Although considerable progress has been made in direct synthesis gas (syngas) conversion to light olefins (C2(=)-C4(=)) via Fischer-Tropsch synthesis (FTS), the wide product distribution remains a challenge, with a theoretical limit of only 58% for C2-C4 hydrocarbons. We present a process that reaches C2(=)-C4(=) selectivity as high as 80% and C2-C4 94% at carbon monoxide (CO) conversion of 17%. This is enabled by a bifunctional catalyst affording two types of active sites with complementary properties. The partially reduced oxide surface (ZnCrO(x)) activates CO and H2, and C-C coupling is subsequently manipulated within the confined acidic pores of zeolites. No obvious deactivation is observed within 110 hours. Furthermore, this composite catalyst and the process may allow use of coal- and biomass-derived syngas with a low H2/CO ratio.

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Wang and colleagues successfully designed a powerful bifunctional catalyst composed of Zn-doped ZrO 2 nanoparticles and zeolite H-ZSM-5 for one-step conversion of syngas into aromatics. Aromatics with 80% selectivity were obtained at 20% CO conversion. No catalyst deactivation was observed in 1,000 hr. Methanol and dimethyl ether were formed as reaction intermediates on Zn-doped ZrO 2 , which were subsequently transformed into aromatics on H-ZSM-5 via olefins. This work offers a highly selective and stable non-petroleum route for the synthesis of aromatics.