Customizable Quinary FeCoNiCuAl-Based High-Entropy Alloy Nanoparticles Supported on 3D-Printed Monolith for CO2 Hydrogenation

This Letter investigates the synthesis of amorphous high-entropy alloy (HEA) catalysts via non-thermal-shock microwave irradiation. As a proof-of-concept, we synthesized a quinary FeCoNiCuAl HEA with dual-phase BCC and FCC facets. Introducing a 3D-printed Ti64 monolith support has proven the catalyst's longevity during 1440 min time-on-stream and enhanced mass transfer. With an ultralow loading of ∼3 wt % HEA coated on the monolith, ∼100% of CH4 selectivity and ∼0.06 mol CH4 gcat–1 h–1 were attained, demonstrating the remarkable performance of HEA toward C–O cleavage. Overall, this work features advanced manufacturing adoption in roll-to-roll nanoscale materials for industrial-scale methanation.