Low-Temperature Generation of Basic Carbon Surfaces by Hydrogen Spillover

It is demonstrated that stable basic carbons, which will not adsorb oxygen in ambient laboratory conditions, can be created via a relatively low-temperature process. These highly basic carbons are created by treating mixtures of carbons and platinum (in the form of particles supported on a high surface area material) in hydrogen at 500 °C, or even at lower temperatures in some cases. In the absence of platinum, creation of highly basic and stable surfaces with the same starting material requires hydrogen treatments at far higher temperatures (ca. 900 °C). Evidence is presented to support the hypothesis that the role played by platinum (or any noble metal) is to produce atomic hydrogen, which spills over onto the carbon surface. This atomic hydrogen hydrogasifies the most reactive, unsaturated carbon atoms at far lower temperatures than molecular hydrogen, thus leading to surface stabilization at relatively low temperatures.