Size-modulated Pt nanoparticles for low-temperature plasmon-enhanced hydrogen production from aqueous phase reforming of methanol

• A volcano-like reactivity trends was demonstrated for size-modulated Pt/Al 2 O 3. • Size modulation of Pt nanoparticles enhances its light absorption ability. • Electron-deficient Pt facilitates the adsorption and activation of methanol. • Light irradiation promotes the sequential water–gas shift reaction on Pt sites. Al 2 O 3 supported Pt nanoparticles photocatalyst enables efficient hydrogen production (115.2 μmol min −1 g cat −1 ) through aqueous phase reforming of methanol (APRM) reaction under light irradiation at low temperatures of 150 °C, which is 6 times higher than that of APRM reaction conducted in the dark. We demonstrate that the particle size of Pt nanoparticles greatly affected the light absorption ability, which is of great importance for light utilization of the photocatalyst. The medium particle size of Pt nanoparticles enables the lower electron density states, which is benefit for the dehydrogenation of methanol and the sequential water–gas shift (WGS) reaction and eventually promoted the photocatalytic performance for hydrogen production.