Synthesis of Co-based bimetallic nanocrystals with one-dimensional structure for selective control on syngas conversion

Abstract

Co-based bimetallic nanocrystals with one-dimensional (1D) branches were synthesized by the heterogeneous nucleation of Co atoms onto prenucleated seeds, such as Pd or Cu, through a facile wet-chemical route. The peripheral branches (rod-like) of the Co–Pd and Co–Cu nanocrystals were outspread along the (001) direction and were enclosed by (101) facets. By switching the prenucleated metals to form robust Co–Pd or Co–Cu bimetallic nanocatalysts, the selectivity of CO hydrogenation could be adjusted purposely towards heavy paraffins, light olefins or oxygenates. The Anderson–Schulz–Flory chain-lengthening probabilities for products were up to 0.9 over Co–Pd nanocrystals, showing that long-chain hydrocarbons can be formed with high selectivity using the targeted design of Co–Pd nanocrystal catalysts. These Co-based bimetallic nanocrystals with a 1D structure exhibited superior catalytic activities over the corresponding Co-based nanoparticles for synthesis gas conversion.