Spray-Dried Ni Catalysts with Tailored Properties for CO2 Methanation

Bjarne Kreitz,Jan Martin,Aurina Martínez Arias,Alfred Weber,Thomas Turek

doi:10.3390/catal10121410

Bjarne Kreitz, Jan Martin + Show 3 more

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https://doi.org/10.3390/catal10121410

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Abstract

A catalyst production method that enables the independent tailoring of the structural properties of the catalyst, such as pore size, metal particle size, metal loading or surface area, allows to increase the efficiency of a catalytic process. Such tailoring can help to make the valorization of CO2 into synthetic fuels on Ni catalysts competitive to conventional fossil fuel production. In this work, a new spray-drying method was used to produce Ni catalysts supported on SiO2 and Al2O3 nanoparticles with tunable properties. The influence of the primary particle size of the support, different metal loadings, and heat treatments were applied to investigate the potential to tailor the properties of catalysts. The catalysts were examined with physical and chemical characterization methods, including X-ray diffraction, temperature-programmed reduction, and chemisorption. A temperature-scanning technique was applied to screen the catalysts for CO2 methanation. With the spray-drying method presented here, well-organized porous spherical nanoparticles of highly dispersed NiO nanoparticles supported on silica with tunable properties were produced and characterized. Moreover, the pore size, metal particle size, and metal loading can be controlled independently, which allows to produce catalyst particles with the desired properties. Ni/SiO2 catalysts with surface areas of up to 40 m2 g−1 with Ni crystals in the range of 4 nm were produced, which exhibited a high activity for the CO2 methanation.

Highlights

Dispersed Ni nanoparticles supported on well-organized porous structures are promising catalysts for several applications such as steam and dry reforming of methane [1,2] and ethane [3,4], and methanation of CO [5,6] and CO2 [7,8]
According to our experimental results, we proved that the presented method is a flexible process that can be extended for the preparation of the catalyst particles containing different metals, which was done in previous work for Co3O4/SiO2 catalysts
One of the biggest advantages of the method presented here for the NiO/SiO2 system is the independent control of the NiO nanoparticle size and the pore size

Summary

Introduction

Dispersed Ni nanoparticles supported on well-organized porous structures are promising catalysts for several applications such as steam and dry reforming of methane [1,2] and ethane [3,4], and methanation of CO [5,6] and CO2 [7,8]. For the improvement of the CO2 methanation process and the other mentioned processes, it is, necessary to produce catalysts with long-term stability, sintering- and coking resistance as well as high activity and selectivity towards desired products. These properties are influenced on the microscale by Catalysts 2020, 10, 1410; doi:10.3390/catal10121410 www.mdpi.com/journal/catalysts. Various ceramic carriers are investigated for CO2 methanation, such as γ-Al2O3, SiO2, TiO2, CeO2, and ZrO2 [8,12,13,14]. Carriers with basic surface properties like Al2O3 and CeO2 show a high CO2 methanation activity due to the interaction of CO2 with basic adsorption sites [15]

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Conclusion