Atomically Alloyed Fe–Co Catalyst Derived from a N-Coordinated Co Single-Atom Structure for CO<sub>2</sub> Hydrogenation
Sun-Mi Hwang, Seung Ju Han, Hae‐Gu Park, Hojeong Lee, Kwangjin An, Ki‐Won Jun, Seok Ki Kim
Abstract
We report a stable and efficient Fe–Co catalyst derived from N-coordinated Co single-atom carbon (FeK/Co–NC) for CO2 conversion to long-chain hydrocarbons with a C5+ selectivity of up to 42.4% at a conversion of 51.7% at 300 °C and 2.5 MPa. Its performance remained stable over a time-on-stream of 100 h. The FeK/Co–NC catalyst exhibited less methane selectivity (21.6%) than the coimpregnated FeCoK/NC catalyst (33.8%), which is attributed to the Co–NC support, efficiently inducing Fe–Co alloy formation by atomically supplying Co into Fe nanoparticles. The Fe–Co alloy of the FeK/Co–NC catalyst remained stable in both carburized and oxide forms during the reaction. Density functional theory suggests that Fe–Co mixed oxides accelerate oxygen removal during the reverse water–gas shift, whereas Fe–Co mixed carbides promote chain growth to suppress methane formation during Fischer–Tropsch synthesis. Our combined experimental and theoretical study demonstrates the promoting effect of the Fe–Co atomic alloy structure for CO2 hydrogenation.