3340.     TAYLOR, H. S., AND NEVILLE, H. A.  Catalysis in the Interaction of Carbon With Steam and With Carbon Dioxide.  Jour. Am. Chem. Soc., vol. 43, 1921, pp. 2055-2071; Chem. Abs., vol. 16, 1922, p. 522.

        Steam was passed over C at 490°, 525°, and 570° and the volume, and composition of the gases evolved were determined both in the presence and absence of catalysts.  The reaction is (a) C+H₂O=CO₂+H₂.  The amount of CO in the emergent gases was hardly measurable.  This reaction takes place in 2 steps (b) C+H₂O=CO+H₂ and (c) CO+H₂O=CO₂+H₂, of which (c) is the slower.  Good catalysts for (c) such as Fe oxide do not affect the velocity of (a); hence (c) reaches equilibrium under these conditions even in the absence of catalysts.  Many substances of which K₂CO₃ is best are powerful catalysts for (a).  The same substances are found to catalyze the reaction (d) C+CO₂=2 CO.  Adsorption measurements show that these catalysts increase the adsorption of CO₂ by charcoal.  The results conform to the view that a surface complex C_xO_y is formed and the catalysts hasten the decomposition of this complex, thus cleaning off the surface for further adsorption of CO₂.