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Abstract

Higher alcohol synthesis (HAS) offers a promising non-petroleum route for producing a variety of compounds relevant to the sustainable energy and chemical production. In this work, we combine experimental and computational studies of CuFe catalysts to identify factors that govern HAS activity and selectivity. Experimentally, we investigate the effects of reaction temperature, catalyst Cu:Fe ratio, and feed gas H2:CO ratio on the conversion and selectivity of CuFe/SiO2 catalysts. The highest selectivity toward higher alcohols is achieved at low temperatures (225–250 degree C), a high Cu:Fe ratio (2:1), and a balanced H2:CO ratio (1:1). Computationally, density functional theory calculations combined with microkinetic modeling are used to examine HAS on a perfectly dispersed 1:1 CuFe(211) stepped surface. Within this model framework, methane formation is predicted to dominate under the conditions considered as a consequence of efficient hydrogenation of CHn intermediates compared to CO insertion and slow O--H bond formation in oxygen-containing intermediates, which favors pathways competing with alcohol production. Together, the experimental and computational results indicate the influence of catalyst composition and reaction conditions on HAS selectivity and suggest that local variations in Cu–Fe arrangement may contribute to balancing chain growth and alcohol formation pathways.