TY - JOUR
T1 - Au–Pd separation enhances bimetallic catalysis of alcohol oxidation
AU - Huang, Xiaoyang
AU - Akdim, Ouardia
AU - Douthwaite, Mark
AU - Wang, Kai
AU - Zhao, Liang
AU - Lewis, Richard J.
AU - Pattisson, Samuel
AU - Daniel, Isaac T.
AU - Miedziak, Peter J.
AU - Shaw, Greg
AU - Morgan, David J.
AU - Althahban, Sultan M.
AU - Davies, Thomas E.
AU - He, Qian
AU - Wang, Fei
AU - Fu, Jile
AU - Bethell, Donald
AU - McIntosh, Steven
AU - Kiely, Christopher J.
AU - Hutchings, Graham J.
N1 - Compliant deposit in Cardiff ORCA: https://orca.cardiff.ac.uk/id/eprint/147017/
PY - 2022/3/10
Y1 - 2022/3/10
N2 - In oxidation reactions catalysed by supported metal nanoparticles with oxygen as the terminal oxidant, the rate of the oxygen reduction can be a limiting factor. This is exemplified by the oxidative dehydrogenation of alcohols, an important class of reactions with modern commercial applications1–3. Supported gold nanoparticles are highly active for the dehydrogenation of the alcohol to an aldehyde4 but are less effective for oxygen reduction5,6. By contrast, supported palladium nanoparticles offer high efficacy for oxygen reduction5,6. This imbalance can be overcome by alloying gold with palladium, which gives enhanced activity to both reactions7,8,9; however, the electrochemical potential of the alloy is a compromise between that of the two metals, meaning that although the oxygen reduction can be improved in the alloy, the dehydrogenation activity is often limited. Here we show that by separating the gold and palladium components in bimetallic carbon-supported catalysts, we can almost double the reaction rate compared with that achieved with the corresponding alloy catalyst. We demonstrate this using physical mixtures of carbon-supported monometallic gold and palladium catalysts and a bimetallic catalyst comprising separated gold and palladium regions. Furthermore, we demonstrate electrochemically that this enhancement is attributable to the coupling of separate redox processes occurring at isolated gold and palladium sites. The discovery of this catalytic effect—a cooperative redox enhancement—offers an approach to the design of multicomponent heterogeneous catalysts.
AB - In oxidation reactions catalysed by supported metal nanoparticles with oxygen as the terminal oxidant, the rate of the oxygen reduction can be a limiting factor. This is exemplified by the oxidative dehydrogenation of alcohols, an important class of reactions with modern commercial applications1–3. Supported gold nanoparticles are highly active for the dehydrogenation of the alcohol to an aldehyde4 but are less effective for oxygen reduction5,6. By contrast, supported palladium nanoparticles offer high efficacy for oxygen reduction5,6. This imbalance can be overcome by alloying gold with palladium, which gives enhanced activity to both reactions7,8,9; however, the electrochemical potential of the alloy is a compromise between that of the two metals, meaning that although the oxygen reduction can be improved in the alloy, the dehydrogenation activity is often limited. Here we show that by separating the gold and palladium components in bimetallic carbon-supported catalysts, we can almost double the reaction rate compared with that achieved with the corresponding alloy catalyst. We demonstrate this using physical mixtures of carbon-supported monometallic gold and palladium catalysts and a bimetallic catalyst comprising separated gold and palladium regions. Furthermore, we demonstrate electrochemically that this enhancement is attributable to the coupling of separate redox processes occurring at isolated gold and palladium sites. The discovery of this catalytic effect—a cooperative redox enhancement—offers an approach to the design of multicomponent heterogeneous catalysts.
U2 - 10.1038/s41586-022-04397-7
DO - 10.1038/s41586-022-04397-7
M3 - Article
C2 - 35038718
AN - SCOPUS:85122778382
VL - 603
SP - 271
EP - 275
JO - Nature
JF - Nature
SN - 0028-0836
IS - 7900
ER -