Low-Temperature Hydrogen Production via Water Conversion on Pt/TiO₂

Abstract

Pt-supported TiO2 catalysts have proved to be good catalysts for efficient hydrogen (H2) production from photocatalytic water (H2O) splitting and water–gas shift reactions. However, their origin for efficient H2O conversion remains poorly understood. Here, we report a systematic study of low-temperature H2 formation via H2O conversion on Pt-deposited rutile-TiO2(110) surfaces by means of spectroscopic and microscopic techniques in combination with first-principles calculations. We show that the low-temperature H2 formation can occur facilely at ∼200 K via H2O conversion on the Pt clusters/rutile-TiO2(110) surfaces, which is initiated by H2O dissociation at the surface defects, metal–oxide interfaces, and probably regular Ti4+ sites. More importantly, H2O-assisted multistep H atom diffusion plays a crucial role for transferring H atoms toward Pt clusters, resulting in efficient H2 evolution. These results enrich the understanding of H2 formation via H2O conversion on Pt/TiO2 catalysts, which is helpful for understanding this reaction on other metal–oxide catalysts.