Zeolite-supported Molecular Metal Complex Catalysts - Atomically-Precise Methods for Synthesis of Solid Catalysts - page 43

d n 9 r 4 n g | 7

.

13 C CP-MAS NMR spectra (75.4 MHz) of the sample formed from Rh(Z 2 -
C 2 H 4 ) 2 (acac) and zeolite HY and then exchanged with 13 C-labeled ethene.
(a) Variable-temperature spectra showing the temperature dependence
of the signal intensity. (b) Spectrum obtained at low temperature after
heating and subsequent cooling of the sample, which demonstrates the
results of a reverse-spillover reaction. The signal at d ¼ 5.7 ppm corres-
ponds to ethane.
Reproduced from ref. 24.

Figure 2.8

from the sample containing only chemisorbed species to the sample con-
taining largely physisorbed species.
When the zeolite-supported ruthenium complexes were tested in ethene
dimerization reaction, the data show that only the chemisorbed species are
active for this reaction. The turnover frequencies expressed with respect to
the amount of chemisorbed species are virtually the same among the sam-
ples at steady state. Furthermore, butene selectivity, which is influenced by
the residence time of reactant ethene with respect to the number of 'cata-
lytically active species (chemisorbed species)' in a flow reactor, shows the
same value for the sample containing only chemisorbed and a mixture of