aAutonomous University of Baja California, Faculty of Engineering, Architecture and Design – Doctorate Program in Sciences and Engineering, CP 22860,
Ensenada, B.C., Mexico
bNational Autonomous University of Mexico, Center for Nanosciences and
Nanotechnology, CP 22860, Ensenada, B.C., Mexico
cAutonomous University of Baja California, Faculty of Engineering, Architecture and Design, CP 22860, Ensenada, B.C., Mexico
Journal of Ovonic Research 2024, 20(3),405-415; https://doi.org/10.15251/JOR.2024.203.405
A tungsten oxide load at submonolayer coverage of alumina renders highly dispersed dimeric polytungstate (octahedral and distorted octahedral coordination) and isolated monotungstate (tetrahedral) species. The polytungstate/monotungstate proportion increases when approaching monolayer. Crystalline WO3 nanoparticles emerge at higher loads. All components display hexavalent oxidation; yet, tungsten _ oxide (W–O–W) and tungsten _ oxide _ alumina (W–O–Al) interactions were discerned by X__ ray photoelectron spectroscopy of the WOx/Al2O3 materials herein prepared with 1, 3, and 5 weight percentages. The 5 wt % sample displayed the highest intensity percentage of W–O–Al species correlated to the highest methanol conversion (45 %), ascribed to the appearance of the weak acidity disclosed by temperature _ programmed desorption of ammonia.

