Characterization of SiO₂ Deposited by CVD on Mo_xO_y/Al₂O₃ using NMR and TOF‐SIMS

Abstract

Silica (SiO 2 ) is deposited onto the surface of Mo x O y /Al 2 O 3 using CVD in a fluidized bed. The resulting deposit is characterized using N 2 physisorption, inductively coupled plasma (ICP) spectrometry, 29 Si nuclear magnetic resonance (NMR) and time of flight-secondary ion mass spectrometry (TOF-SIMS). The ICP and physisorption results show that the amount deposited on the surface reaches a plateau value after 30-60 min. Based on the NMR and TOF-SIMS analysis, this plateau value corresponds to 2-3 monolayers. The surface coverage is not uniform, and the presence of Mo on the exterior surface of Al 2 O 3 hinders the deposition of silica.