The reaction barrier for the first step is 9.0 kcal/mol for
the Au−O/ZSM-5 zeolite, much smaller than for the Au/ZSM-5 zeolite (43.0 kcal/mol).
For step 2, the reaction barriers are 4.4 kcal/mol for Au−O/ZSM-5 and 30.8 kcal/mol for
Au/ZSM-5, respectively.