Supported Au nanoparticles: good for methanol decomposition or formation?

In the three decades since Haruta’s discovery of the unexpected reactivity of oxide-supported Au nanoparticles, we have come a long way in the application of nanoparticles as catalysts for a variety of reactions. Yet, the phenomenon is far from being fully understood as a number of factors control both the reactivity and the product selectivity of these nanocatalysts: the size, the shape, the support, the coadsorbates are all found to play a role. In this talk, I will compare and contrast the local electronic structural and geometric environments for the active sites on Au nanoparticles, on three different supports: single-layer MoS 2 , single-layer h-BN and the TiO 2 (110) surface. I will show that while the interface plays a major role in methanol decomposition [1] and CO oxidation facilitated by Au nanoparticles supported on TiO 2 (110), the same is not the case when these nanoparticles are supported on single-layer MoS 2 , single- layer h-BN. In fact, the Au/MoS 2 composite favors the formation of methanol (and higher alcohols) from syn gas [2]. I will trace these differences to the Au-support interaction, the ensuing charge transfer, the role of vacancies, and the extent to which the system frontier orbitals are shifted towards the Fermi level.\\ \\ [1] S. Hong and T. S. Rahman, JACS, 135, 7629 (2013)\\ [2] T. B. Rawal, D. Le, and T. S. Rahman, J. Phys.: Condens. Matter 29 415201 (2017).