Document Type
Article
Publication Date
3-2019
Abstract
We report a quantitative kinetic evaluation and study of support effects for partial alkyne hydrogenation using oleylaminecapped Au colloids as catalyst precursors. The amine capping agents can be removed under reducing conditions, generating supported Au nanoparticles of ~2.5 nm in diameter. The catalysts showed high alkene selectivity (>90%) at all conversions during alkyne partial hydrogenation. Catalytic activity, observed rate constants, and apparent activation energies (25– 40 kJ/mol) were similar for all Au catalysts, indicating support effects are relatively small. Alkyne adsorption, probed with FTIR and DFT, showed adsorption on the support was associated with hydrogen-bonding interactions. DFT calculations indicate strong alkyne adsorption on Au sites, with the strongest adsorption sites at the metal-support interface (MSI). The catalysts had similar hydrogen reaction orders (0.7–0.9), and 1- octyne reaction orders (~ 0.2), suggesting a common mechanism. The reaction kinetics are most consistent with a mechanism involving the non-competitive activated adsorption of H2 on an alkyne-covered Au surface.
DOI
10.1002/cctc.2018
Publisher
Wiley-Blackwell
Repository Citation
Bruno, J. E., Sravan Kumar, K. B., Dwarica, N. S., Hüther, A., Chen, Z., Guzman, C. S., IV, Hand, E. R., ... & Chandler, B. D. (2019). On the limited role of electronic support effects in selective alkyne hydrogenation: A kinetic study of Au/MOx catalysts prepared from oleylamine-capped colloidal nanoparticles. ChemCatChem, 11(6), 1650-1664. https://doi.org/10.1002/cctc.2018
Publication Information
ChemCatChem