Tuning ferrite nanoparticles for optimal inductive heating in thermal swing adsorption processes

Abstract

By enabling faster regeneration of adsorbents and minimizing heat losses, inductive heating is key to improving the efficiency, capacity and carbon neutrality of temperature swing adsorption systems. For successful implementation of inductive heating, access to performant and chemically robust susceptor materials is essential. Combining performance with chemical stability is however challenging and current magnetic susceptors typically only achieve one of these requirements. This report presents a strategy for the complete optimization of ferrite nanoparticles, yielding susceptors with superior inductive heating performance and excellent chemical robustness. Superparamagnetic nickel–zinc ferrite nanoparticles with optimized heating performance within the boundary conditions imposed by inductive heating swing adsorption applications are synthesised and their heating performance was experimentally evaluated and rationalised. Chemical composition as well as the calcination temperature at which ferrite precursors are converted into the susceptor materials are demonstrated to be critical for maximizing the heat response. Tuning chemical composition and calcination temperature enabled enhancement of the specific absorption rate of a Ni_(1−x)Zn_xFe₂O₄ ferrite system by one order of magnitude. Ni_0.6Zn_0.4Fe₂O₄ nanoparticles (Ø 78 nm) synthesized at 900 °C generate an outstanding specific absorption rate of 113.7 W g⁻¹ excited by a 135.7 Oe magnetic field alternating at 248 kHz. The optimization route is discussed and rationalized based on the identified induction heating mechanism.