Highly Active PdO/Mn O /CeO 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) and oxidative MnO /Pd ions to form PdO/Mn O /CeO (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, Mn O , and CeO , and hence HPMC could show excellent performance on photoassisted thermal catalytic CH combustion that its light-off temperature was sharply reduced to be 180 °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 into active oxygen species (O*) should be the rate-determining step for CH conversion.