Highly Catalytic Selectivity for Hydrogen Peroxide Generation from Oxygen Reduction on Nd-Doped Bi4Ti3O12Nanosheets

Abstract

The electrochemical two-electron oxygen reduction reaction (2e–1ORR) is a promising route for renewable H2O2 generation as an alternative method to the anthraquinone process. The development of efficient and highly selective catalytic materials is a highly meaningful and challenging subject due to the strong competition from the traditional four-electron oxygen reduction reaction (4e–1ORR). Here, we synthesized bismuth titanate (Bi4Ti3O12) nanosheets as a type of new electrocatalyst for H2O2 generation from 2e–1ORR. The structure of the Bi4Ti3O12 nanosheets is characterized by high-resolution transmission electron microscopy (HRTEM) and X-ray techniques. The electrochemical measurements show that the obtained bismuth titanate (Bi4Ti3O12), especially the neodymium (Nd)-substituted Bi4Ti3O12, has high catalytic activity and selectivity for O2 to H2O2. For the ORR catalyzed by Bi4Ti3O12 nanosheets, 83–89% H2O2 selectivity can be achieved in a wide range of potentials, while Nd-substituted Bi4Ti3O12 nanosheets afford a higher selectivity of 93–95%. Moreover, in a two-chamber H-cell, H2O2 production of 208 mol kgcat–1 can be achieved at 0.36 V under the catalysis of Nd-substituted Bi4Ti3O12 for 1 h with a Faraday efficiency of 97.6%. The high O2-to-H2O2 catalytic performance could be ascribed to the large surface area and the abundant exposed active sites of the nanosheets.