Tailoring titanium species to boost bifunctional Au‐<scp>TS</scp>‐1 catalyzing propylene hydro‐oxidation

Abstract The speciation of titanium is a crucial factor that influences the catalytic activity of TS‐1, an efficient catalyst for selective oxidations. This study investigates how different thermal treatment conditions affect titanium speciation in TS‐1. A variety of characterization techniques were employed to identify changes in the titanium speciation, while propylene hydro‐oxidation served as a probe reaction to assess the impact of these changes on the synergistic interaction between TS‐1 and Au nanoparticles. Our findings reveal that conventional thermal calcination induces a transformation of some titanium species from tetrahedral coordination Ti 4+ to extra‐framework anatase TiO 2 . In contrast, thermal treatment under an inert nitrogen atmosphere at lower temperatures effectively mitigates this transformation, resulting in a reduced amount of extra‐framework TiO 2 . This optimization leads to enhanced utilization of H 2 O 2 and decreased isomerization conversion of propylene oxide, ultimately boosts bifunctional Au‐TS‐1 catalyzing propylene hydro‐oxidation.