General Chemical Engineering
- Engineering(all)
- Industrial and Manufacturing Engineering
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In: Chemie-Ingenieur-Technik, Vol. 75, No. 7, 07.2003, p. 805, 872-877.
Research output: Contribution to specialist publication › Contribution in non-scientific journal › Transfer
}
TY - GEN
T1 - Aufbau und katalytische Aktivität hierarchisch strukturierter Oxid-Katalysatoren - Teil 1
AU - Stelzer, Jean Boris
AU - Kosslick, Hendrick
AU - Caro, Jürgen
AU - Habel, Daniela
AU - Feike, Egbert
AU - Schubert, Helmut
PY - 2003/7
Y1 - 2003/7
N2 - Using different preparative methods two titania carriers (micrometer size spray granulate and nano scale titania) were synthesized in the anatase modification with various BET surfaces and then functionalized catalytically with vanadia, molybdic anhydride (MoO3) or titania. The oxidative dehydrogenation of short chain n-alkanes was a suitable model reaction to demonstrate the correlation between catalyst structure and catalytic properties. In the case of surface area-poor spray granulates the conversion of propane increases with increasing coverage of vanadia, molybdic anhydride, or titania on the titania carrier but propane selectivity decreases. In the case of the surface-rich nanometer-titania carrier the selectivity in addition to the activity increases with increasing content of active components to the catalyst. According to the knowledge up to the present the active components precipitate out as nano-particulate cover on the carrier surface that detailed measurements (SIMS-depth profile, analytical TEM) have still to find. The catalytic effect of this hierarchical construction is more favorable than that of the individual components, so that probably the contact zone between the nano particles and the carrier is of special significance. The number of these contacts increases with smaller particle size (more contacts per unit area) and increasing content in active components as long as they are present as finely isolated particles. In the future the construction of the catalyst is to be optimized and the underlying mechanisms to be clarified. The discussion covers statement of the problem; description of the experiments (preparation of the titania carrier as spray granulates, and as nanometer dimensions by hydrolysis of titanyl sulfate); preparation of the catalysts; physical-chemical characterization; catalytic evaluation in propane dehydrogenation; and results (physical-chemical characterization and catalytic evaluation in the oxidative dehydrogenation of propane).
AB - Using different preparative methods two titania carriers (micrometer size spray granulate and nano scale titania) were synthesized in the anatase modification with various BET surfaces and then functionalized catalytically with vanadia, molybdic anhydride (MoO3) or titania. The oxidative dehydrogenation of short chain n-alkanes was a suitable model reaction to demonstrate the correlation between catalyst structure and catalytic properties. In the case of surface area-poor spray granulates the conversion of propane increases with increasing coverage of vanadia, molybdic anhydride, or titania on the titania carrier but propane selectivity decreases. In the case of the surface-rich nanometer-titania carrier the selectivity in addition to the activity increases with increasing content of active components to the catalyst. According to the knowledge up to the present the active components precipitate out as nano-particulate cover on the carrier surface that detailed measurements (SIMS-depth profile, analytical TEM) have still to find. The catalytic effect of this hierarchical construction is more favorable than that of the individual components, so that probably the contact zone between the nano particles and the carrier is of special significance. The number of these contacts increases with smaller particle size (more contacts per unit area) and increasing content in active components as long as they are present as finely isolated particles. In the future the construction of the catalyst is to be optimized and the underlying mechanisms to be clarified. The discussion covers statement of the problem; description of the experiments (preparation of the titania carrier as spray granulates, and as nanometer dimensions by hydrolysis of titanyl sulfate); preparation of the catalysts; physical-chemical characterization; catalytic evaluation in propane dehydrogenation; and results (physical-chemical characterization and catalytic evaluation in the oxidative dehydrogenation of propane).
UR - http://www.scopus.com/inward/record.url?scp=0141679082&partnerID=8YFLogxK
M3 - Beitrag in Publikumszeitung/-zeitschrift
AN - SCOPUS:0141679082
VL - 75
SP - 805, 872-877
JO - Chemie-Ingenieur-Technik
JF - Chemie-Ingenieur-Technik
SN - 0009-286X
ER -