Structural Heredity in Catalysis: CO₂ Self‐Selective CeO₂ Nanocrystals for Efficient Photothermal CO₂ Hydrogenation to Methane

Abstract

The chemical inertness of CO₂ molecules makes their adsorption and activation on a catalyst surface one of the key challenges in recycling CO₂ into chemical fuels. However, the traditional template synthesis and chemical modification strategies used to tackle this problem face severe structural collapse and modifier deactivation issues during the often-needed post-processing procedure. Herein, a CO₂ self-selective hydrothermal growth strategy is proposed for the synthesis of CeO₂ octahedral nanocrystals that participate in strong physicochemical interactions with CO₂ molecules. The intense affinity for CO₂ molecules persists during successive high-temperature treatments required for Ni deposition. This demonstrates the excellent structural heredity of the CO₂ self-selective CeO₂ nanocrystals, which leads to an outstanding photothermal CH₄ productivity exceeding 9 mmol h^-1 m_cat ^-2 and an impressive selectivity of >99%. The excellent performance is correlated with the abundant oxygen vacancies and hydroxyl species on the CeO₂ surface, which create many frustrated Lewis-pair active sites, and the strong interaction between Ni and CeO₂ that promotes the dissociation of H₂ molecules and the spillover of H atoms, thereby greatly benefitting the photothermal CO₂ methanation reaction. This self-selective hydrothermal growth strategy represents a new pathway for the development of effective catalysts for targeted chemical reactions.