Alkaline water electrolysis is hindered by the slow kinetics of the hydrogen evolution reaction (HER) in alkaline media. We report enhanced HER activity of Pt on a mixed-metal-oxide support composed of titanium dioxide (TiO2) and ruthenium dioxide (RuO2). The Pt/RuO2-TiO2 (Pt/RTO) electrocatalyst was characterized by XRD, TEM and BET. The particle size of Pt was 6 +/- 0.63 nm and the support surface area was 33 +/- 1.15 m(2)/g. The activity of Pt/RTO toward HER and the hydrogen oxidation reaction (HOR) in 0.1 M KOH was compared against a benchmark Pt/C catalyst (46.5% Pt; Tanaka, K. K.) using the rotating disk electrode (RDE) technique. Pt/RTO outperformed the benchmark Pt/C over the range of temperatures studied (275-313 K). The exchange current density for Pt/RTO was 2.31 +/- 0.06 mA/cm(2) Pt (at 295 K, 1600 rpm, in H-2-saturated 0.1 M KOH), which was more than five times the measured exchange current density of the Pt/C benchmark under the same conditions. Pt/RTO and Pt/C were further evaluated in a solid-state alkaline water electrolyzer operated with ultrapure water. MEAs fabricated with Pt/RTO as the cathode and IrO2 as anode catalyst showed a 100-200 mV reduction in the cell voltage across the entire current density range, when compared to MEAs fabricated with Pt/C at the cathode and IrO2 at the anode. (C) The Author(s) 2017. Published by ECS. All rights reserved.