Journal of Physical Chemistry C | 2019
Combined Experimental and Theoretical Molecular Approachof the Catalytically Active Hydrotreating MoS 2 Phases Promotedby 3d Transition Metals
Abstract
High-throughput synthesis combined with a surface organometallic (coordination) chemistry approach is used to prepare in a systematic way a series of 40 metal-promoted (Me)–MoS2 active phases supported on amorphous silica alumina with various Me/Mo ratios (0–0.5). The intrinsic catalytic activity in a model reaction, namely, toluene hydrogenation, evaluated also by a high-throughput method shows a well-marked Me/Mo optimal ratio corresponding to an improved catalytic activity with respect to the MoS2 reference for Me = Fe, Co, and Ni. In contrast, no impact is observed for Zn, while a negative impact on the activity is observed for Ti and Cu. To rationalize these results, the thermodynamic stabilities, local structures, and magnetic properties of the Me atoms at the edges of the MoS2 nanocrystallite are examined by the density functional theory (DFT) calculations. The calculated edge energy descriptor unambiguously categorizes the different types of MeMoS mixed phases. Optimal intermediate edge energies a...