Effects of K₂CO₃ on Carbon Deposition Arisen from Decomposition of Butane, and on the Reaction of Butane with Steam, over Supported Nickel Catalysts

Abstract

Effects of K₂CO₃ on the decomposition of butane, and on the reaction of butane with steam, over supported nickel catalysts at 400-500°C were studied.
Addition of K₂CO₃ to the catalysts brought about no effect on the degree of butane decomposition. The composition of carbon deposit, CH_0.2 on the average, at 460°C, obtained by the reaction over the catalysts containing K₂CO₃, did not differ from that without K₂CO₃. On the other hand, in the reaction of butane with steam the activity of the catalysts not containing K₂CO₃ decreased with time. When K₂CO₃ was added, the lapsing decay of catalysts was improved, despite the stationary activity decreased.
These experimental results were explained in terms of the reaction mechanism that butane and water were adsorbed on a nickel surface competitively, and then the reaction occurred between these adsorbed species. It was concluded that when water was absent or the amount of water on the surface was not sufficient, the adsorbed butane might decompose to form carbon deposit.