Oxygen Vacancy Shell Coupled Pt Clusters Engineering for Sunlight Driven Selective Decarboxylation of Amino Acids

Solar-driven photocatalytic decarboxylation of amino acids is promising for the production of bio-based amines to address intensive energy consumption and overmuch CO₂ emissions in conventional thermo-catalytic process. In this work, we design a new heterogeneous photocatalyst with a rich oxygen vacancy (V_O) shell and Pt nanoclusters (Pt NCs) in TiO_2. The results unveil a strong interaction between the amorphous V_O-shell layer and Pt NCs in the engineered Pt/TiO₂@V_O-shell catalyst, leading to a prolonged lifetime from 0.79 to 1.12 ns. In the photocatalytic decarboxylation of L-lysine, Pt/TiO₂@V_O-shell exhibited a cadaverine selectivity of 70.2% and productivity of 154.5 mM/g, which is 14 and 111 times higher than that of TiO₂@V_O-shell. Notably, under sunlight irradiation of 1 h, the selectivity further increased to 73.5%. In addition, for other amino acids containing aliphatic side chains, the selectivity toward the corresponding amines exceeded 50%. Mechanistic study shows that positively charged V_Os facilitate the adsorption and activation of L-lysine via forming a bidentate bridging to produce alkyl radicals, while Pt NCs significantly promote the formation of hydrogen-rich surface of TiO₂ to give a high selectivity of cadaverine. This work offers a novel design strategy of catalysts for bridging a sustainable solar energy utilization and high-valued chemical synthesis.