AuPt Alloy Nanoparticles for CO-Tolerant Hydrogen Activation: Architectural Effects in Au-Pt Bimetallic Nanocatalysts

Authors


  • This work is supported by the NSF under Grant No. 0401850 and the U.S. DOE's Oak Ridge National Lab under the Advanced Reciprocating Engine Systems Program. Supporting Information is available online from Wiley InterScience or from the authors.

Abstract

Colloidal suspensions of AuPt alloy nanoparticles (NPs) were prepared by using a rapid butyllithium reduction of Au3+ and Pt4+ precursors in oleylamine. The resulting 2.5 nm (av) particles were characterized by TEM with EDX, XRD, XPS and UV-vis spectroscopy. With less butyllithium, nanowires are formed from fused NPs and grow to 100 nm in length. The activities of three different AuPt NP architectures (alloy, contact aggregate and monometallic NPs) were evaluated for catalytic hydrogen oxidation in CO-contaminated fuel streams (1.0 % Pt loadings in Al2O3 supports). The alloy catalyst showed superior H2 and CO oxidation activity, was unaffected by iron promoters and appears to operate by a different mechanism. The heteroaggregate showed a marked improvement in activity with iron promoters and is more selective for CO oxidation.

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