Efficient Synthesis of Ethanol from CH4 and Syngas on a Cu-Co/TiO2 Catalyst Using a Stepwise Reactor.

Zhi-Jun Zuo,Wei Huang,Fen Peng

doi:10.1038/srep34670

Abstract

Ethanol synthesis from CH4 and syngas on a Cu-Co/TiO2 catalyst is studied using experiments, density functional theory (DFT) and microkinetic modelling. The experimental results indicate that the active sites of ethanol synthesis from CH4 and syngas are Cu and CoO, over which the ethanol selectivity is approximately 98.30% in a continuous stepwise reactor. DFT and microkinetic modelling results show that *CH3 is the most abundant species and can be formed from *CH4 dehydrogenation or through the process of *CO hydrogenation. Next, the insertion of *CO into *CH3 forms *CH3CO. Finally, ethanol is formed through *CH3CO and *CH3COH hydrogenation. According to our results, small particles of metallic Cu and CoO as well as a strongly synergistic effect between metallic Cu and CoO are beneficial for ethanol synthesis from CH4 and syngas on a Cu-Co/TiO2 catalyst.

Highlights

Owing to the diminishing supply of fossil fuels and rising crude oil prices, an alternative fuel source must be developed
The experimental results indicated that ethanol can be synthesised at high efficiency from CH4 and syngas on the Cu-Co/TiO2 catalyst, over which the selectivity of ethanol is approximately 98.30%
It was found that the active sites of ethanol synthesis are metallic Cu and CoO, with metallic Cu and CoO uniformly dispersed on the catalyst surface

Summary

Introduction

Owing to the diminishing supply of fossil fuels and rising crude oil prices, an alternative fuel source must be developed. C2-oxygenate synthesis from CH4 and CO2 is thermodynamically unfavourable at low temperatures, but this can be overcome through a stepwise reaction technology that has been proposed by our group[11]. In this process, *CH4 is first adsorbed on the catalyst surface (M) and dissociated to generate CHx-M; subsequently, the *CO2 species is inserted into the C-M bond to form *CHxCOO before forming acetic acid from *CHxCOO hydrogenation[12,13,14]. The result may be useful for computational design and optimizations of Cu-Co/TiO2 catalysts

Methods

Discussion

Conclusion