Adsorption and Oxidative Desorption of Acetaldehyde over Mesoporous Fe_xO_yH_z/Al₂O₃

Abstract

Fe x O y H z nanostructures were incorporated into commercially available and highly porous alumina using the temperature-regulated chemical vapor deposition method with ferrocene as an Fe precursor and subsequent annealing. All processes were conducted under ambient pressure conditions without using any high-vacuum equipment. The entire internal micro- and mesopores of the Al 2 O 3 substrate with a bead diameter of ∼2 mm were evenly decorated with Fe x O y H z nanoparticles. The Fe x O y H z /Al 2 O 3 structures showed substantially high activity for acetaldehyde oxidation. Most importantly, Fe x O y H z /Al 2 O 3 with a high surface area (∼200 m 2 /g) and abundant mesopores was found to uptake a large amount of acetaldehyde at room temperature, and subsequent thermal regeneration of Fe x O y H z /Al 2 O 3 in air resulted in the emission of CO 2 with only a negligibly small amount of acetaldehyde because Fe x O y H z nanoparticles can catalyze total oxidation of adsorbed acetaldehyde during the thermal treatment. Increase in the humidity of the atmosphere decreased the amount of acetaldehyde adsorbed on the surface due to the competitive adsorption of acetaldehyde and water molecules, although the adsorptive removal of acetaldehyde and total oxidative regeneration were verified under a broad range of humidity conditions (0–70%). Combinatory use of room-temperature adsorption and catalytic oxidation of adsorbed volatile organic compounds using Fe x O y H z /Al 2 O 3 can be of potential application in indoor and outdoor pollution treatments.

Mesoporous SiO2 Particles Combined with Fe Oxide Nanoparticles as a Regenerative Methylene Blue Adsorbent

“…The central position of the binding energy of the Fe 2p 3/2 core-level peak (∼710 eV) was closer to Fe 3 O 4 states (∼710.4 eV) rather than α-Fe 2 O 3 states (∼710.9 eV) . However, one should note that many elements resulting from final state effects were contributed to the Fe 2p 3/2 XPS peak; − the Fe 2p 3/2 peak of Fe oxide can be fitted using six components arising from final state relaxation effects (Figure S1). − Considering this complexity and broadness of the Fe 2p core-level peak resulted from the final state effect, we cannot exclude the possibility of coexistence of Fe 3 O 4 and α-Fe 2 O 3 states.…”

Positive Effects of Impregnation of Fe-oxide in Mesoporous Al-Oxides on the Decontamination of Dimethyl Methylphosphonate

“…However, the inherent complexity and broadness of Fe 2p core-level XPS spectrum results from the existence of multiple elements due to the final state relaxation effects prevent us from determining the exact oxidation state of Fe-oxide. It is likely that Fe-oxide consisted of a complex mixture of various oxidized Fe-oxide, such as Fe 3 O 4 and α-Fe 3 O 4 , which was indicated by our previous analysis on the Fe-oxide/Al 2 O 3 sample that was prepared via a similar TR-CVD and post-annealing process by means of Mössbauer spectroscopy [24].…”

“…The crystallinities of bare Al 2 O 3 and Fe-oxide/Al 2 O 3 samples were also studied by measuring their XRD patterns (Figure 1f). A pronounce XRD peak at 67 • was observed with broad feature consist of multiple peaks in the 2θ range of 20~50 • for the case of bare Al 2 O 3 , which can be attributed to χ-phase of Al 2 O 3 [24]. No additional XRD peaks appeared upon the Fe-oxide deposition and subsequent 750 • C-annealing, and the Fe-oxide/Al 2 O 3 sample also exhibited very similar XRD patterns with bare Al 2 O 3 , which can be attributed to the small size of Fe-oxide moiety existed in Fe-oxide/Al 2 O 3 .…”

“…The Fe-oxide/Al 2 O 3 samples were prepared by a temperature regulated chemical vapor deposition (TR-CVD) of Fe-oxide on mesoporous Al 2 O 3 , followed by a thermal annealing at 750 • C. TR-CVD of Fe-oxide on Al 2 O 3 particles was carried out using a stainless-steel chamber containing 67.5 g of bis(cyclopentadienyl)iron (Fe(Cp) 2 ) and 100 g of Al 2 O 3 particles [24]. The porous Al 2 O 3 particles (particle size of 2.0 mm) were purchased from BASF (Ludwigshafen, Germany) and used as a substrate without a further treatment, while Fe(Cp) 2 that was bought from Sigma Aldrich (Saint Louis, MO, USA) was used as a Fe precursor.…”

A Laser-Activated Membrane Introduction Mass Spectrometry Study of Proton Spillover Promoted Alkane Dehydrogenation

“…We now describe improvements afforded by the use of γ-alumina bead-supported catalysts. Bead-supported catalysts are prevalent in industrial fluid bed catalytic cracking units due to their lower attrition losses and activity advances. − Today, γ-alumina and silica–alumina beads are in widespread use as supports for finely dispersed catalyst materials. − Our coworkers have demonstrated the efficacy of combinatorial analyses of γ-Al 2 O 3 bead-supported catalysts for light alkane dehydrogenation. ,, This study uses the same platinized γ-alumina beads for the study of methylcyclohexane (MCH) dehydrogenation to toluene and H 2 (eq. ): , …”