Recent Developments in Gold Nanomaterial Catalysts for Oxidation Reaction through Green and Sustainable Routes - Advanced Materials for Agriculture, Food and Environmental Safety - page 207

0.35 wt% Au / Ti - SiO 2

6

Silylated

4

Non-Silylated

2

2
Time on Stream (h)

0 1 3 4 5

Figure 8.8 Improved performance of Au-Ti-SiO 2 catalysts during direct propylene
epoxidation reaction.

10

C 3
Conversion/ %

5

100

95

PO
Selectivity/ %

90

85
40
30
20
10
0

H 2
Eiciency/ %

0 50 100

Time on stream/ min

150 200 250 300

Figure 8.9 Controlled deactivation of Au/Ti-SiO 2 catalysts in the presence of trimethylamine
in the reaction feed. Reproduced with permission from [67].

Prof. Delgass group indeed demonstrated that these are the most active
Au/TS-1 catalysts reported, where a stable PO production is observed at
temperatures ranging from 140-200 C [73-74, 75].

Another important point to be highlighted is the hydrogen ei ciency
during direct propylene epoxidation using molecular H 2 and O 2 over

°