Iron and molybdenum modified phosphotungstates towards selective oxidation of styrene to benzaldehyde

Iron and molybdenum modified phosphotungstates (FeMoPW) were synthesized by reaction of H 3 PW 12 O 40 (PW) with Fe(NO 3 ) 3 .9 H 2 O and (NH 4 ) 6 Mo 7 O 24 .4 H 2 O, followed by calcined, and characterized by XRD, FT-IR, UV–vis, SEM, TEM and XPS to determine the surface composition and structure. The as-prepared FeMoPW was utilized as a catalyst for solvent-free oxidation of styrene with hydrogen peroxide oxidant and it exhibited higher styrene conversion (60%) and high selectivity to benzaldehyde (90%). The FeMoPW catalyst converted styrene into benzaldehyde by synergic effect of FePW and Fe 2 (MoO 4 ) 3 active sites on the surface. The recovery and reusability of the catalyst were evaluated and excellent reusability was achieved. In addition, in situ adsorptions of styrene and H 2 O 2 on the catalyst surface were conducted and the reaction mechanism via forming styrene oxide, and benzyl alcohol intermediates was proposed. Iron and molybdenum modified phosphotungstates was utilized as a catalyst for solvent-free oxidation of styrene with hydrogen peroxide oxidant, exhibiting higher conversion of styrene with 60% and high selectivity to BzH with 90%. The higher catalytic activity of this catalyst is ascribed to mutual action of components FePW and Fe 2 (MoO 4 ) 3 crystallines and the reaction mechanism via producing styrene oxide, followed by forming BzOH intermediates is proposed.