Pt nanoparticles supported on porous sheath TiO2 wrapped carbon nanotubes for selective glycerol electro-oxidation into tartronate†

Abstract

Developing high performance catalytic materials for the electro-oxidation of glycerol into specific value-added products is essential for glycerol valorization. Herein, we used the sol–gel method to coat the TiO₂ layer with adjustable thickness on the surface of carbon nanotubes (CNTs), obtaining a unique morphology of porous sheath TiO₂ wrapped CNTs (TiO₂/CNTs). Subsequently, Pt nanoparticles were loaded onto TiO₂/CNTs using the ethylene glycol reduction method. The prepared Pt–TiO₂/CNTs catalyst achieves a glycerol conversion near 100% at 0.8 V vs. RHE and 60 °C for 10 h. Notably, the selectivity of tartronate reaches 52.5% after 24 h. Characterization results reveal that the dispersed Pt nanoparticles are embedded into the holes of the TiO₂ porous sheath, fabricating abundant Pt–TiO₂–CNT interface structures. The infusion of TiO₂ shifts the center of the d-band upwards, and enhances the adsorption of the glycerate intermediate on Pt particles, which facilitates the further oxidation of glycerate to tartronate. This simple and efficient morphology control method provides a new strategy for glycerol valorization via electrocatalysis.