skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Reaction of Trimethylaluminum with Water on Pt(111) and Pd(111) from 10 –5 to 10 –1 Millibar

Abstract

The reaction between adsorbed trimethylaluminum (TMA) and water was studied on Pt(111) and Pd(111) surfaces. Upon exposure to TMA at approximately 10–5 mbar, C- and Al-containing species appeared on both surfaces, as observed by X-ray photoelectron spectroscopy (XPS). On both surfaces, the adsorbed Al oxidation state observed by XPS was closest to metallic. Density functional theory (DFT) calculations suggest that decomposition to methyl aluminum (Al-CH3; “MMA”) or atomic Al is thermodynamically favorable. The formation of a Pd–Al alloy was observed on Pd(111), but Pt–Al alloy formation was not observed on Pt(111). Following TMA adsorption, each surface was exposed to water vapor at 400 °C either at a pressure of 7 × 10–6 mbar (UHV-XPS) or at 0.1 mbar (in situ XPS). The substrate and water dosing conditions determined the ability of each surface to remove residual carbon: on Pt(111), carbon from the TMA precursor was removed from Pt(111) during 0.1 mbar water exposure at 400 °C, whereas carbon was not removed after the 7 × 10–6 mbar water exposure. On Pd(111), however, carbon-containing fragments of TMA were removed at both water pressures. XPS also revealed another effect of water dosing conditions: the as-deposited Al was only fully oxidized to Al2O3more » during water exposure at 0.1 mbar, whereas mixed hydroxide-containing and metallic Al species persisted after exposure to water at 7 × 10–6 mbar on both surfaces.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Institute for Atom-efficient Chemical Transformations (IACT)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1385885
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry. C; Journal Volume: 119; Journal Issue: 5; Related Information: IACT partners with Argonne National Laboratory (lead); Brookhaven National Laboratory; Northwestern University; Purdue University; University of Wisconsin at Madison
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; catalysis (homogeneous), catalysis (heterogeneous), biofuels (including algae and biomass), bio-inspired, materials and chemistry by design, synthesis (novel materials), synthesis (scalable processing)

Citation Formats

Detwiler, Michael D., Gharachorlou, Amir, Mayr, Lukas, Gu, Xiang-Kui, Liu, Bin, Greeley, Jeffrey, Delgass, W. Nicholas, Ribeiro, Fabio H., and Zemlyanov, Dmitry Y.. Reaction of Trimethylaluminum with Water on Pt(111) and Pd(111) from 10 –5 to 10 –1 Millibar. United States: N. p., 2015. Web. doi:10.1021/jp510032u.
Detwiler, Michael D., Gharachorlou, Amir, Mayr, Lukas, Gu, Xiang-Kui, Liu, Bin, Greeley, Jeffrey, Delgass, W. Nicholas, Ribeiro, Fabio H., & Zemlyanov, Dmitry Y.. Reaction of Trimethylaluminum with Water on Pt(111) and Pd(111) from 10 –5 to 10 –1 Millibar. United States. doi:10.1021/jp510032u.
Detwiler, Michael D., Gharachorlou, Amir, Mayr, Lukas, Gu, Xiang-Kui, Liu, Bin, Greeley, Jeffrey, Delgass, W. Nicholas, Ribeiro, Fabio H., and Zemlyanov, Dmitry Y.. Thu . "Reaction of Trimethylaluminum with Water on Pt(111) and Pd(111) from 10 –5 to 10 –1 Millibar". United States. doi:10.1021/jp510032u.
@article{osti_1385885,
title = {Reaction of Trimethylaluminum with Water on Pt(111) and Pd(111) from 10 –5 to 10 –1 Millibar},
author = {Detwiler, Michael D. and Gharachorlou, Amir and Mayr, Lukas and Gu, Xiang-Kui and Liu, Bin and Greeley, Jeffrey and Delgass, W. Nicholas and Ribeiro, Fabio H. and Zemlyanov, Dmitry Y.},
abstractNote = {The reaction between adsorbed trimethylaluminum (TMA) and water was studied on Pt(111) and Pd(111) surfaces. Upon exposure to TMA at approximately 10–5 mbar, C- and Al-containing species appeared on both surfaces, as observed by X-ray photoelectron spectroscopy (XPS). On both surfaces, the adsorbed Al oxidation state observed by XPS was closest to metallic. Density functional theory (DFT) calculations suggest that decomposition to methyl aluminum (Al-CH3; “MMA”) or atomic Al is thermodynamically favorable. The formation of a Pd–Al alloy was observed on Pd(111), but Pt–Al alloy formation was not observed on Pt(111). Following TMA adsorption, each surface was exposed to water vapor at 400 °C either at a pressure of 7 × 10–6 mbar (UHV-XPS) or at 0.1 mbar (in situ XPS). The substrate and water dosing conditions determined the ability of each surface to remove residual carbon: on Pt(111), carbon from the TMA precursor was removed from Pt(111) during 0.1 mbar water exposure at 400 °C, whereas carbon was not removed after the 7 × 10–6 mbar water exposure. On Pd(111), however, carbon-containing fragments of TMA were removed at both water pressures. XPS also revealed another effect of water dosing conditions: the as-deposited Al was only fully oxidized to Al2O3 during water exposure at 0.1 mbar, whereas mixed hydroxide-containing and metallic Al species persisted after exposure to water at 7 × 10–6 mbar on both surfaces.},
doi = {10.1021/jp510032u},
journal = {Journal of Physical Chemistry. C},
number = 5,
volume = 119,
place = {United States},
year = {Thu Jan 22 00:00:00 EST 2015},
month = {Thu Jan 22 00:00:00 EST 2015}
}