Molybdenum Oxide Constructed by {Mo6O21}6- Pentagonal Unit Assembly and Its Redox Properties

Molybdenumoxides are widely used in various fields due to theirelectronic and structural characteristics. These materials can generatelattice oxygen defects by reduction treatments, which sometimes playcentral roles in various applications. However, little has been understoodabout their properties since it is difficult to increase the amountof lattice oxygen defects due to the crystal structure changes inmost cases. Here, we report a new class of high-dimensionally structuredMo oxide (HDS-MoO (x) ) constructed by therandom assembly of {Mo6O21}(6-) pentagonal units (PUs). Since the PU is a stable structural unit,the structural network based on the PU hardly caused structural changesto make the lattice oxygen defects vanish. Consequently, HDS-MoO (x) could generate a substantial amount of latticeoxygen defects, and their amount was controllable, at least in therange of MoO2.64-MoO3.00. HDS-MoO (x) was more redox active than typical Mo oxide(alpha-MoO3) and demonstrated an oxidation ability forgas-phase isopropanol oxidation under the reaction conditions, whereas alpha-MoO3 affords no oxidation products. We synthesized high-dimensionally structuredmolybdenumoxide (HDS-MoO) composed of {Mo6O21}(6-) pentagonal units. HDS-MoO could generate a substantial amount oflattice oxygen defects without causing crystal structure changes.HDS-MoO showed an oxidation ability for isopropanol oxidation, wheretypical molybdenum oxide could not show any oxidation ability.

Automated summary

In this study, a new class of high-dimensionally structured molybdenum oxide (HDS-MoO(x)) was reported, which was constructed by the random assembly of {Mo6O21}(6-) pentagonal units (PUs). HDS-MoO(x) could generate a substantial amount of lattice oxygen defects without causing crystal structure changes. It showed higher oxidation ability compared to typical molybdenum oxide.