Sintering and coking resistant core–shell microporous silica–nickel nanoparticles for CO methanation: Towards advanced catalysts production
Modern engineered materials have to be developed to address specific problems associated to chemical processes that directly affect our society. Catalysts are key materials used for large scale production of at least 90% of the everyday goods. Many energy transformation chains exist in which catalysts are used at relatively high temperature. Therefore, deactivation due to sintering and poisoning is a common phenomenon and often the reason for unsuccessful implementation of new catalytic processes. In this paper, a Ni-based catalyst for CO methanation is studied with the aim to address two specific issues, namely the sintering and the carbon deposition, which both hinder the stability and the efficiency of the catalyst over time. The engineered material is composed by a Ni core of about 170 nm protected by a 30-40 nm microporous SiO2 layer. The porous layer allows the gases to permeate and completely inhibits particle-particle sintering. The experimental evidences demonstrate that even in the presence of 2000 ppm of C2H4 no carbon deposition occurs on the catalyst surface. The reported materials show outstanding properties paving the way to a new class of advanced functional material with improved catalytic activity and stability. (C) 2015 Elsevier B.V. All rights reserved.