Induction Heating in Nanoparticle Impregnated Zeolite

Abstract

The ultra-stable Y (H-USY) zeolite is used as catalyst for the conversion of plastic feedstocks into high added value products through catalytic cracking technologies. However, the energy requirements associated with these processes are still high. On the other hand, induction heating by magnetic nanoparticles has been exploited for different applications such as cancer treatment by magnetic hyperthermia, improving of water electrolysis and many other heterogeneous catalytic processes. In this work, the heating efficiency of γ-Fe2O3 nanoparticle impregnated zeolites is investigated in order to determine the potential application of this system in catalytic reactions promoted by acid catalyst centers under inductive heating. The γ-Fe2O3 nanoparticle impregnated zeolite has been investigated by X-ray diffraction, electron microscopy, ammonia temperature program desorption (NH3-TPD), H2 absorption, thermogravimetry and dc and ac-magnetometry. It is observed that the diffusion of the magnetic nanoparticles in the pores of the zeolite is possible due to a combined micro and mesoporous structure and, even when fixed in a solid matrix, they are capable of releasing heat as efficiently as in a colloidal suspension. This opens up the possibility of exploring the application at higher temperatures.

Local Induction Heating Capabilities of Zeolites Charged with Metal and Oxide MNPs for Application in HDPE Hydrocracking: A Proof of Concept

“…A temperature increase about 75 °C in 800 s is observed for the γ-Fe 2 O 3 -impregnated system and 70 °C for the Ni–γ-Fe 2 O 3 one. The results obtained for the γ-Fe 2 O 3 -impregnated zeolite were quite similar to those referred to in a previous publication [ 36 ].…”

“…The incorporation of a Ni metal source with a zeolite material is a very common procedure in the literature, resulting generally in well-dispersed Ni particles in the supports [ 38 ]. Nevertheless, the incorporation of γ -Fe 2 O 3 in zeolite is a less studied topic [ 36 ]. Figure 1 a displays TEM images of the nanoparticles along with their size distribution fitted to a lognormal distribution; the inset shows the histogram of around 200 nanoparticles exhibiting a mean particle size of d = 11.7 nm and a polydispersity degree (standard deviation/mean size) σ = 0.2, as expected [ 37 ].…”

“…Since hydrocracking reactions are performed in a reductive atmosphere, it was also found important to evaluate the stability of mono- and co-impregnated zeolites under these conditions. In a previous study [ 36 ] on the stability of parent γ-Fe 2 O 3 MNPs and γ-Fe 2 O 3 MNPs impregnated in H-USY(40) zeolite under hydrogen atmosphere, it was found that the γ-Fe 2 O 3 nanoparticles exhibited two distinct mass losses: one at 344–444 °C and the other at 444–634 °C, corresponding respectively, to the transformation of γ-Fe 2 O 3 to Fe 3 O 4 and its subsequent reduction to metallic Fe. In turn, when γ-Fe 2 O 3 was impregnated in H-USY(40) zeolite, a continuous reduction pattern was observed.…”

“…In order to determine the potential application of γ-Fe 2 O 3 nanoparticle-impregnated H-USY zeolites for catalytic reactions promoted by acid catalyst under electromagnetic fields, their heating efficiency was previously investigated [ 36 ].…”

“…Due to the difficulty of stabilizing metallic MNPs, most of the literature refers to their oxides, alloys, or functionalized forms [29][30][31][32][33][34]. In order to determine the potential application of γ-Fe2O3 nanoparticle-impregnated H-USY zeolites for catalytic reactions promoted by acid catalyst under electromagnetic fields, their heating efficiency was previously investigated [36].…”