Using Pt microelectrodes in liquid ammonia for studying proton reduction

The electrical response of Pt microelectrodes, with a radius of 10 mu m, wa s studied in liquid ammonia (- 50 degrees C). The question of a suitable tu ne stale for steady state measurements in liquid ammonia is important. The proton reduction currents were measured for different scan rates. A suitabl e experimental time scale of 20 mV s (-1) was determined to reach a station ary state. The diffusion coefficient of protons in liquid ammonia was deduc ed from these electrochemical results: D(NH4+)(NH3) = (3.8 +/- 0.4) x 10(-9 ) m(2) s(-1) . (C) 1999 Elsevier Science S.A. All rights reserved.