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Abstract The role of interfaces and the controlling synthesis parameters of graded dealloyed nanoporous metallic materials are investigated, focusing on the dealloying front progression in complex precursor materials with multiple alloy compositions. Specifically, the effects of relative density and chemical potential on the dealloying front in sputtered bilayer copper alloy films are explored with two case studies: Cu–Al/Cu–Al and Cu–Al/Cu–Zn. Cross-sectional scanning electron (SEM) micrographs and energy-dispersive X-ray spectroscopy mapping trace the dealloying front across three time intervals, while top-surface and cross-sectional SEM probes the final dealloyed foam morphology. Final ligament sizes were found to be independent of the synthesis parameters (21–28 nm), due to a combination of fast reaction times and phosphate-inhibited surface diffusion of Cu atoms. The chemical potential gradient yielded faster reaction times, whereas slower reaction times and a higher at.% of Cu in the top layer of precursor material produced a more uniform morphology. Graphical abstract
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Dealloyed Nanoporous Gold Catalysts: From Macroscopic Foams to Nanoparticulate Architectures
Abstract Dealloyed nanoporous Au membranes and spongy Au nanoparticles exhibit a set of unique structural features highly desirable for heterogeneous catalysis and electrocatalysis. In this Focus Review, we present the state‐of‐the‐art understanding of the complex mechanisms dictating the nanoscale porosity evolution during percolation dealloying of alloys and the structure‐composition‐performance correlations underpinning the catalytic behaviors of dealloyed nanoporous Au. We focus on several fundamentally intriguing but widely debated topics concerning the nature of the active sites, the dynamic surface reconstruction under reaction conditions, and the origin of catalytic selectivity toward certain reactions. We also provide perspectives on versatile dealloying‐based synthetic approaches for precise architectural tailoring of metallic nanocatalysts as well as exciting opportunities of harnessing the combined optical and catalytic properties of dealloyed nanoporous Au to drive or enhance unconventional interfacial chemical transformations.
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- Award ID(s):
- 1655740
- PAR ID:
- 10067319
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemNanoMat
- Volume:
- 4
- Issue:
- 9
- ISSN:
- 2199-692X
- Format(s):
- Medium: X Size: p. 897-908
- Size(s):
- p. 897-908
- Sponsoring Org:
- National Science Foundation
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