Structure-dependent CO reduction on molybdenite (MoS) electrocatalysts.

Scanning electrochemical cell microscopy (SECCM) is employed to directly identify the structure-dependent electrochemical CO reduction reaction (eCORR) activity of molybdenite (MoS) electrocatalysts in an aqueous imidazolium-based aprotic ionic liquid electrolyte. Nanoscale defects, where the edge plane (EP) is exposed, are directly targeted, revealing heightened overall activity (eCORR + the competing hydrogen evolution reaction, HER) over the relatively inactive basal plane (BP). In addition, certain types of defects (, step edges) only exhibit heightened activity under a CO atmosphere (, compared to N), indirectly confirming higher selectivity at these surface sites.