# Silica-supported Pt(0) single-atom catalyst chemisorbing hydrogen but converting to Pt(iv) by ambient oxygen

## TL;DR

This study shows that platinum single atoms on silica can hold hydrogen but don't act as catalysts and easily turn into a different form when exposed to oxygen.

## Contribution

The discovery that Pt(0) single atoms on silica are oxidized to Pt(iv) by ambient oxygen, challenging their use in oxidation catalysis.

## Key findings

- Pt(0) single atoms on silica chemisorb 2.0 hydrogen atoms per platinum atom.
- Pt(0) single atoms on silica lack catalytic activity for olefin hydrogenation.
- Exposure to ambient oxygen converts Pt(0) to Pt(iv), affecting catalytic properties.

## Abstract

We confirmed the stabilization of Pt(0) single atoms on porous silica using electron microscopy and X-ray absorption. The Pt/silica exhibited strong chemisorption of 2.0H/Pt, but no catalytic activity was observed for olefin hydrogenation. The Pt(0) state was changed to Pt(iv) by ambient O2, which led to doubt about oxidation catalytic abilities as Pt(0).

Pt(0) single atoms on porous silica show strong hydrogen chemisorption (2.0H/Pt) but no olefin hydrogenation activity, and are readily oxidized to Pt(iv) upon exposure to oxygen.