Photoredox Cascade Catalysis for Hydrogen Production With Wacker Oxidation of Olefin Gases

Solar‐light‐driven photocatalytic coproduction of hydrogen (H 2 ) and valuable organic compounds is a promising technique for realizing sustainable carbon neutral society. In this work, we fabricate a new dual‐product photocatalytic system for the coproduction of H 2 and acetaldehyde/acetone by combining a dual Ru (II) dye‐sensitized Pt‐cocatalyst‐loaded TiO 2 nanoparticles photocatalyst with a Pd(II)‐acetate/9‐azanoradamantane N‐oxyl (nor‐AZADO • ) double‐mediatory Wacker oxidation catalytic system. This photoredox cascade catalytic system successfully converts gaseous ethylene/propylene substrates into H 2 and acetaldehyde/acetone under blue‐light irradiation owing to the electron mediation of nor‐AZADO • between the two (photo)catalytic cycles. The maximum turnover number per one photosensitizer and apparent quantum yield for the initial 1 h of irradiation in the presence of 5.0 vol% ethylene gas are estimated to be 1533 and 1.23%, respectively. These findings open a new avenue for simultaneously supplying clean energy resources, H 2 and organic valuables via oxidative organic transformations.