The Key Role of Nanocasting in Gold‐based Fe₂O₃ Nanocasted Catalysts for Oxygen Activation at the Metal‐support Interface

Abstract

The total oxidation of propane, a representative Volatile Organic Compound, has been studied using gold‐based α‐Fe2O3 catalysts. Catalysts consisting of gold nanoparticles confined in nanostructured Fe2O3 prepared by a nanocasting route present the highest catalytic activity for propane total oxidation, and the activity is significantly greater than those of gold‐based catalysts where iron oxide supports are prepared by other conventional methods, such as calcination. Detailed characterisation and Density‐functional theory (DFT) studies have been undertaken in order to explain the enhancement in catalytic properties. The presence of confined gold nanoparticles on the nanocast Fe2O3 facilitates the production of highly reactive oxygen vacancies at the metal‐support interface, increasing the catalyst performance. Both the development of a microporous/mesoporous structure in the iron oxide support and the presence of a mixed surface phase of Si and Fe oxides, seem to be key parameters, being both features inherent in the nanocasting process from silica templates. Additionally, the catalytic activity is enhanced due to other positive effects, which are closely related to the nanocasting preparation method: i) a higher contact surface area between partially confined small gold nanoparticles in the internal mesoporosity of the nanostructured support and the metal oxide and; ii) a more reducible support due to the presence of more active surface lattice oxygen.

Ultrasonic-assisted oxidation of cellulose to oxalic acid over gold nanoparticles supported on iron-oxide

“…To assess the effect of cavitation events on the cellulose conversion, the unreacted cellulose was recovered and analysed. 40–42 XRD patterns of ultrasonically treated cellulose under oxygen or air (0.15 MPa) were strikingly similar to that of the XRD patterns of the starting cellulose (Fig. 4).…”

Transfer Hydrogenation of Fatty Acids on Cu/ZrO2: Demystifying the Role of Carrier Structure and Metal–Support Interface

“…In addition to the ZrO 2 crystal form, the Cu–ZrO 2 interface also plays an important role in the catalytic hydrogenation of CO 2 to methanol. − Moreover, metal–support interfaces with other monoliths (CeO 2 , Al 2 O 3 , TiO 2 , Fe 2 O 3 , etc.) as supports have also been widely reported as an important feature that can be reasonably designed to enhance the catalytic activity. − The effect of support crystals, however, has not yet been reported for fatty acid hydrogenation. With the renewed impetus for this, we explore the influence of the support structure and the metal–support interfaces on the in situ hydrogenation of fatty acid.…”

Synthesis of novel hybrid mesoporous gold iron oxide nanoconstructs for enhanced catalytic reduction and remediation of toxic organic pollutants

“…Both the presence of a mesoporous structure in the support along with a mixed surface phase of Si and Fe oxides, seem to be key parameters, providing improved Au dispersion and higher contact surface area between the conned AuNPs within and/or at the exterior surface of the porous nanostructured support, in accordance with earlier observation. 29 To determine the magnetic characteristics of the Au-IO samples, eld-dependent magnetization (M-H) [20][21][22] of the asprepared mesostructures at 298 K were recorded (Fig. S3 †).…”