Pt-O/Pt active sites and electrocatalytic properties for methanol oxidation enhanced dually by anatase/rutile TiO2 and BiOx

Abstract

Understanding the details of how Pt-O/Pt active sites are boosted is essential for many catalytic reactions. Herein, different anatase/rutile (A/R) phase ratios of TiO2 nanoparticles (NPs) prepared by controlling calcination temperature (T), and irreversibly adsorbed Bi(III) are employed to dually improve the Pt-O/Pt active sites and their electrocatalytic activities. It is found that a T-dependent concave improvement trend is obtained on Pt/TiO2-T for the Pt-O/Pt active sites and electrocatalytic methanol oxidation rate. In the simultaneous presence of TiO2-T and BiOx, the electron-rich R(110) facet of TiO2-950 can promote the formation of bimetallic Bi-Pt sites, and the oxygen-acceptable Bi(III) is favorite for the electrochemical assembly of {Bi-Ox-Pt} active sites on the R(110) facet, further achieving a remarkable increase of 19.7-fold and 4.5-fold for the Pt-O/Pt active sites and electrocatalytic activity towards methanol oxidation compared with the case of bare Pt electrodes, respectively. The relationship between the Pt-O/Pt active sites and electrocatalytic properties is demonstrated, and the complete oxidation mechanism of methanol is proposed on BiOx-[Pt-TiO2-950] with reliable long-term durability. This study shows a new dually tuning strategy to maximize the utilization efficiency and anti-deactivated ability of Pt-based catalysts by TiO2-T and BiOx.