Magnifying the Morphology Change Induced by a Nickel Promoter in Tungsten(IV) Sulfide Industrial Hydrocracking Catalyst: A HAADF‐STEM and DFT Study

Changes in the two‐dimensional (2D) morphology of nonpromoted WS2 and Ni‐promoted WS2 (NiWS) catalytically active nanolayers supported on amorphous silica‐alumina (ASA) are revealed by aberration‐corrected scanning transmission electron microscopy and rationalized by density functional theory calculations. The presence of the Ni atoms modifies the triangular shape of nonpromoted WS2/ASA nanolayers into a more hexagonal one for NiWS/ASA by stabilizing the S edge more strongly than the W edge. The higher catalytic activity induced by the addition of the promoter confirms the relevance of such a morphology effect for industrial catalysts.