Facet-dependent catalysis of γ-Bi2MoO6 for selective oxidation of isobutene to methacrolein

Abstract

The shape effect of γ-Bi₂MoO₆ catalysts on the selective oxidation of isobutene to methacrolein was investigated in terms of their predominantly exposed crystal facets and surface termination. γ-Bi₂MoO₆ nanosheets and microflowers, mainly exposing the {010} facet, were hydrothermally synthesized with the aid of sodium dodecyl sulfate and ethylene glycol, but the surface was terminated by molybdenum and bismuth species, respectively. γ-Bi₂MoO₆ nanosheets showed a significantly higher activity for the selective oxidation of isobutene to methacrolein than γ-Bi₂MoO₆ microflowers with an average isobutene conversion of 88% and a methacrolein selectivity of 67% within 12 hours, primarily because of the preferential termination of the reactive molybdenum species on the {010} facets.