Pt-N catalytic centres concisely enhance interfacial charge transfer in amines functionalized Pt@MOFs for selective conversion of CO2 to CH4

[Display omitted] Improving ligand-to-active metal charge transfer (LAMCT) by finely tuning the organic ligand is a decisive strategy to enhance charge transfer in metal organic frameworks (MOFs)-based catalysts. However, in most MOFs loaded with active metal catalysts, electron transmission encounters massive obstacle at the interface between the two constituents owing to poor LAMCT. Herein, amines (–NH2) functionalized MOFs (NH2-MIL-101(Cr)) encapsulated active metal Pt nanoclusters (NCs) catalysts are synthesized by the polyol reduction method and utilized for the photoreduction of CO2. Surprisingly, the introduction of –NH2 (electron donating) groups within the matrix of MIL-101(Cr) improved the electron migration through the LAMCT process, fostering a synergistic interaction with Pt. The combined experimental analysis exposed the high number of metallic Pt (Pt0) in Pt@NH2-MIL-101(Cr) catalyst through seamless electron shuttling from N of –NH2 group to excited Pt generating versatile hybrid Pt-N catalytic centres. Consequently, these versatile hybrid catalytic centres act as electro-nucleophilic centres, which enable the efficient and selective conversion of CO bond in CO2 to harvest CH4 (131.0 µmol.g−1) and maintain excellent stability and selectivity for consecutive five rounds, superior to Pt@MIL-101(Cr) and most reported catalysts. Our study verified that the precise tuning of organic ligands in MOFs immensely improves the surface-active centres, electron migration, and catalytic selectivity of the excited Pt NCs catalysts encaged inside MOFs through an improved LAMCT pathway.