Isolating Single Sn Atoms in CuO Mesocrystal to Form Ordered Atomic Interfaces: An Effective Strategy for Designing Highly Efficient Mesocrystal Catalysts.

Tuning the electronic structures of mesocrystals at the atomic level is an effective approach to obtaining unprecedented properties. Here, a lattice-confined strategy to obtain isolated single-site Sn atoms in CuO mesocrystals to improve catalytic performance is reported. The Sn/CuO mesocrystal composite (Sn/CuO MC) has ordered Sn-O-Cu atomic interfaces originated from the long-range ordering of the CuO mesocrystal itself. X-ray absorption fine structure measurements confirm that the positively charged Sn atoms can tune the electronic structure of the Cu atoms to some extent in Sn/CuO MC, quite different from that in the conventional single-atom Sn-modified CuO nanoparticles and nanoparticulate SnO -modified CuO mesocrystal catalysts. When tested for the Si hydrochlorination reaction to produce trichlorosilane, Sn/CuO MC exhibits significantly better performances than the above two catalysts. Theoretical calculations further reveal the electronic modification to the active Cu component and the induced improvement in HCl adsorption, and thus enhance the catalytic performance. This work demonstrates how to design efficient metal oxide mesocrystal catalysts through an electronic structure modification approach.