Abstract
Hydrogen activation is a key step in many reactions like hydrogenations and other processes as the reverse water gas shift reaction. Therefore, the comprehension of the mechanism of hydrogen activation would sustain the understanding of the whole reaction mechanism as well as of the role played either by the gold or by the support. FTIR spectroscopy has been employed as a tool in order to improve the actual knowledge on these topics. Hydrogen interaction with the Au/TiO 2 reference catalyst provided by the World Gold Council, containing mainly gold nanoparticles, and with two samples, Au/CeO 2 and Au/ZrO 2, in which gold clusters are present, has been performed. Hydrogen is dissociated at room temperature on the edge and corner sites of both nanoparticles and clusters, independently from the nature of the support. FTIR evidences of the formation of Au–H and Au–OH species are presented for the first time. These species are strongly bonded to Au and compete with CO adsorption. In addition, the spillover of the H atoms takes place on titania, H atoms are ionized to H + and the released electrons populate the conduction band, as testified by a monotonous absorption that grows at increasing contact time and pressure. The species observed in this paper can play a role on the activity and selectivity of gold catalysts in reactions involving hydrogen dissociation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.