Ammonia Decomposition to Hydrogen on Carbon Supported Cobalt Catalysts

摘要

Multi-wall carbon nanotubes (CNTs) and three types of active carbon (AC) were used as supports for cobalt based catalysts. The catalysts were prepared by incipient wetness impregnation method. The activity of the prepared catalysts in ammonia decomposition (AD) was tested in a fixed-bed reactor microreactor. The reaction conditions were as follows: reaction temperature = 400-500°C, pressure = 1 atmosphere and GHSV= 6000 to 24000 h~(-1). The prepared catalysts were characterized by N_2 adsorption-desorption (BET), Transmission electron microscopy (TEM) and CO chemisorption. It was found that for Co/AC catalysts, crystallite size decreased with increasing surface area of the AC support while their activity increased. On the other hand, Co/CNTs catalyst has a much higher activity than the Co/AC catalysts. The higher activity of Co/CNTs is attributed to higher electron donation ability of the CNTs.