Realizing high conversion of syngas to gasoline-range liquid hydrocarbons on a dual-bed-mode catalyst

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Achieving high conversion of syngas to fuels and basic chemicals with excellent selectivity and stability remains a challenge. Here, we report an 80.6% selectivity of gasoline-range C 5–11 hydrocarbons at 86.3% CO conversion over a dual-bed catalyst (CZA + Al 2 O 3 )/N-ZSM-5(97) that consists of an upper-bed syngas-to-dimethyl ether (DME) catalyst (CZA + Al 2 O 3 ) and a lower-bed DME-to-gasoline catalyst (nano-sized N-ZSM-5(97) zeolite). This dual-bed catalyst exhibits an excellent stability in a 110-h reaction test. The iso / n -paraffin ratio in the C 5–11 is up to 18. For the lower-bed zeolite catalyst, the nano-sized structure is beneficial to reduce coke and prolong lifetime; meanwhile, the low acid content is advantageous to increase C 5–11 selectivity. The 2,3-dihydro-1H-inden-1-one species can be definitely detected and identified in the spent lower-bed micro-sized M-ZSM-5(18) catalyst. They are regarded as intermediates to generate polycyclic aromatics, which generally lead to catalyst deactivation. The dual-bed catalyst (CZA + Al 2 O 3 )/N-ZSM-5(97) suggests a promising application in producing gasoline from syngas. • High and selective conversion of syngas to gasoline is achieved by a dual-bed catalyst • The dual-bed catalyst contains upper CZA + Al 2 O 3 and lower N-ZSM-5(97) catalysts • Nano-sized structure of N-ZSM-5(97) is beneficial to reduce coke and prolong lifetime • The low acid content of N-ZSM-5(97) helps to increase gasoline selectivity Because of the gradual depletion and non-renewability of petroleum, the use of non-petroleum resources instead of petroleum is of great significance. This alternative route can be generally achieved through syngas chemistry. The primary transportation fuel gasoline, which contains hydrocarbons with 5–11 carbons and is now almost derived from petroleum, can also be produced from non-petroleum syngas by some methods. However, stably obtaining high gasoline selectivity at high syngas conversion is still challenging. We have achieved this goal by designing a dual-bed catalyst (CZA + Al 2 O 3 )/N-ZSM-5(97) that includes a syngas-to-dimethyl ether (DME) catalyst CZA + Al 2 O 3 in the upper bed and a DME-to-gasoline catalyst N-ZSM-5(97) in the lower bed. This dual-bed catalyst suggests a promising application in producing gasoline from syngas. An 80.6% selectivity of gasoline-range hydrocarbons at 86.3% CO conversion can be achieved over a dual-bed catalyst that consists of a syngas-to-DME catalyst CZA + Al 2 O 3 (a mixture of CuZnAl methanol synthesis catalyst and acidic γ-Al 2 O 3 catalyst) in the upper bed and a DME-to-gasoline catalyst N-ZSM-5(97) (nano-sized H-ZSM-5 zeolite with Si/Al ratio = 97) in the lower bed. The dual-bed catalyst suggests a promising application in producing gasoline from syngas.