Bimetallic Pd‐Au Nanoparticles Supported Monodisperse Porous Silica Microspheres as an Efficient Heterogenous Catalyst for Fast Oxidation of Benzyl Alcohol

Abstract A bimetallic heterogeneous catalyst in the form of PdAu nanoparticle supported monodisperse‐porous SiO 2 microspheres (PdAu@APTES@SiO 2 ) was prepared for fast oxidation of benzyl alcohol (BzOH). The mesoporous support obtained by an originally developed staged‐shape templated hydrolysis‐condensation protocol provided large surface area and high pore volume for parking of noble metal nanoparticles. PdAu@APTES@SiO 2 provided higher BzOH conversion, benzaldehyde (BzH) selectivity and BzH formation yield with respect to monometallic catalysts containing Pd or Au nanoparticles supported with SiO 2 microspheres. BzOH conversions and BzH formation yields higher than 95 % were obtained in 30 min at 80 °C. The maximum TON and TOF values were determined as 300 and 600 h −1 , respectively. BzOH conversions and TOF were also higher with respect to similar catalysts prepared using different supports also carrying PdAu nanoparticles. PdAu@APTES@SiO 2 exhibited good stability with a decrease of BzOH conversion less than 2.5 % over five consecutive runs.