Promotional Effect of H2 Pretreatment on the CO PROX Performance of Pt1/Co3O4: A First-Principles-Based Microkinetic Analysis

Atomic Pt studded on cobalt oxide is a promising catalyst for CO preferential oxidation (PROX) dependent on its surface treatment. In this work, the CO PROX reaction mechanism on Co3O4 supported single Pt atom is investigated by a comprehensive first-principles based microkinetic analysis. It is found that as synthesized Pt-1/Co3O4 interface is poisoned by CO in a wide low temperature window, leading to its low reactivity. The CO poisoning effect can be effectively mitigated by a H-2 prereduction treatment, that exposes Co similar to Co dimer sites for a noncompetitive Langmuir-Hinshelhood mechanism. In addition, surface H atoms assist O-2 dissociation via twisting mechanism, avoiding the high barriers associated with direct O-2 dissociation path. Microkinetic analysis reveals that the promotion of H-assisted pathway on H(2 )treated sample helps improve the activity and selectivity at low temperatures.

Automated summary

This study investigates the mechanism of CO PROX reaction on Co3O4 supported single Pt atom through first-principles based microkinetic analysis. The research finds that H2 prereduction treatment effectively mitigates the CO poisoning effect and surface H atoms assist in improving the activity and selectivity at low temperatures.