Abstract：Single-atom catalysts (SACS) have shown great potential for achieving superior catalytic activity due to maximizing metal    efficiency. The key obstacle in developing SACS lies in the availability of supports that can stabilize SACS. Here we report the first        successful development of single gold (Au) atom catalysts supported on high-surface-area hierarchical perovskite oxides. The resulting   Au single-atoms are extremely stable at calcination temperatures up to 700 degrees C in air and under reaction conditions. A high            catalytic activity for CO oxidation and distinct self-activating property were also achieved. Furthermore, evidenced by theoretical            calculations and experimental studies including X-ray absorption fine structures and in situ Fourier-transform infrared spectra, the           surface Au active sites are confirmed to be predominately positively charged. This work provides a generalizable approach to fabricating highly stable Au single-atom catalysts with tunable catalytic performance, and we anticipate that this discovery will facilitate new           possibilities for the development of single atom catalysts.

KeyWords Plus:TOTAL-ENERGY CALCULATIONS; TEMPERATURE CO OXIDATION; WATER-GAS SHIFT; ACTIVE-SITES;   CATALYSTS; AU; SURFACE; NANOPARTICLES; ACTIVATION; CLUSTERS
Published in APPLIED CATALYSIS B-ENVIRONMENTAL，Volume: 261；10.1016/j.apcatb.2019.118178，FEB 2020