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

Abstract

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 °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 O2 into active oxygen species (O*) should be the rate‐determining step for CH4 conversion.

Photothermal catalytic C1 conversion on supported catalysts

“…Overall, although semiconductor-based supports are widely used in photothermal catalyst applications, ongoing research aims to explore new materials and approaches to further advance this field. 36,72,73 In these approaches, heat energy is harnessed to drive catalytic reactions instead of being dissipated to the surrounding environment through convection and conduction. Through structural control, interface engineering, multifunctional assembly and nanoscale effects for meticulous selection and optimization of both the active component and support structure, researchers can develop highly efficient systems capable of catalyzing complex chemical transformations with exceptional precision and control.…”

Water-dispersible X-ray scintillators enabling coating and blending with polymer materials for multiple applications

“…The HNTs exhibit different surface charge on the outer (Si-O-Si) and inner (Al-OH) surfaces 28 , whereby the stable negative charge on the outer surface can prevent aggregation of the nanotubes 29 . Other attractive properties of HNTs include their good biocompatibility 30 , 31 , low toxicity 32 , high stability 33 , hydrophilicity 34 , processability 35 , and low-cost 36 making HNTs promising candidates for the fabricating of composite materials. Though there is still some controversy on the potential toxicity upon some special items 37 , HNTs remain a popular topic in material science including biomedical uses with a growing trend of attention 38 .…”

“…Though there is still some controversy on the potential toxicity upon some special items 37 , HNTs remain a popular topic in material science including biomedical uses with a growing trend of attention 38 . The existence of silanol groups on the surface allows straightforward surface functionalization 36 , 39 . These favourable properties of HNTs inspired us to explore them as a substrate to prepare lead-free nanocomposites with X-ray scintillating abilities, which may have good water-dispersibility and desirable compatibility in polymeric matrices.…”

Low-Temperature Catalytic Methane Deep Oxidation over Sol-gel derived Mesoporous Hausmannite (Mn3O4) Spherical Particles

“…[18] Despite the above-mentioned properties favourable for their application as a catalyst, Mn3O4 is more often used as a noble metal catalyst carrier in CH4 oxidation reactions rather than an active phase like MnO2. [23] Moreover, a systematic study on the CH4 oxidation over Mn3O4 has not been yet established.…”