Solid Base Bi₂₄O₃₁Br₁₀(OH)_δ with Active Lattice Oxygen for the Efficient Photo‐Oxidation of Primary Alcohols to Aldehydes

Abstract

The selective oxidation of primary alcohols to aldehydes by O₂ instead of stoichiometric oxidants (for example, Mn^VII , Cr^VI , and Os^IV ) is an important but challenging process. Most heterogeneous catalytic systems (thermal and photocatalysis) require noble metals or harsh reaction conditions. Here we show that the Bi₂₄ O₃₁ Br₁₀ (OH)_δ photocatalyst is very efficient in the selective oxidation of a series of aliphatic (carbon chain from C₁ to C₁₀ ) and aromatic alcohols to their corresponding aldehydes/ketones under visible-light irradiation in air at room temperature, which would be challenging for conventional thermal and light-driven processes. High quantum efficiencies (71 % and 55 % under 410 and 450 nm irradiation) are reached in a representative reaction, the oxidation of isopropanol. We propose that the outstanding performance of the Bi₂₄ O₃₁ Br₁₀ (OH)_δ photocatalyst is associated with basic surface sites and active lattice oxygen that boost the dehydrogenation step in the photo-oxidation of alcohols.