Low-temperature combustion of methane over graphene templated Co3O4 defective-nanoplates

Dian Gong,Gaofeng Zeng

doi:10.1038/s41598-021-92165-4

Abstract

Transition metal oxides are the potential catalysts to replace noble-metal based catalyst for the catalytic combustion of methane due to the tolerable reactivity and low cost. However, these catalysts are challenged by the low temperature reactivity. Herein, the surface defective Co3O4 nanoplates are realized through a facile co-precipitation and thermal reduction method with the association of GO. The resultant catalysts (CoGO50) demonstrate a superior low-temperature reactivity for the methane oxidation to CO2 and H2O in comparison with the common Co3O4 catalyst. The reliable stability of CoGO50 catalyst was proved by 80 h testing with intermittent feeding of water vapor. The experimental analysis demonstrates that the presence of a small amount of GO significantly affects the catalysts in surface valence state, active oxygen species and surface oxygen vacancies through reacting with the cobalt oxide as a reductant. Moreover, GO plays as 2D confine template to form smaller and thinner nanoplates. This work provides a facile method to control the surface properties of catalyst not only for Co3O4 based catalysts but also for wider solid catalysts.

Highlights

Transition metal oxides are the potential catalysts to replace noble-metal based catalyst for the catalytic combustion of methane due to the tolerable reactivity and low cost
We developed graphene oxide involved Co3O4 catalyst (CoGO) through a facile co-precipitation method
The transmission electron microscope (TEM) images of single nanoplate of Co3O4, CoGO50 and CoGO100 display that the thickness of CoGO50 is thinner than others, which may contribute to the confinement effect of GO flakes in the preparation (Fig. 1B,D,F)

Summary

Introduction

Transition metal oxides are the potential catalysts to replace noble-metal based catalyst for the catalytic combustion of methane due to the tolerable reactivity and low cost. Supported noble metal catalysts, such as Pt, Au, Rh and Pd, are widely studied for the methane combustion, which can efficiently reduce the reaction temperature even to ~ 300 °C5–8 These catalysts are challenged by high cost and easy poisoning[6]. It is desirable to develop efficient method to enhance the reactivity of TMOs based catalyst for methane activation at relatively low temperature. Graphene and it derivatives have atomic 2D structure with unique electronic and chemical properties, which have become versatile materials in many applications including catalysis[14,15]. Effects of GO addition on the structure and surface chemistry of the catalyst as well as the reaction stability were thoroughly investigated

Methods

Results

Conclusion