Aqueous phase catalytic and electrocatalytic hydrogenation of phenol and benzaldehyde over platinum group metals
Abstract
The mechanisms of aqueous-phase thermal catalytic hydrogenation (TCH) and electrocatalytic hydrogenation (ECH) of organic molecules over Pt group metals are not as well-understood as gas-phase thermal catalytic hydrogenation. In gas-phase, the reactions generally occur via a Langmuir-Hinshelwood mechanism with adsorbed hydrogen adding to adsorbed organics. In this article, we show that the rates, reaction orders and activation energies for TCH and ECH of phenol and benzaldehyde on Pd, Pt, and Rh can be explained with a simple kinetic model based on similar Langmuir-Hinshelwood mechanisms. For Pt/C, the adsorption equilibrium constants for the organics needed to fit the rate data are consistent with independently-measured values, provided we assume that the rates are dominated by (111)-like sites, in agreement with reported particle size effects. The reaction rate of Pd in the ECH of benzaldehyde increases with the surface hydrogen coverage. The state of Pd during ECH of phenol and benzaldehyde are very different, with a high concentration of adsorbed H in the presence of phenol, but not in the presence of benzaldehyde, consistent with benzaldehyde’s stronger binding to the surface. In consequence, Pd is converted to ß-PdHx during the hydrogenation of phenol but not benzaldehyde. This is proposed to explain the muchmore »
- Authors:
-
- Univ. of Washington, Seattle, WA (United States). Dept. of Chemistry; Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Univ. of Michigan, Ann Arbor, MI (United States)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Univ. of Washington, Seattle, WA (United States)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Technische Univ. Munchen, Garching (Germany)
- Publication Date:
- Research Org.:
- Univ. of Washington, Seattle, WA (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
- OSTI Identifier:
- 1597972
- Alternate Identifier(s):
- OSTI ID: 1595284; OSTI ID: 1775846
- Report Number(s):
- PNNL-SA-150490
Journal ID: ISSN 0021-9517
- Grant/Contract Number:
- FG02-96ER14630; AC-05-76RL01830
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Journal of Catalysis
- Additional Journal Information:
- Journal Volume: 382; Journal Issue: C; Journal ID: ISSN 0021-9517
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Electrocatalysis; Hydrogenation; Langmuir-Hinshelwood
Citation Formats
Singh, Nirala, Sanyal, Udishnu, Ruehl, Griffin, Stoerzinger, Kelsey A., Gutiérrez, Oliver Y., Camaioni, Donald M., Fulton, John L., Lercher, Johannes A., and Campbell, Charles T. Aqueous phase catalytic and electrocatalytic hydrogenation of phenol and benzaldehyde over platinum group metals. United States: N. p., 2020.
Web. doi:10.1016/j.jcat.2019.12.034.
Singh, Nirala, Sanyal, Udishnu, Ruehl, Griffin, Stoerzinger, Kelsey A., Gutiérrez, Oliver Y., Camaioni, Donald M., Fulton, John L., Lercher, Johannes A., & Campbell, Charles T. Aqueous phase catalytic and electrocatalytic hydrogenation of phenol and benzaldehyde over platinum group metals. United States. https://doi.org/10.1016/j.jcat.2019.12.034
Singh, Nirala, Sanyal, Udishnu, Ruehl, Griffin, Stoerzinger, Kelsey A., Gutiérrez, Oliver Y., Camaioni, Donald M., Fulton, John L., Lercher, Johannes A., and Campbell, Charles T. Fri .
"Aqueous phase catalytic and electrocatalytic hydrogenation of phenol and benzaldehyde over platinum group metals". United States. https://doi.org/10.1016/j.jcat.2019.12.034. https://www.osti.gov/servlets/purl/1597972.
@article{osti_1597972,
title = {Aqueous phase catalytic and electrocatalytic hydrogenation of phenol and benzaldehyde over platinum group metals},
author = {Singh, Nirala and Sanyal, Udishnu and Ruehl, Griffin and Stoerzinger, Kelsey A. and Gutiérrez, Oliver Y. and Camaioni, Donald M. and Fulton, John L. and Lercher, Johannes A. and Campbell, Charles T.},
abstractNote = {The mechanisms of aqueous-phase thermal catalytic hydrogenation (TCH) and electrocatalytic hydrogenation (ECH) of organic molecules over Pt group metals are not as well-understood as gas-phase thermal catalytic hydrogenation. In gas-phase, the reactions generally occur via a Langmuir-Hinshelwood mechanism with adsorbed hydrogen adding to adsorbed organics. In this article, we show that the rates, reaction orders and activation energies for TCH and ECH of phenol and benzaldehyde on Pd, Pt, and Rh can be explained with a simple kinetic model based on similar Langmuir-Hinshelwood mechanisms. For Pt/C, the adsorption equilibrium constants for the organics needed to fit the rate data are consistent with independently-measured values, provided we assume that the rates are dominated by (111)-like sites, in agreement with reported particle size effects. The reaction rate of Pd in the ECH of benzaldehyde increases with the surface hydrogen coverage. The state of Pd during ECH of phenol and benzaldehyde are very different, with a high concentration of adsorbed H in the presence of phenol, but not in the presence of benzaldehyde, consistent with benzaldehyde’s stronger binding to the surface. In consequence, Pd is converted to ß-PdHx during the hydrogenation of phenol but not benzaldehyde. This is proposed to explain the much lower activity of Pd for hydrogenation of phenol compared to benzaldehyde. The measured low coverage of H on Pd in the presence of benzaldehyde is in agreement with the high selectivity/Faradaic efficiency of protons to benzaldehyde hydrogenation to benzyl alcohol. The decrease in apparent activation energy for ECH versus TCH can also be understood within this same kinetic model. The combination of ECH and TCH kinetics and spectroscopy has, thus, allowed to deduce a microkinetic model for these hydrogenation reactions.},
doi = {10.1016/j.jcat.2019.12.034},
journal = {Journal of Catalysis},
number = C,
volume = 382,
place = {United States},
year = {Fri Jan 17 00:00:00 EST 2020},
month = {Fri Jan 17 00:00:00 EST 2020}
}
Web of Science