Tuning the Composition of FeCo Nanoparticle Heating Agents for Magnetically Induced Catalysis

Abstract

Magnetic heating by nanoparticles has recently been successfully employed in heterogeneous catalysis. In such processes, the maximum temperature that can be reached depends on the Curie temperature (T c) of the heating material. Here, in order to extend the range of accessible temperatures and consequently the range of possible reactions, to those requiring high temperatures, we developed and fully characterized a series of FeCo nanoparticles containing different concentrations of cobalt, in order to tune their magnetic properties and Tc. Their efficiency is compared to that of iron carbide nanoparticles, which display a lower Tc. Specific Absorption Rate (SAR) measurements as a function of temperature, performed using a homemade pyrometer-based setup, clearly show that, although the heating power of iron carbide nanoparticles is higher at room temperature, it decreases more rapidly with temperature than that of iron cobalt nanoparticles, in agreement with their lower Tc. In a showcase, Fe 0.5 Co 0.5 nanoparticles allow, in addition to CO 2 hydrogenation, dry reforming of propane and methane, and dehydrogenation of propane, these reactions requiring temperatures of 350°C, 600°C and 700°C respectively. Furthermore, the use of Fe 0.5 Co 0.5 nanoparticles is less energy demanding, as it allows carrying out CO 2 hydrogenation at lower magnetic fields and at frequencies as low as 100 kHz. Dry reforming of methane and propane were carried out in the presence of a Ni nanoparticle-based catalyst whereas dehydrogenation of propane required as a catalyst PtSn nanoparticles synthesized through an organometallic route. Fe 0.5 Co 0.5 nanoparticles can therefore be used as universal heating agents allowing performing reactions up to ca. 700°C upon association with the appropriate catalyst.

Hydrodeoxygenation and hydrogenolysis of biomass-based materials using FeNi catalysts and magnetic induction

“…Thus, FeNi3 NPs which display low magnetocrystalline anisotropy, catalyze the CO2 hydrogenation at lower magnetic field than previously reported materials, e.g. FeC 35 and FeCo NPs, 43 thus improving the energy efficiency of the process. 48 Furthermore, FeNi3…”

“…32 More recently, magnetic heating has also been applied to activate catalytic reactions as it permits generating a rapid and localized rise of the temperature at the surface of the heating agents without the need to heat up the whole reactor. Several groups including ours, explored the magnetic activation of heterogeneous catalytic reactions in the gas phase such as the Fischer-Tropsch reaction, 33,34 CO2 hydrogenation, [35][36][37][38][39] methane reforming [40][41][42][43] or alkane dehydrogenation. 43 Magnetic heating has also been used in liquid phase reactions, but it was often limited to reactions taking place at moderate temperatures such as C-C coupling, 44 amide condensation, 45 and more recently hydrogenation of furfural.…”

Single-Crystalline Body Centered FeCo Nano-Octopods: From One-Pot Chemical Growth to a Complex 3D Magnetic Configuration

“…27 Their size, shape and chemical composition could be tuned by the experimental parameters (nature and concentration of ligands, precursor concentrations). 27,28 As prepared, these NPs exhibited saturation magnetization values comparable with the bulk one (Ms = 226 A.m².kg -1 ). 27,29 In this paper, we report the synthesis and the advanced magnetic characterization of FeCo nanooctopods.…”

A Guideline for Effectively Synthesizing and Characterizing Magnetic Nanoparticles for Advancing Nanobiotechnology: A Review

“…Elsewhere, Das et al reported on the enhanced heating efficiency of elongated magnetic nanoparticles using the AC field [139], where they showed the shape anisotropy induced by elongation is the key for tuning the heating efficiency of the magnetic nanoparticles. The requirement of a high heating generation rate for special applications, such as nanowarming of cryopreserved organs, the AC field technique became a strong technique for characterizing the magnetic nanowires, as they are capable to generate much higher heats granted to their shape anisotropy [137,153].…”