The removal of CO from reformate streams by selective CO methanation was investigated over TiO2 supported Ru-Ni bimetallic and monometallic catalysts. The combination of Ru and Ni enhanced CO methanation at low temperatures. The introduction of Ni into Ru/TiO2 decreased the CO2 conversion rate at 260 degrees C from 10 to 7.3 mu mol min(-1) g(cat)(-1). The use of Ru and Ni, thus, expands the temperature range of selective CO methanation. Transmission electron microscopy and temperature programmed reduction by H-2 confirmed that Ru species were in close proximity to Ni species on Ru-Ni/TiO2, indicating a decrease in direct contact between Ru and TiO2. Fourier transform infrared spectroscopy techniques revealed that the decomposition of the formate species, formed during CO2 methanation, is slow over Ru-Ni/TiO2, in contrast to Ru/TiO2. (C) 2013 Elsevier B.V. All rights reserved.