A process for synthesizing metal submicron and nano-scale powders for use in articles of manufacture. In a suitable reactor, single metal or multiple metal complexes are heated to a temperature whereby, upon contact with hydrogen gas, an exothermic reaction begins. The further temperature rise in response to the exothermic reaction is minimized by reducing the external heat input, thereby minimizing the agglomeration or sintering of the metal nano-scale particles resulting from the process. Preferably, after drawing a vacuum on the metal complexes in the reactor, the hydrogen is introduced at about, equal to or below ambient pressure and the reaction is purposely made slow to prevent agglomeration or sintering.