Tandem catalysis induced by hollow PdO: highly efficient H2 generation coupled with organic dye degradation via sodium formate reforming

Abstract

High-quality crystalline PdO nanoparticles with Kirkendall nanovoids uniformly supported on titanate nanotubes (kv-PdO/TiNTs) are shown to be robust catalysts toward low temperature formate reforming into CO_x-free H₂ as well as sequential organic dye degradation under ambient conditions. The maximum H₂ evolution reaction rate for kv-PdO/TiNTs catalysts is measured to be in the magnitude of 6.5 mol g⁻¹ h⁻¹ at room temperature (∼25 °C), and the corresponding initial turnover frequency (TOF) is as high as 2601.6 h⁻¹. More importantly, for the first time we find that the H₂ production system is highly efficient for subsequent organic dye degradation without the addition of external energy, such as light, electricity and heat, or the addition of any artificial oxidants, e.g., H₂O₂. It is speculated that the active oxygen-centered species generated in the dehydrogenation catalytic system and the pre-reduction process induced by free hydrogen radicals play important roles in organic dye treatment. Thus, a unique tandem catalytic system by coupling hydrogen production with organic dye degradation is presented.