# Selective Low-Temperature Oxidative Dehydrogenation of Propane over Alumina-Supported Copper Nanoparticles with O2 and CO2 as Oxidants

## TL;DR

This paper studies how copper nanoparticles on different alumina supports affect propane conversion to propylene at low temperatures using oxygen or carbon dioxide.

## Contribution

The study reveals that copper nanoparticles on nano-alumina support achieve higher propylene selectivity and stability with CO2 as an oxidant.

## Key findings

- Cu/nanoAl2O3 achieves 35–48% propylene selectivity at 250–300 °C with O2.
- Using CO2 as oxidant boosts propylene selectivity to 100% for Cu/nanoAl2O3.
- Copper particle size differences explain performance variations between the two catalysts.

## Abstract

This study reports on the performance of alumina-supported copper-based catalysts in the oxidative dehydrogenation of propane, with copper dispersed on two distinct commercial aluminium oxide supports made of micro- and nanosized alumina, respectively. The activity and selectivity of the two catalysts was investigated at temperatures between 250 and 550 °C. At a propane-to-O2 ratio of 1:1, Cu/nanoAl2O3 achieves propylene selectivity of 35–48% at low temperatures (250–300 °C), while Cu/Al2O3 only exhibits activity starting at 350 °C with about 40% propylene selectivity. Altering the propylene-to-oxygen ratio to 3:1 enhances selectivity towards propylene in both catalysts, up to about 64% on Cu/Al2O3 at temperatures of 250–350 °C. The switch to the mild oxidant CO2 boosts propylene selectivity to 100%. In case of Cu/nanoAl2O3, the rate of propylene formation doubles that of the obtained with O2 used as oxidant. While with CO2 the Cu/nanoAl2O3 catalyst retains 100% propylene selectivity up to 500 °C, on the less active Cu/Al2O3 cracking sets off already at 400 °C. The different size of copper particles in the two catalysts is seen as a primary factor determining the observed differences in the performance of the studied catalysts.