Preparation and catalytic properties of a new SiO2-attached Nb-dimer catalyst: regulation of acidity–basicity by the number of metal atoms in surface active sites

Abstract

New Nb dimers on an SiO₂ surface, prepared from the reaction between [Nb(η⁵-C₅H₅)H-µ-(η⁵, η¹-C₅H₄)]₂ and surface OH groups, are found to have an oxygen-bridged dimeric structure, as characterised by extended X-ray fine structure (EXAFS), which is active and selective for the dehydration of ethanol in contrast to the dehydrogenation ability of the Nb monomer catalyst.