Activation of Methane on NiO Nanoparticles with Different Morphologies

Ruth L Martins,Martin Schmal

doi:10.5935/0103-5053.20140266

Abstract

Nanostructured surfaces can be defined as substrates in which the typical features have dimensions in the range of 1-100 nm. The recent focus of interest in these systems is based on the fact that interesting novel properties (catalytic, magnetic, ferroelectric, mechanical, optical and electronic) are developed as a result of the dimension reductions of these substrates. This paper describes the catalytic methane decomposition into hydrogen and carbon nanofilaments on unsupported Ni catalysts prepared from different methodologies, with controlled particle size and morphologies. Ni catalyst supported on zirconia was also used for performance comparison. For the unsupported catalysts, it was observed strong dependency of catalyst activities with particle size of nickel oxide precursors and their morphologies. Although all of them presented crystallite sizes with nanometric dimensions, only those prepared with ethylene glycol, NiEG, and by hydrothermal condition, NiHT, exhibited the same performance as the supported catalyst (activity and stability), 25NiZ. Catalyst synthesized in the presence of dimethylglyoxime, NiDMG, was less active and deactivated with time on stream.

Highlights

There are many new challenges ahead in the field of heterogeneous catalysis in terms of the chemical process and reactions to be promoted by the use of nano catalysts
Methane activation and posterior interaction between the molecules or intermediates and the surface of the catalyst and for understanding the reaction mechanisms governing the formation of C–C bonding, the reaction condition influencing the formation of these ligands, as well as, the product distribution, which are of fundamental interest, for the non-oxidative coupling and on processes related to the methane transformation
We present methane activation on Ni nanoparticles with different morphologies synthesized by different methods for the methane activation and characterized before and after activation of methane

Summary

Introduction

There are many new challenges ahead in the field of heterogeneous catalysis in terms of the chemical process and reactions to be promoted by the use of nano catalysts. The conversion of methane, which is usually performed by different direct or indirectly routes, require specific catalysts. Non oxidative methane process is relevant for investigating the different possibilities of methane activation and posterior interaction between the molecules or intermediates and the surface of the catalyst and for understanding the reaction mechanisms governing the formation of C–C bonding, the reaction condition influencing the formation of these ligands, as well as, the product distribution, which are of fundamental interest, for the non-oxidative coupling and on processes related to the methane transformation. Martins et al.[1] reported the role of different supports (silica, alumina and zirconia) on the non-oxidative conversion of methane on Pt loaded catalysts, with or without the presence of MoO3.

Results

Discussion

Conclusion