Continuous Flow Preparation of Iron Oxide Nanoparticles Supported on Porous Silicates

Abstract

A simple, innovative, and efficient continuous flow methodology for the direct preparation of supported nanoparticles on porous materials by using metal precursor solution flowing through heated packed‐bed reactors containing the support material has been developed. The effects of the flow rate of the precursor solution, temperature, and nature of the support material and metal loading have been investigated. Results indicated that optimum conditions comprised short residence times (with typical flow rates of 0.5 mL min−1 and below) under mild heating (100 °C) to achieve optimum materials in terms of nanoparticle size and structure and catalytic activity. The support was found to have a remarkable effect on both loading and distribution and agglomeration of nanoparticles in the system, with a previously reported Fe/Al synergy also observed in the prepared nanomaterials, which led to optimum results.

Microwave-Assisted Conversion of Levulinic Acid to γ-Valerolactone Using Low-Loaded Supported Iron Oxide Nanoparticles on Porous Silicates

“…Textural properties of synthesized materials in this work are summarized in Table 1 ), in good agreement with typical characteristics of mesoporous SBA-15 materials. The incorporation of Fe in the systems did not have any significant effect on the textural properties of supported materials in terms of surface area, pore size and volume, in good agreement with previously observed surface deposition of Fe species under continuous flow preparation [33]. Fe loading was found to be less than 1 wt%, with a slightly higher loading observed for FeAlCF with respect to FeZrCF.…”

“…Fe loading was found to be less than 1 wt%, with a slightly higher loading observed for FeAlCF with respect to FeZrCF. No significant differences were obtained between ICP and EDX analysis, which correlated well with previous synthesized catalytic nanomaterials under flow conditions [33]. Both Pd systems (PdAlCF and PdAlSBA-BM) contained ca.…”

“…Inspired by our previous work on the hydrogenation of LA using Cu-containing silica materials, we designed a supported iron oxide catalyst on porous silicates based on our previous report [30,33]. We applied a simple, innovative, and efficient continuous flow methodology for the deposition of iron oxide nanoparticles on porous materials.…”

“…Al-SBA-15 materials (Si/Al = 20 ratio) were synthesized according to a previously reported protocol [33]. A solution (300 mL) of hydrochloric acid at pH = 1.5 was prepared, then 8.07 g of the surfactant (poly (ethylene-glycol)-block (P123 Aldrich) was added to this solution.…”

“…The continuous flow deposition of iron oxide nanoparticles on Al-SBA-15 was performed under a series of conditions using a recently reported, innovative, continuous flow setup depicted in Figure 1 [33]. A stainless-steel reactor (1.2 cm 3 volume) was packed with Al-SBA-15 support (typically 0.5 g), set between two plugs of quartz wool to prevent the solid support to move in the reactor upon pumping in the flow of the solution of the metal precursor.…”