Tailored Fe catalyst microenvironment for highly efficient syngas conversion to olefins with low CO₂ emissions

Achieving highly efficient syngas conversion to olefins on the Fe-based catalysts is promising, but remains a big challenge due to the twin coexistence of the Fischer-Tropsch to olefins (FTO) and water gas shift (WGS) reactions. Herein, we developed a strategy via regulating the microenvironment of Fe catalyst and controlling the diffusion behaviors of critical intermediates to successfully realize the syngas conversion to olefins with low CO₂ emission. A Fe@C catalyst with Fe species encapsulated in porous carbon was fabricated and achieved high single-pass olefins yield (>30%) and low CO₂ selectivity (around 20%) simultaneously, which has ranked the top among the ever-reported advanced oxide-zeolite, Co-based, and Fe-based catalysts. A series of experimental and theoretical results revealed that the unique microenvironment could enrich olefins and inhibit hydrogenation reaction, therefore favoring high value-added olefins formation. Moreover, due to the accelerated diffusion of H₂O molecules, the WGS side reaction was obviously inhibited even at high CO conversion. Our research presented a new catalyst design strategy to realize highly efficient and controllable catalysis in syngas conversion.