129.    -------------. [BAHR, H. A.] [Reduction of Carbonic Acid.]   Ges. Abhandl. Kenntnis Kohle, vol. 8, 1929, pp. 219-224; Chem. Zentralb., 1930, I, p. 185; Chem. Abs., vol. 24, 1930, p. 5207.

                  Reduction of CO₂ according to CO₂+H₂=CO+H₂O, which up to the present has been investigated only at relatively high temperatures, can be carried out also at moderate temperature if the proper catalysts are employed.  With metallic Cu the reaction is noticeable at 200°.  With the employment of Cu·Cr₂O₃Fe·Cu, Fe·CO and Co·Cu·Zu as contact materials with temperatures between 200° and 450° and with mixtures of CO₂ and H₂ in the ratio 1:1 and 1:3, respectively, the CO quantities obtained were up to 16%.  With a slow current of the gas mixture, reduction of CO to CH₄ occurred, especially when contacts containing Co were employed.