Construction of Pd/Mn3O4 heterojunction catalyst for efficient photothermal synergetic catalytic propane total oxidation

Abstract

• Pd/Mn 3 O 4 heterojunction catalyst was constructed by impregnation - pyrolysis - oxidation strategy. • Strong metal-support interaction effect between Pd and Mn 3 O 4 make the surface electron rich. • Formation of p-n junction between Pd and Mn 3 O 4 promoted the charge separation and the migration of carriers. Photothermal synergistic low-temperature catalytic volatile organic compounds (VOCs) degradation has an advantage on energy efficiency and reduction of carbon emissions. Herein, an impregnation-pyrolysis-oxidation strategy was adopted to synthesize Pd/Mn 3 O 4 heterojunction catalyst. Under photothermal synergistic conditions, 0.60Pd/Mn 3 O 4 catalyst exhibited an excellent activity for propane total oxidation, with a T 90 value of 219.1 ℃, which was 115.3 ℃ lower than that of Mn 3 O 4 . Enhancement effect of the heterojunction structure on photothermal synergy was detected by various characterization techniques and density functional theory calculation. The presence of Pd species enhanced the low-temperature reducibility of Mn 3 O 4 . Meanwhile, O 2 molecules were more easily activated at the Pd sites and overflow to the surface of Mn 3 O 4 for reaction. Besides, the formation of p-n junction between Pd species and Mn 3 O 4 in heterojunction structure promoted the charge separation and the migration of carriers, and boosted the generation of oxygen free radical, resulting in a significant improvement in photothermal catalytic activity. Overall, this study provided new strategy and deep insight for constructing heterojunction to enhance photothermal catalytic performance of VOC elimination.