Aqueous phase reforming of methanol for hydrogen production over highly-dispersed PtLa/CeO2 catalyst prepared by photochemical reduction method.

Hydrogen production by catalytic aqueous phase reforming (APR) of biomass oxygenated derivatives in relatively mild conditions is a promising way to produce hydrogen. In this work, Pt/CeO 2 -HT, Pt/La–CeO 2 -HT and PtLa/CeO 2 catalysts were synthesized by a novel photochemical reduction method and applied to the methanol APR. Extensive characterizations have proved that the mild catalyst preparation method gave it a high dispersion of Pt species and the addition of La modified the metal-support interaction. The results showed that La-modified Pt/La–CeO 2 -HT and PtLa/CeO 2 catalysts exhibited better catalytic performance than the Pt/CeO 2 -HT catalyst, among which the hydrogen yield was the highest for the surface La-modified PtLa/CeO 2 catalyst (177.7 mmol/g cat). This was mainly attributed to the surface modification of La resulted in a significant increase in the number of moderately strong basic sites and surface oxygen vacancies in the PtLa/CeO 2 catalyst. The enhancement of catalyst basicity effectively promoted the dissociation of H 2 O to produce hydroxyl groups, while a large number of surface oxygen vacancies provided more active sites for the adsorption and dissociation of H 2 O. And their synergistic behavior efficiently facilitated the water gas shift (WGS) reaction, resulting in a significant increase in hydrogen yield of methanol APR. Associated with the in situ DRIFTS analyzes and the results indicated by WGS reaction, possible promotion mechanism was proposed. [Display omitted] • Highly-dispersed APR catalysts were prepared by a novel photochemical reduction method. • The PtLa/CeO 2 catalyst exhibited the highest catalytic activity and H 2 yield (177.7 mmol/g cat). • Possible reaction mechanism of the synergistic effect on oxygen vacancies and basic sites is verified. [ABSTRACT FROM AUTHOR]