TY - JOUR
T1 - Site-dependent activity of atomic Ti catalysts in Al-based hydrogen storage materials
AU - Al-Mahboob, Abdullah
AU - Muller, Erik
AU - Karim, Altaf
AU - Muckerman, James T.
AU - Ciobanu, Cristian V.
AU - Sutter, Peter
PY - 2012/6/27
Y1 - 2012/6/27
N2 - Doping catalytically inactive materials with dispersed atoms of an active species is a promising route toward realizing ultradilute binary catalyst systems. Beyond catalysis, strategically placed metal atoms can accelerate a wide range of solid-state reactions, particularly in hydrogen storage processes. Here we analyze the role of atomic Ti catalysts in the hydrogenation of Al-based hydrogen storage materials. We show that Ti atoms near the Al surface activate gas-phase H 2, a key step toward hydrogenation. By controlling the placement of Ti, we have found that the overall reaction, comprising H 2 dissociation and H spillover onto the Al surface, is governed by a pronounced trade-off between lowering of the H 2 dissociation barrier and trapping of the products near the active site, with a sharp maximum in the overall activity for Ti in the subsurface layer. Our findings demonstrate the importance of controlling the placement of the active species in optimizing the activity of dilute binary systems.
AB - Doping catalytically inactive materials with dispersed atoms of an active species is a promising route toward realizing ultradilute binary catalyst systems. Beyond catalysis, strategically placed metal atoms can accelerate a wide range of solid-state reactions, particularly in hydrogen storage processes. Here we analyze the role of atomic Ti catalysts in the hydrogenation of Al-based hydrogen storage materials. We show that Ti atoms near the Al surface activate gas-phase H 2, a key step toward hydrogenation. By controlling the placement of Ti, we have found that the overall reaction, comprising H 2 dissociation and H spillover onto the Al surface, is governed by a pronounced trade-off between lowering of the H 2 dissociation barrier and trapping of the products near the active site, with a sharp maximum in the overall activity for Ti in the subsurface layer. Our findings demonstrate the importance of controlling the placement of the active species in optimizing the activity of dilute binary systems.
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U2 - 10.1021/ja304203y
DO - 10.1021/ja304203y
M3 - Article
C2 - 22694246
AN - SCOPUS:84863424586
VL - 134
SP - 10381
EP - 10384
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 25
ER -