Carbon-Modified Mesoporous Anatase/TiO2(B) Whisker for Enhanced Activity in Direct Synthesis of Hydrogen Peroxide by Palladium

The regulation of the interaction between H2O2 and its catalysts is a promising route to achieve high productivity and selectivity towards H2O2. Herein, mesoporous anatase/TiO2(B) whisker (mb-TiO2) modified with heterogeneous carbon was prepared as the support of Pd-based catalysts for the direct synthesis of H2O2. The morphology and structure of the catalyst were investigated by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Brunner-Emmet-Teller measurements, and X-ray photoelectron spectroscopy. The interaction between H2O2 and the support was studied by isothermal calorimeter. The carbon heterogeneous modification can weaken the interaction between H2O2 and the support, then accelerate the desorption of H2O2 and reduce the re-adsorption of H2O2 in the reaction medium. Meanwhile, the synergistic effects between TiO2 and Pd nanoparticles are not influenced by the heterogeneous carbon distribution. The catalyst exhibits better performance for the synthesis of H2O2 compared with the corresponding unmodified catalyst; the productivity of H2O2 increases more than 40%, which can be ascribed to the decrease of further H2O2 conversion under the weakened interaction.