High-Quality Gasoline Directly from Syngas by Dual Metal Oxide-Zeolite (OX-ZEO) Catalysis

Despite significant efforts towards the direct conversion of syngas into liquid fuels, the selectivity remains a challenge, particularly with regard to high-quality gasoline with a high octane number and a low content of aromatic compounds. Herein, we show that zeolites with 1D ten-membered-ring (10-MR) channel structures such as SAPO-11 and ZSM-22 in combination with zinc- and manganese-based metal oxides (Zn_a Mn_b O_x ) enable the selective synthesis of gasoline-range hydrocarbons C₅ -C₁₁ directly from syngas. The gasoline selectivity reached 76.7 % among hydrocarbons, with only 2.3 % CH₄ at 20.3 % CO conversion. The ratio of isoparaffins to n-paraffins was as high as 15, and the research octane number was estimated to be 92. Furthermore, the content of aromatic compounds in the gasoline was as low as 16 %. The composition and structure of Zn_a Mn_b O_x play an important role in determining the overall activity. This process constitutes a potential technology for the one-step synthesis of environmentally friendly gasoline with a high octane number from a variety of carbon resources via syngas.