Selective catalytic hydrogenation of unsaturated aldehyde and nitro compounds requires fine control over the activation and hydrogenation of C=C, C=O, and N-O/N=O bonds. The surface chemistry of mono- and bi-metallic late transition metal catalysts often presents an improper balance between C=C and C=O/N-O hydrogenation leading to poor selectivity and hydrogenation of C=C group. Intermetallic compounds (IMC) composed of compositionally ordered mixtures of transition metals (TM) and p-block elements can present a much larger range of surface reactivity that can promote only C=O or N-O hydrogenation and fundamentally limit C=C hydrogenation.<br/><br/>Through a combined experimental and computational surface science approach, we have determined how element selection dictates bonding within and surface chemistry of late 1st-row TM IMCs. Results showed that early and smaller p-block element selection improved surface reactivity towards C=O/N-O bonds because of the electronegativity of the parent elements. Likewise, improved orbital overlap in this IMC compositional space produced more hybridized electronic structures that fundamentally limited surface chemistry towards C=C hydrogenation. Compositional stability of non-noble metal IMCs was also understood with IMCs exhibiting weak bonding suffering from surface composition change. Whereas, strong bonding within the IMC led to stable surface compositions. The fundamental effects of parent element electronegativity and type of bonding within the IMC on surface chemistry and catalyst performance will also be discussed. New synthesis methods for producing phase-pure, supported IMC nanoparticle catalysts will be superficially discussed. Full details of the synthesis techniques will be discussed in an alternate presentation.

Surface chemistry trends in IMCs for the selective hydrogenation of unsaturated aldehydes and nitro compounds

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.