This study reveals the in situ three-dimensional strain evolution of single gold nanocrystals during a catalytic CO oxidation reaction using coherent X-ray diffractive imaging. Anisotropic strain dynamics at the nanoscale were observed, showing that identically oriented facets are affected differently by strain, leading to preferential active site formation. The single nanoparticle elastic energy landscape, mapped with attojoule precision, shows a dependence on heating versus cooling cycles, correlating with the observed catalytic hysteresis. This research provides insights into nanoscale catalytic mechanisms and deactivation processes.

Aline R. Passos, Amélie Rochet, Luiza M. Manente, Ana F. Suzana, Ross Harder, Wonsuk Cha, Florian Meneau