Carbon nanotube-supported copper-cobalt catalyst for the production of higher carbon number alcohols through carbon monoxide hydrogenation

A series of carbon nanotube (CNTs)-supported copper-cobalt catalysts were prepared and investigated in a slurry reactor for their ability to selectively convert syngas into higher carbon number alcohols. The 7.5Cu7.5Co/CNTs catalyst achieved superior selectivity towards the formation of ethanol (30.1%) and C₂₊ alcohols (57.7%), while the 10Co5Cu/CNTs catalyst exhibited the largest alcohol space-time yield (372.9 mg g_cat^-1 h^-1). However, the pure Cu (¹⁵Cu/CNTs) catalyst displayed negligible activity. Cobalt reduction was enhanced in the presence of copper. In addition to the Cu⁰-Co⁰ center, Co⁰ -Co²⁺ also presented dual active sites for higher alcohols synthesis, the Co²⁺ site could terminate carbon chain growth to produce alcohols. The ratio of Cu/Co considerably influences the metal particle properties-synergistically effecting the active species. (author)