Summary: | The effect of Cu on Ni in the catalytic transformation of glycerol is strongly governed bythe geometrical effect.In the case of the deep hydrogenolysis which produces CH4, the rupture of the C-Cbond by hydrogenolysis decreases by addition of small amounts of Cu and continues todecrease until CH4 be totally suppressed.As the Ni/Cu atomic ratio decreases the dehydration–dehydrogenation routes starts toprevail, and hydroxyacetone, pyruvaldehyde, lactic acid and pyruvaldehyde areformed.As revealed by XPS results, when the Ni/Cu atomic ratio decreases a progressiveenrichment of Cu in the catalyst surface occurs, decreasing the total number of exposedNi atoms and suppressing totally the deep hydrogenolysis.
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