Role of Nanointerfaces in Cu‐ and Cu+Au‐Based Near‐Ambient‐Temperature CO Oxidation Catalysts

Disordered mesoporous Cu‐doped ceria‐zirconia (Cu 0.1 Ce 0.85 Zr 0.05 O 2 ), and gold deposited (Au/Cu 0.1 Ce 0.85 Zr 0.05 O 2 ) catalysts were synthesized and evaluated for CO oxidation. Onset of CO oxidation activity, and 50 % (100 %) CO 2 formation occurs at room temperature (RT), and 77 (120)°C, respectively, with Cu 0.1 Ce 0.85 Zr 0.05 O 2 . A small amount of gold on Cu 0.1 Ce 0.85 Zr 0.05 O 2 induces the sustainable oxidation catalysis around RT. Onset of copper reduction temperature decreases from 110 °C on Cu 0.1 Ce 0.85 Zr 0.05 O 2 to 48 °C with Au/Cu 0.1 Ce 0.85 Zr 0.05 O 2 , highlighting the direct interaction between Cu and Au through a Cu–Au interface. Au particles with a (0 0 1) facet deposit on an oxygen‐deficient site of (1 1 1) facet of CeO 2 ‐ZrO 2 . Any decrease in surface Cu‐content with increasing Au‐content further supports the Au‐Cu‐Ce/Zr interface interactions. Nanointerfaces of Au clusters on Cu next to oxygen‐deficient sites of CeO 2 ‐ZrO 2 facilitate all the elementary steps of the CO+O 2 reaction to occur in close proximity at ambient conditions.