Fe@SiO₂@Ni: An Iron-Based Composite Material for Magnetically Induced Hydrogenation Reactions in Gas and Solution Phases

Recently, magnetically induced catalytic CO 2 hydrogenation has gained attention due to its high energy efficiency and better heat management of exothermic processes compared to thermal heating. Ferromagnetic nanoparticles combining heating and catalytic properties are shown to be efficient, but the complex synthesis procedure limits their potential as industrial products. In this work, commercially available iron (Fe) wool was chemically modified by a sol–gel coating of a silica (SiO 2 ) layer followed by nickel (Ni) particle deposition and employed as a catalyst for magnetically induced gas-phase CO 2 hydrogenation reaction. The composite material was thoroughly characterized by combined X-ray photoelectron spectroscopy (XPS), focused ion beam scanning electron microscopy (FIB-SEM), and magnetic and specific absorption rate (SAR) measurements as well as its catalytic activity. This material shows an enhanced catalytic activity (higher CO 2 conversion and CH 4 selectivity) compared to Ni-only-coated iron wool, which could be attributed to the stabilization of the composite catalyst. Adding a Siralox filler in the catalytic bed further improves CO 2 conversion, CH 4 selectivity, and catalyst stability. Furthermore, this composite catalyst is demonstrated to be active for solution-phase model hydrogenation and hydrodeoxygenation reactions, thus anticipating its potential for a broader range of catalytic applications in organic chemistry.