Development of Mo x Ru y Se z (CO) n electrocatalysts by screen printing and sintering for fuel cell applications

Abstract

Electrocatalysts based on molybdenum, ruthenium, and selenium were prepared by screen printing Ru₃ (CO)₁₂ + Se and Ru₃ (CO)₁₂ + Mo(CO)₆ + Se mixtures and subsequent sintering at 250°C in air or Se atmosphere in a tubular furnace. The catalysts were characterised using techniques such as XRD, SEM, TEM, voltammetry, and polarisation (current–potential) measurements. The results indicate that screen printed Ru_x Se_y (CO)_n and Mo_x Ru_y Se_z (CO)_n are near amorphous in nature and possess appreciable catalytic activity for the oxygen reduction reaction in a polymer electrolyte (Nafion membrane) fuel cell. The electrocatalytic activity seems to diminish with selenium incorporation in the lattice of the carbonyl clusters formed during synthesis.