Construction of electron transport channels and oxygen adsorption sites to modulate reactive oxygen species for photocatalytic selective oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran
Photocatalytic oxidation is an attractive approach for biomass valorization, but uncontrollable reactive oxygen species (ROS) inevitably initiates over-oxidation of target product, leading to low selectivity. Here we report that combining MnO 2 , WO 3 with carbon nitride (CN) enables the construction of photocatalyst with electron transport channels and oxygen adsorption sites. Owing to the rapid transfer of photo-generated electrons to adsorbed O 2 , CN-WO 3 @MnO 2 exhibited 12.5 and 0.18 times higher 1 O 2 and ∙O 2 - generation capacity than CN-WO 3 with 92.8% lower ∙OH generation capacity, respectively. With the synergistic effect of ∙O 2 - and 1 O 2 , 2,5-diformylfuran (DFF) selectivity up to 79.6% at high 5-hydroxymethylfurfural (HMF) conversion (77.6%) was attained. Both experimental results and density functional theory calculations indicate that the construction of electron transport channels and oxygen adsorption sites can deliberately modulate the generation of ROS with desired oxidation ability, thus facilitating the efficient and selective oxidation of HMF into DFF. • The oxidation of HMF to DFF is achieved by the synergistic effect of ∙O 2 - and 1 O 2 . • Efficient electron transport channels and oxygen adsorption sites was constructed. • The catalyst exhibited DFF yield of 61.8% with selectivity up to 79.6%.