ABSTRACT
Upgrading ethanol to long-chain alcohols (LAS, C6+OH) offers an attractive and sustainable approach to carbon neutrality. Yet it remains a grand challenge to achieve efficient carbon chain propagation, particularly with noble metal-free catalysts in aqueous phase, toward LAS production. Here we report an unconventional but effective strategy for designing highly efficient catalysts for ethanol upgrading to LAS, in which Ni catalytic sites are controllably exposed on surface through sulfur modification. The optimal catalyst exhibits the performance well exceeding previous reports, achieving ultrahigh LAS selectivity (15.2% C6OH and 59.0% C8+OH) at nearly complete ethanol conversion (99.1%). Our in situ characterizations, together with theoretical simulation, reveal that the selectively exposed Ni sites which offer strong adsorption for aldehydes but are inert for side reactions can effectively stabilize and enrich aldehyde intermediates, dramatically improving direct-growth probability toward LAS production. This work opens a new paradigm for designing high-performance non-noble metal catalysts for upgrading aqueous EtOH to LAS.
ABSTRACT
Fe-Based catalysts play crucial roles in Fischer-Tropsch synthesis (FTS). Herein, we for the first time demonstrate a facile sol-gel approach using natural magnetite and citric acid to fabricate porous Fe@C nanohybrids as FTS catalysts. Excellent FTS activity and stability were revealed and attributed to the formation of an Fe3C active phase and a core-shell structure. This flexible synthesis strategy clearly highlights the promising application of such materials in FTS.