Ni ^δ+ Atoms Anchored In Situ on Ultrathin Ni‐Phyllosilicate Nanosheet Ensure High‐Efficient CO ₂ Reduction into CO at Moderate‐Low Temperature

Abstract Ni‐based catalysts are considered to be promising candidates for moderate‐low temperature (200−400 °C) reverse water‐gas shift (MLT‐RWGS) as an important CO ₂ reduction pathway. However, their high activation properties for CO inevitably lead to severe methanation at high CO ₂ conversion, creating an activity‐selectivity trade‐off and unsatisfactory CO yields. Here, a novel supported Ni‐based catalyst is deveolped, consisting of abundant Ni ^δ+ atoms anchored in situ on ultrathin Ni‐phyllosilicate nanosheet (a‐Ni ^δ+ −PSNS(400), 0< δ ≤1). The a‐Ni ^δ+ −PSNS(400) break activity‐selectivity trade‐off and achieve high CO selectivity (92%) toward at a formation rate of 21.0 mmol _CO h ⁻¹ gcat ⁻¹ , outdistancing those of all prevailing Ni‐based catalysts for MLT‐RWGS. Such catalytic performance is attributed to unique geometric/electronic effects of a‐Ni ^δ+ −PSNS(400), i.e., exposed monodisperse Ni ^δ+ atoms with low electron density on ultrathin Ni‐phyllosilicate nanosheet. The ultrathin nanosheet enables anchored Ni ^δ+ atoms to fully expose and disperse, boosting atom‐utilization efficiency and atom‐synergistic effects, endowing them with high catalytic activity; while low electron density of Ni ^δ+ atoms extremely weakens their chemical adsorption of CO, preventing further CO hydrogenation into CH ₄ , which ensures their high CO selectivity. This work provides new insights into the design of active microstructures of high‐performance Ni‐based catalysts for synchronous high activity‐selectivity.