Octahedral gold-silver nanoframes with rich crystalline defects for efficient methanol oxidation manifesting a CO-promoting effect.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31439841.
- Also identified by DOI 10.1038/s41467-019-11766-w and PMC identifier 6706449.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Three-dimensional bimetallic nanoframes with high spatial diffusivity and surface heterogeneity possess remarkable catalytic activities owing to their highly exposed active surfaces and tunable electronic structure. Here we report a general one-pot strategy to prepare ultrathin octahedral Au<sub>3</sub>Ag nanoframes, with the formation mechanism explicitly elucidated through well-monitored temporal nanostructure evolution. Rich crystalline defects lead to lowered atomic coordination and varied electronic states of the metal atoms as evidenced by extensive structural characterizations. When used for electrocatalytic methanol oxidation, the Au<sub>3</sub>Ag nanoframes demonstrate superior performance with a high specific activity of 3.38 mA cm<sup>-2</sup>, 3.9 times that of the commercial Pt/C. More intriguingly, the kinetics of methanol oxidation on the Au<sub>3</sub>Ag nanoframes is counter-intuitively promoted by carbon monoxide. The enhancement is ascribed to the altered reaction pathway and enhanced OH<sup>-</sup> co-adsorption on the defect-rich surfaces, which can be well understood from the d-band model and comprehensive density functional theory simulations.