Hollow Mesoporous Co₃O₄–CeO₂ Composite Nanotubes with Open Ends for Efficient Catalytic CO Oxidation

Abstract

Catalytic performance is heavily dependent on how the structures of nanomaterials are designed. Co3O4–CeO2 composite nanotubes with open ends and mesoporous structures were fabricated through a facile and environmentally friendly reaction. The mesoporous Co3O4 nanotubes were synthesized by the calcination of cobalt–aspartic acid (Co–Asp) nanowires and coated with a CeO2 shell. The composite nanotubes were characterized by SEM, TEM, XRD, and X‐ray photoelectron spectroscopy. The composite materials comprise a combination of Co3O4 nanotubes and CeO2 nanoparticles with a hollow and mesoporous bimetallic oxide structure. The large BET surface area led to a higher degree of accessible active sites compared with other Co3O4–CeO2 composite nanomaterials with other structures. The resulting Co3O4–CeO2‐26.3 wt % composite nanotubes, with a CeO2 content of approximately 26.3 wt %, achieved 100 % CO conversion at 145 °C. Additionally, the synergistic effect between the two metal oxides comprising the Co3O4–CeO2 composite nanotubes was demonstrated by the enhanced catalytic activity compared with pure Co3O4 nanotubes and CeO2 nanoparticles.

Synthesis and properties of Pt/TiN catalyst for low-temperature air purification from carbon monoxide

“…Catalytic oxidation of CO has received considerable attention due to its wide applications in exhaust gas after-treatment, CO oxidation for proton exchange membrane fuel cells and air purification systems. In the scientific literature, a huge number of works are devoted to the catalytic oxidation of CO (see, for example, publications [32][33][34][35][36][37][38][39][40] and references to them). Our attention in this paper is devoted to low-temperature oxidation of CO in catalytic air purification systems.…”

In Situ Synthesized Silica‐Supported Co@N‐Doped Carbon as Highly Efficient and Reusable Catalysts for Selective Reduction of Halogenated Nitroaromatics

“…Figure a displays the Co 2p XPS spectra of the Co 3 O 4 /SiO 2 ‐500, Co@CN/SiO 2 ‐ T ( T =300, 400, 500, 600, 700) and Co@CN/SiO 2 ‐imp‐500 samples. It could be found that the Co 3 O 4 /SiO 2 ‐500 sample exhibited a symmetric Co 2p 3/2 primary spectrum peaked at the binding energy (BE) of 780.7 eV, which was assigned to Co 3 O 4 . For the Co@CN/SiO 2 ‐ T samples, a broadened non‐symmetric Co 2p 3/2 peak was observed, which could be deconvoluted into two or three components.…”

“…It could be found that the Co 3 O 4 /SiO 2 -500 sample exhibited a symmetric Co 2p 3/2 primary spectrum peaked at the binding energy (BE) of 780.7 eV, which was assigned to Co 3 O 4 . [34,35] For the Co@CN/SiO 2 -T samples, a broadened non-symmetric Co 2p 3/2 peak was observed, which could be deconvoluted into two or three components. The Co@CN/SiO 2 -300 had two peaks positioned at the BEs of 780.7 eV and 782.5 eV, corresponding to Co 3 O 4 and CoÀ N species, respectively.…”

1D confined materials synthesized via a coating method for thermal catalysis and energy storage applications

“…Another 1D confined catalyst, a hollow Co 3 O 4 @CeO 2 NT catalyst, was also designed for CO oxidation. 151 CeO 2 was coated upon hollow Co 3 O 4 NTs which were synthesized via a hydrothermal route using the precipitation method with hexamethylenetetramine as the precipitant. The effect of CeO 2 content is investigated and it is found that Co 3 O 4 @CeO 2 NTs with 26.3 wt% CeO 2 show the best activity (100% CO conversion at 418 K).…”