Engineering metal-oxide interface by depositing ZrO2 overcoating on Ni/Al2O3 for dry reforming of methane

Zirconium oxide (ZrO2) was deposited onto Ni/Al2O3 catalyst as overcoating by atomic layer deposition (ALD) for dry reforming of methane (DRM). High-temperature heating during H-2-reduction could transform the ALD-prepared ZrO2 thin film to tetragonal phase and crack the encapsulating layer on Ni sites, which constructed a beneficial Ni-ZrOx interface. Interfacial surface oxygen vacancies on ZrO2 overcoating were induced by the partial reduction of ZrO2 surface during high-temperature H-2 reduction, with the assistance of Ni. During DRM, the interfacial oxygen vacancies enhanced CO2 activation by dissociating CO2 and releasing active O, thereby limiting carbon formation. For DRM at 700 degrees C and 800 degrees C, Ni/Al2O3 with 5 cycles of ZrO2 ALD overcoating enhanced both activity and stability significantly. For a 100-h DRM test at 600 degrees C, no deactivation was observed for the Ni/Al2O3 catalyst with 10 cycles of ZrO2 ALD overcoating, as compared to 59% relative activity loss of Ni/Al2O3.

Automated summary

ZrO2 overcoating by atomic layer deposition (ALD) on the catalyst improves the activity and stability in the dry reforming of methane (DRM) process.