Isomer-dependent adsorption of cyanopyridines on platinum probed by surface-enhanced Raman spectroscopy

Xu, Minmin; Yan, Lijuan; Wei, Chao; Yang, Fengzhu; Yuan, Yaxian; Yao, Jianlin; Han, Sanyang; Wang, Mei; Gu, Ruixia

doi:10.1016/j.jelechem.2011.09.020

Cited by 4 publications

(2 citation statements)

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“…We assign the intense band at 1022 cm –1 in the red curve of Figure to the in-plane ring-breathing mode of 4-acetylpyridine that occurs at 993 cm –1 in the spectrum of the free compound . Upon adsorption the ring-breathing mode of pyridine derivatives blue shifts due to the surface bonding through the N atom . The significant blue shift of 29 cm –1 of the ring-breathing mode indicates therefore that 4-acetylpyridine binds through the N atom to the platinum surface in a vertical adsorption mode.…”

Section: Resultsmentioning

confidence: 92%

“…31 Upon adsorption the ring-breathing mode of pyridine derivatives blue shifts due to the surface bonding through the N atom. 32 The significant blue shift of 29 cm –1 of the ring-breathing mode indicates therefore that 4-acetylpyridine binds through the N atom to the platinum surface in a vertical adsorption mode. This is in agreement with the general tendency of pyridine to bind vertically to platinum surfaces.…”

Section: Resultsmentioning

confidence: 99%

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Electrochemical Reduction of the Carbonyl Functional Group: The Importance of Adsorption Geometry, Molecular Structure, and Electrode Surface Structure

Bondue

Koper

2019

J. Am. Chem. Soc.

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This paper studies the electrochemical hydrogenation of the carbonyl functional group of acetophenone and 4-acetylpyridine at platinum single-crystal electrodes. Comparison with results obtained for the hydrogenation of acetone featuring an isolated carbonyl functional group reveals the influence of the phenyl ring and the pyridine ring, respectively. Lack of acetone adsorption at Pt(111) and Pt(100) due to a weak interaction between surface and carbonyl functional group renders these surfaces inactive for the hydrogenation of acetone. Adsorption through a strong interaction with the phenyl ring of acetophenone activates the Pt(111) and Pt(100) surfaces for hydrogenation of the acetyl substituent. In agreement with previous results for acetone reduction, the Pt(100) surface is specifically active for the hydrogenolysis reaction, breaking the C–O bond, whereas the other surfaces only hydrogenate the carbonyl functionality. In contrast to the phenyl ring, the pyridine ring has a very different effect: due to the dominant interaction of the N atom of the pyridine ring with the platinum electrode, a vertical adsorption mode is realized. The resulting large physical distance between the carbonyl functional group and the electrode surface inhibits the hydrogenation at all platinum surfaces. This also holds for the Pt(110) electrode, which is otherwise active for the electrochemical hydrogenation of the isolated carbonyl functional group of aliphatic ketones. Our results show how the combination of molecular structure of the reactant and surface structure of the catalyst determine the selective electroreduction of functionalized ketones.

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Section: Resultsmentioning

confidence: 92%

Section: Resultsmentioning

confidence: 99%