# Activation of propane on Ag–PdO(101) model surfaces

## TL;DR

Adding silver to a palladium oxide surface lowers the temperature needed to oxidize propane, making the reaction more efficient.

## Contribution

The study shows that Ag incorporation modifies reaction energetics and enables better selectivity in propane oxidation.

## Key findings

- Ag incorporation induces CO2 desorption at lower temperatures (330 K) compared to pristine PdO(101) (475 K).
- Low-temperature activity correlates with Ag coverage, but overall CO2 production decreases.
- Activation energy for C–H bond activation is reduced by 46 kJ/mol at the Ag–PdO(101) interface.

## Abstract

Oxidation of alkanes remains a central challenge in catalysis due to the high activation barriers of C–H bonds and the thermodynamic favorability of complete oxidation. Palladium oxide (PdO), particularly its (101) facet, is known for its high reactivity in alkane oxidation, which is attributed to its coordinatively unsaturated palladium (Pd) and O atoms. In this study, we investigate the effect of silver (Ag) incorporation on the oxidation behavior of propane over PdO(101) using temperature-programmed reaction spectroscopy (TPRS) under controlled conditions. While pristine PdO(101) exhibits complete oxidation of propane with CO2 and H2O desorption at high temperatures (approximately 475 K), Ag incorporation induces a new CO2 desorption peak at significantly lower temperatures (approximately 330 K). This shift is attributed to the formation of new active sites at the Ag–PdO(101) interface. Quantitative analysis reveals that low-temperature activity correlates with Ag coverage, while overall CO2 production decreases, suggesting a redistribution of reactivity rather than an increase in active surface area. Activation energy estimations using the Redhead method confirm that C–H bond activation becomes more facile at the interface, with a 46 kJ/mol reduction compared to pristine PdO(101). These findings demonstrate that incorporating a less reactive metal such as Ag into PdO surfaces not only modifies the reaction energetics but also enables the design of bimetallic catalysts with improved selectivity for partial oxidation reactions.