Photocatalytic methanol dehydrogenation promoted synergistically by atomically dispersed Pd and clustered Pd

TL;DR

This study demonstrates that combining atomically dispersed Pd and Pd clusters on CdS significantly enhances photocatalytic methanol dehydrogenation, achieving high efficiency through synergistic effects.

Contribution

It reveals the synergistic effect of supported Pd1 and Pd clusters on CdS, leading to improved photocatalytic activity for methanol dehydrogenation, which was previously overlooked.

Findings

Highest turnover frequency of 1.14 s-1 based on Pd content.

Achieved 87% apparent quantum yield at 452 nm.

Synergistic catalysis enhances hydrogen and formaldehyde production.

Abstract

Supported metal in the form of single atoms, clusters, and particles can individually or jointly affect the activity of supported heterogeneous catalysts. While the individual contribution of supported metal to the overall activity of supported photocatalysts has been identified, the joint activity of mixed metal species is overlooked because of their different photoelectric properties. Here, atomically dispersed Pd (Pd1) and Pd clusters are loaded onto CdS, serving as oxidation and reduction sites, respectively, for methanol dehydrogenation. The Pd1 substitutes Cd2+, forming hole-trapping states for methanol oxidation and assisting the dispersion of photo-deposited Pd clusters. Therefore, methanol dehydrogenation on CdS with supported Pd1 and Pd clusters exhibits the highest turnover frequency of 1.14 s-1 based on Pd content, and affords H2 and HCHO with a similar apparent quantum yield of 87 +/- 1% at 452 nm under optimized reaction conditions. This work highlights the synergistic catalysis of supported metal for improved photocatalytic activity.