The Effect of the Ruthenium Crystallite Size on the Activity of Ru/Carbon Systems in CO Methanation

Abstract

The influence of the ruthenium crystallite size on the catalytic activity of Ru/graphitized carbon systems in carbon monoxide methanation was evaluated. Four graphitized carbon materials differing in their surface area were used as supports for Ru. The average size of Ru crystallites in Ru/C materials was estimated by X-ray powder diffraction, transmission electron microscopy and CO chemisorption. Dispersion of the active phase clearly depends on the carbon texture. The activity tests conducted in H2-rich streams with very low CO concentrations (0.5 vol% CO) have shown that the activity of Ru/carbon catalysts changes with the ruthenium particles size (d). The highest activities were obtained for ruthenium particles in the range 4–8 nm in size.