Highly Active PdO/Mn3O4/CeO2 Nanocomposites Supported on One Dimensional Halloysite Nanotubes for Photoassisted Thermal Catalytic Methane Combustion

In this work, we have successfully triggered the aqueous auto-redox reactions between reductive Ce(OH)(3) and oxidative MnO4-/Pd2+ ions to form PdO/Mn3O4/CeO2 (PMC) nanocomposites. PMC could spontaneously self-assemble into compact encapsulation on the surface of halloysite nanotubes (HNTs) to form the final one dimensional HNTs supported PMCs (HPMC). It is identified that there exists strong synergistic effects among the components of PdO, Mn3O4, and CeO2, and hence HPMC could show excellent performance on photoassisted thermal catalytic CH4 combustion that its light-off temperature was sharply reduced to be 180 degrees C under visible light irradiation. Based on detailed studies, it is found that the catalytic reaction process well follows the classic MVK mechanism, and adsorption/activation of O-2 into active oxygen species (O*) should be the rate-determining step for CH4 conversion.

Automated summary

By triggering the aqueous auto-redox reactions between reductive Ce(OH)(3) and oxidative MnO4-/Pd2+ ions, PdO/Mn3O4/CeO2 (PMC) nanocomposites were formed, showing strong synergistic effects. The HPMC nanocomposites exhibited excellent performance in photoassisted thermal catalytic CH4 combustion, with a reduced light-off temperature of 180 degrees C under visible light irradiation. The catalytic reaction process followed the classic MVK mechanism, with O-2 adsorption/activation into active oxygen species (O*) being the rate-determining step for CH4 conversion.