An active, selective, and stable manganese oxide-supported atomic Pd catalyst for aerobic oxidation of 5-hydroxymethylfurfural

Here we report for the first time a Pd-MnO₂ catalyst with a single-atom feature that can convert 5-hydroxylmethyfurfural (HMF) into the important bioplastic building block 2,5-furandicarboxylic acid (FDCA) with a high yield of 88% in aqueous solution using O₂ as an oxidant at ambient pressure. Pd-MnO₂ shows higher activity in the productivity of FDCA (100.91 mmol h^-1 g_Pd^-1) than its Pd nanoparticle counterpart (45.57 mmol h^-1 g_Pd^-1) and state-of-the-art Pd-based catalysts. Pd-MnO₂ displays promising recyclability with no degradation after five catalytic runs. Experimental and theoretical results suggest that the single-atom Pd sites that have enhanced binding affinity to HMF and their surrounding sites on the MnO₂ support work synergistically toward HMF oxidation.