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

Pt-supported TiO 2 catalysts have proved to be good catalysts for efficient hydrogen (H 2 ) production from photocatalytic water (H 2 O) splitting and water–gas shift reactions. However, their origin for efficient H 2 O conversion remains poorly understood. Here, we report a systematic study of low-temperature H 2 formation via H 2 O conversion on Pt-deposited rutile-TiO 2 (110) surfaces by means of spectroscopic and microscopic techniques in combination with first-principles calculations. We show that the low-temperature H 2 formation can occur facilely at ∼200 K via H 2 O conversion on the Pt clusters/rutile-TiO 2 (110) surfaces, which is initiated by H 2 O dissociation at the surface defects, metal–oxide interfaces, and probably regular Ti 4+ sites. More importantly, H 2 O-assisted multistep H atom diffusion plays a crucial role for transferring H atoms toward Pt clusters, resulting in efficient H 2 evolution. These results enrich the understanding of H 2 formation via H 2 O conversion on Pt/TiO 2 catalysts, which is helpful for understanding this reaction on other metal–oxide catalysts.