Recent advances in Co2C-based nanocatalysts for direct production of olefins from syngas conversion.

Abstract

Syngas conversion provides an important platform for efficient utilization of various carbon-containing resources such as coal, natural gas, biomass, solid waste and even CO2. Various value-added fuels and chemicals including paraffins, olefins and alcohols can be directly obtained from syngas conversion via the Fischer-Tropsch Synthesis (FTS) route. However, the product selectivity control still remains a grand challenge for FTS due to the limitation of Anderson-Schulz-Flory (ASF) distribution. Our previous works showed that, under moderate reaction conditions, Co2C nanoprisms with exposed (101) and (020) facets can directly convert syngas to olefins with low methane and high olefin selectivity, breaking the limitation of ASF. The application of Co2C-based nanocatalysts unlocks the potential of the Fischer-Tropsch process for producing olefins. In this feature article, we summarized the recent advances in developing highly efficient Co2C-based nanocatalysts and reaction pathways for direct syngas conversion to olefins via the Fischer-Tropsch to olefin (FTO) reaction. We mainly focused on the following aspects: the formation mechanism of Co2C, nanoeffects of Co2C-based FTO catalysts, morphology control of Co2C nanostructures, and the effects of promoters, supports and reactors on the catalytic performance. From the viewpoint of carbon utilization efficiency, we presented the recent efforts in decreasing the CO2 selectivity for FTO reactions. In addition, the attempt to expand the target products to aromatics by coupling Co2C-based FTO catalysts and H-ZSM-5 zeolites was also made. In the end, future prospects for Co2C-based nanocatalysts for selective syngas conversion were proposed.