Ni-based catalysts derived from layered-double-hydroxide nanosheets for efficient photothermal CO₂ reduction under flow-type system

Photothermal CO₂ reduction is an efficient and sustainable catalytic path for CO₂ treatment. Here, we successfully fabricated a novel series of Ni-based catalysts (Ni-x) via H₂ reduction of NiAl-layered double hydroxide nanosheets at temperatures (x) ranging from 300 to 600 ℃. With the increase of the reduction temperature, the methane generation rate of the Ni-x catalyst for photothermal CO₂ hydrogenation gradually increased under ultraviolet-visible-infrared (UV–vis–IR) irradiation in a flow-type system. The Ni-600 catalyst showed a CO₂ conversion of 78.4%, offering a CH₄ production rate of 278.8 mmol·g^–1·h^–1, with near 100% selectivity and 100 h long-term stability. Detailed characterization analyses showed metallic Ni nanoparticles supported on amorphous alumina are the catalytically active phase for CO₂ methanation. This study provides a possibility for large-scale conversion and utilization of CO₂ from a sustainable perspective.