appear. These parameters can be associated to the relevance of local transport (the density of active sites is approximated by L M,9BC OPQ /s 9BC ), availability of surface redox-active species and surface redox activity. The equation implies that olefin formation appears to be a local surface process for which the electronic properties of the catalyst volume do not play a major role. Site isolation of the active sites also has a positive effect on the selectivity to the olefin, since the lower the L M,9BC