Direct Photocatalytic Conversion of Ethylene and Water Into Butanol via C─C Coupling and Hydroxylation

ABSTRACT Direct photocatalytic upgrading of olefins into long‐chain oxygenates using water as the sole oxygen and hydrogen source is highly attractive, yet remains challenging due to the difficulty of integrating intermolecular C─C coupling with selective hydroxylation. Herein, we report a photocatalytic pathway for the direct synthesis of n ‐butanol from ethylene and water over an in situ‐constructed Pt@Cu core–shell cocatalyst supported on TiO 2 . Under illumination, water is dissociated to generate surface *H and *OH species, which are synchronously incorporated into two activated ethylene molecules, while the remaining carbon centers undergo intermolecular C─C coupling to construct the C 4 backbone, enabling one‐step formation of n ‐butanol. The Pt core promotes directional electron extraction from TiO 2 and continuously enriches the surrounding Cu shell with electrons, thereby facilitating both ethylene activation and water dissociation. Meanwhile, dissolved Cu 2+ dynamically regulates the surface Cu redox state and preserves a Cu(I)‐rich active surface during photocatalysis. As a result, the Pt@Cu core–shell catalyst in Cu 2+ solution achieves a C 4 oxygenate production rate of 749.9 µmol g −1 h −1 with selectivity of 63.3%. This work establishes a photocatalytic strategy integrating C─C coupling and hydroxylation for solar‐driven synthesis of long‐chain oxygenates from olefins and water.