Probing the Catalytic Active Sites of Mo/HZSM-5 and Their Deactivation during Methane Dehydroaromatization

Summary Molybdenum supported on zeolite HZSM-5 is the most studied catalyst for methane dehydroaromatization. However, nature of its catalytic sites and their deactivation mechanisms remain unclear controversial. Here, we report further insights into this system: first, crystal size determines form location active MoCx species, thus performance; second, are preferentially deactivated over acid sites, when nano-sized HZSM-5; third, particles that traditionally considered detrimental to reaction can serve as if they properly protected from coke deposition. These findings lead us develop an “encapsulation” strategy, which reconciles rates enabling a full utilization both consequently leading 10-fold increase in lifetime. Encapsulation also allows design experiments confirm role sites.