Redispersion of PdCu/AC sintered catalyst under CO-O2 atmosphere and mechanism study

Abstract

Loaded noble metal redispersion is an important way to solve catalyst sintering. However, how to redisperse at low temperatures or carbon-based noble catalysts is a difficult problem. In this paper, we report this phenomenon occurring on PdCu alloy catalysts, where small-sized PdCu alloys can be realized from sintered large-sized PdCu alloys on carbon supports in a CO/O2 atmosphere. The mechanism of redispersion is elucidated by XPS, TEM and DFT calculations. The main reason for the redispersion is the formation of the PdCuOx intermediate, which can easily migrate to the nearby catalyst surface and then be reduced to smaller PdCu alloy nanoparticles. This work provides a deeper understanding of the redispersion phenomenon and provides certain applications in industry.