Reductive Transformation of Layered‐Double‐Hydroxide Nanosheets to Fe‐Based Heterostructures for Efficient Visible‐Light Photocatalytic Hydrogenation of CO

Abstract Conversion of syngas (CO, H 2 ) to hydrocarbons, commonly known as the Fischer–Tropsch (FT) synthesis, represents a fundamental pillar in today's chemical industry and is typically carried out under technically demanding conditions (1–3 MPa, 300–400 °C). Photocatalysis using sunlight offers an alternative and potentially more sustainable approach for the transformation of small molecules (H 2 O, CO, CO 2 , N 2 , etc.) to high‐valuable products, including hydrocarbons. Herein, a novel series of Fe‐based heterostructured photocatalysts (Fe‐ x ) is successfully fabricated via H 2 reduction of ZnFeAl‐layered double hydroxide (LDH) nanosheets at temperatures ( x ) in the range 300–650 °C. At a reduction temperature of 500 °C, the heterostructured photocatalyst formed (Fe‐500) consists of Fe 0 and FeO x nanoparticles supported by ZnO and amorphous Al 2 O 3 . Fe‐500 demonstrates remarkable CO hydrogenation performance with very high initial selectivities toward hydrocarbons (89%) and especially light olefins (42%), and a very low selectivity towards CO 2 (11%). The intimate and abundant interfacial contacts between metallic Fe 0 and FeO x in the Fe‐500 photocatalyst underpins its outstanding photocatalytic performance. The photocatalytic production of high‐value light olefins with suppressed CO 2 selectivity from CO hydrogenation is demonstrated here.