General and Scalable Synthesis of Mesoporous 2D MZrO ₂ (M = Co, Mn, Ni, Cu, Fe) Nanocatalysts by Amorphous‐to‐Crystalline Transformation

Abstract In modern heterogeneous catalysis, it remains highly challenging to create stable, low‐cost, mesoporous 2D photo‐/electro‐catalysts that carry atomically dispersed active sites. In this work, a general shape‐preserving amorphous‐to‐crystalline transformation (ACT) strategy is developed to dope various transition metal (TM) heteroatoms in ZrO ₂ , which enabled the scalable synthesis of TMs/oxide with a mesoporous 2D structure and rich defects. During the ACT process, the amorphous MZrO ₂ nanoparticles (M = Fe, Ni, Cu, Co, Mn) are deposited within a confined space created by the NaCl template, and they transform to crystalline 2D ACT‐MZrO ₂ nanosheets in a shape‐preserving manner. The interconnected crystalline ACT‐MZrO ₂ nanoparticles thus inherit the same structure as the original MZrO ₂ precursor. Owing to its rich active sites on the surface and abundant oxygen vacancies (OVs), ACT‐CoZrO ₂ gives superior performance in catalyzing the CO ₂ ‐to‐syngas conversion as demonstrated by experiments and theoretical calculations. The ACT chemistry opens a general route for the scalable synthesis of advanced catalysts with precise microstructure by reconciliating the control of crystalline morphologies and the dispersion of heteroatoms.