The decrease of activity over 1.8 atoms of Re per nm2of support was correlated to loss of active site due to the formation of aggregates of ReOx.
This decrease of activity is likely to reflect the suspension of cognitive processes that are active at rest [7], although the precise nature of these processes remains currently debated [8], [9], [10], [11].
Entrapped yeast shows a remarkable decrease of activity compared to the free cells.
Substitution of phenylene framework of salphen ligand by chlorine atom led to decrease of activity in PO/CO2 copolymerization.
The nickel addition shifted all the reaction system towards high temperature due to the decrease of activity.
However, the additions of Au and Pt to Ag/Al2O3 only resulted in a decrease of activity for the C3H6-SCR of NOx.
The Fe/γ-Al2O3 catalyst showed a reasonable stability, a relatively low decrease of activity (15%) being observed after three successive runs.
It was observed that the decrease of activity at higher temperatures resulted from a strong dependency of the first-order decay rate constant on temperature.
Mutation of Phe179 to serine, a small hydrophilic residue, produced a moderate decrease of activity, and replacement by glutamine, a hydrophilic residue with a larger side chain, significantly impaired activity (Fig. 3d), confirming the importance of the hydrophobic interaction between Phe179 and H3P30.
Furthermore, the preparation of L-Tle was successfully performed in a recirculating packed bed reactor (RPBR) system and immobilized PGA exhibited a long-term stability for 51 days with a slight decrease of activity.
FTS tests indicated a medium amount of nitrogen (≤8.3 wt%) did not show obvious effect on the activity of the catalyst, but a much higher amount of nitrogen (≥16.5 wt%) could result in a significant decrease of activity.
