Promoting effect of ruthenium, platinum and palladium on alumina supported cobalt catalysts for ultimate generation of hydrogen from hydrazine

Abstract

The performance of noble metal promoted-Co/γ-Al 2 O 3 bimetallic catalysts was examined for efficient H 2 generation from hydrazine decomposition. Ruthenium, platinum and palladium were chosen as promotor metals (M) to prepare three series of bimetallic catalysts (CoM x /γ-Al 2 O 3 ) via wet impregnation method. Promoting role of each noble metal was studied using various techniques like XRD, AAS, SEM, EDX, N 2 adsorption, H 2 chemisorption, TPR, and TPO. In bimetallic catalysts, all noble metals induced significant promoting effect by increasing H 2 selectivity ~12 times as compared to that of alone Co/γ-Al 2 O 3 catalyst. The catalytic activity was found strongly dependent on both the active metal contents and the type of promoters. The best performance was achieved for CoPt 0.034 /γ-Al 2 O 3 with the lowest activation energy (29.14 kJ mol −1 ) and highest H 2 selectivity (100%) in hydrazine decomposition at room temperature. • Ru, Pt, and Pd are used as the 2nd metal of bimetallic CoM x /γ-Al 2 O 3 catalysts. • Their activity is especially tested for H 2 generation from N 2 H 4 ·H 2 O decomposition. • CoRu 0.11 , CoPt 0.034 , and CoPd 0.093 catalysts exhibit optimal performance at 25 °C. • Superior activity is shown by CoPt 0.034 /γ-Al 2 O 3 catalyst with TOF of 117.8 h −1 . • Alloying Co with a noble metal is the best way to get active bimetallic catalysts.