The composition limit of electrodeposited molybdenum alloys with nickel is explored from aqueous, citrate electrolytes containing high concentrations of molybdate ions compared to nickel ions. Since molybdate reduction requires the co-deposition of an inducing element, such as nickel, in aqueous media, the ability to fabricate high molybdenum content alloys are a challenge. Here, molybdenumrich, MoNi alloys were successfully, deposited galvanostatically. Electrodeposition experiments were performed on vertically placed, stationary, working electrodes. The deposit composition was characterized by XRF. Deposits having a composition ranging from 62-82 wt%, were realized, requiring high, cathodic, current densities greater than 200 mA/cm(2), although at extremely low current efficiency, less than 1%. Increasing molybdate concentration in the electrolyte resulted in an increase Mo content in the alloys at a given current density. The partial current densities of Mo, Ni and side reactions are parallel, indicative of a coupled reaction mechanism. The deposit morphology was characterized by SEM. The MoNi alloys had a nodular morphology and contained micro-cracks. The catalytic property of the MoNi alloys were characterized in a sodium hydroxide electrolyte, and exhibited Tafel behavior consistent with their hallmark feature as a catalysts for electrolytic hydrogen evolution. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.091202jes] All rights reserved.