Advancing the development of multifunctional materials for catalytic applications

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Aromatic compounds (compounds which contain a benzene ring) are important platform chemicals in the chemical industry, with extended products from the hydrogenation of the aromatic ring being relevant for a number of applications. For example, the hydrogenation of napthelene (best known as the main ingredient of traditional mothballs) generates tetralin, octahydronaphthalene and decalin.

Tetralin and decalin are mainly used as grease, resin and rubber dissolving agents as well as varnish removers and additives in lubricants, dyes, pesticides and pharmaceuticals.  However, despite their extensive use in the petrochemical industry, the removal of aromatics is of great practical significance due to their inherent toxicity and carcinogenic effects. 

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Catalytic hydrogenation has been extensively employed for the removal of aromatics. Heterogeneous catalysts can include non-noble metal catalysts (nickel-based), precious metal catalysts (platinum-based, palladium-based, rhodium-based, ruthenium-based, and bimetallic-based (Pt– Pd)) and some novel types of catalysts such as transition metal carbides, nitrides and phosphides. Finding an optimal way to design and develop low-cost, highly efficient and selective nanocatalysts for catalytic hydrogenation of aromatics at room temperature is significant not only for fundamental research but also for potential industrial applications.

In this study, a novel Ru/Ni/Ni(OH)2/C catalyst, which is a hybrid of Ru nanoclusters anchored on Ni/Ni(OH)2 nanoparticles (NPs), was designed, prepared and characterised. XAS studies were carried out on beamline B18 at Diamond Light Source and coupled with other characterisation studies; the catalytic performance of this hybrid catalyst was tested for the selective hydrogenation of naphthalene. The results have shown that it not only exhibits high catalytic activity but also 100% selectivity to decalin. These results offer a new approach to designing multi-metallic nanocatalysts which can take full advantage of metal atoms (especially precious metal atoms) and contribute greatly towards advancing the development of multifunctional materials for catalytic applications.

 

 

Design of the ruthenium nanoclusters-on-nickel-on-nickel hydroxide nanoparticle hybrid (Ru/Ni/Ni(OH)2/C). (Image ©Royal Society of Chemistry) 

Read the full paper here – DOI: 10.1039/C7TA01437F