Supported heterogeneous catalysts: what controls cobalt nanoparticle dispersion on alumina?

Abstract

Bright field TEM and EFTEM overlay of Co and O maps highlight distribution of cobalt nanoparticles on alumina support.

Selective Hydrogenation of 5-Hydroxymethylfurfural via Zeolite Encapsulation to Avoid Further Hydrodehydroxylation

“…5−8 However, to maintain the specific morphology of synthesized nanoparticles on the support, hightemperature thermal treatment should be avoided during the synthesis, resulting in a relatively low thermal stability in practical applications. 9 Introduction of a ligand containing N or S groups on the surface of supported nanoparticles is another general method to improve catalytic selectivity. 10−12 Because of the steric hindrance of ligands adsorbed on metal surface, reactants could regulate adsorption conformation to access and to react, which has provided the chance to improve the catalytic selectivity; however, leaching of ligands is hardly avoidable.…”

“…Thanks to the development of colloidal chemistry, transition-metal nanoparticles could be synthesized with well-defined facets and sizes. Subsequently, loading these defined nanoparticles on the support as heterogeneous catalysts could usually exhibit good catalytic selectivity for the transformation of molecules with multifunctional groups. − However, to maintain the specific morphology of synthesized nanoparticles on the support, high-temperature thermal treatment should be avoided during the synthesis, resulting in a relatively low thermal stability in practical applications . Introduction of a ligand containing N or S groups on the surface of supported nanoparticles is another general method to improve catalytic selectivity. − Because of the steric hindrance of ligands adsorbed on metal surface, reactants could regulate adsorption conformation to access and to react, which has provided the chance to improve the catalytic selectivity; however, leaching of ligands is hardly avoidable. , Although a strong interaction between metal and support can also promote catalytic selectivity, the generality of such control method is limited because of dependence on the trial-and-error approach. , Therefore, it is still a great challenge to rationally design and develop an efficient and general regulation strategy to improve catalytic selectivity.…”