Kinetics of Lifetime Changes in Bimetallic Nanocatalysts Revealed by Quick X-ray Absorption Spectroscopy.

ABSTRACT: Alloyed metal nanocatalysts are of environmental and economic importance in a plethora of chemical technologies. During the catalyst lifetime, supported alloy nanoparticles undergo dynamic changes which are well-recognized but still poorly understood. High-temperature O₂ -H₂ redox cycling was applied to mimic the lifetime changes in model Pt₁₃ In₉ nanocatalysts, while monitoring the induced changes by in?situ quick X-ray absorption spectroscopy with one-second resolution. The different reaction steps involved in repeated Pt₁₃ In₉ segregation-alloying are identified and kinetically characterized at the single-cycle level. Over longer time scales, sintering phenomena are substantiated and the intraparticle structure is revealed throughout the catalyst lifetime. The in?situ time-resolved observation of the dynamic habits of alloyed nanoparticles and their kinetic description can impact catalysis and other fields involving (bi)metallic nanoalloys.

SUBMITTER: Filez M 

PROVIDER: S-EPMC6175175 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature