Texture modifiers (BaO, La2O3, CeO2) and C deposition affectors (K, Mo, W, Mn) were studied in nickel catalysts used to steam-reform n-butane. Al2O3 was modified with 1% BaO or La2O3, impregnated with Ni, and heated at 1000-1200degreesC. Heating at 1100 and 1200degreesC made La2O3 and BaO most effective, resp. With 1% Ce, the active surface of the catalyst before and after heating was resp. 2 and 4 times as great as that of the nonpromoted catalyst. The rate of C deposition decreased as Mo and K contents were increased, 0-0.5 and 0-10%, resp. Their effect rose as the H2O (3) C ratio was raised. At H2O (3) C = 1.5, Mo was 10 times as active as K. At H2O (3) C = 1.2, W (0.8-1.4%) reduced the deposition of C to nil.