Core-shell structured Ru-Ni@SiO2: Active for partial oxidation of methane with tunable H2/CO ratio

This study demonstrated that a Ru-Ni bimetallic core-shell catalyst (0.6% Ru-Ni)@SiO2 with a proper surface Ru concentration is superior in achieving better catalytic activity and tunable H-2/CO ratio at a comparatively lower reaction temperature (700 degrees C). Compared to the impregnation method, the hydrothermal approach leads to a highly uniform Ru distribution throughout the core particles. Uniform Ru distribution would result in a proper surface Ru concentration as well as more direct Ru-Ni interaction, accounting for better catalyst performance. Enriched surface Ru species hinders surface carbon deposition, but also declines overall activity and H-2/CO ratio, meanwhile likely enhances Ni oxidation to certain degree under the applied reaction conditions. Over the current (m % Ru-Ni)@SiO2 catalyst, the formation of fibrous carbon species is suppressed, which accounts for good stability of catalyst within a TOS of 10 h. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.