In-situ formaldehyde-driven synthesis of renewable isoprene from methanol and isobutene via oxidative-Prins reaction over rare-earth lanthanum-tuned Mo-Fe-O multifunctional catalysts

Le résumé fourni par la source

A single-phase lanthanum-modified Mo-Fe-O catalyst enables efficient and selective oxidative-Prins reaction for renewable isoprene synthesis from bio-methanol and isobutene. Compared to prior composite catalysts ( e.g. , Mo-Fe-O + Cu/MgO or Mg(OH) 2 ), it integrates redox and acidic-basic sites into one phase without physical mixing. La modification significantly enhances Fe 2 (MoO 4 ) 3 and MoO 3 active phases, increases oxygen vacancies, optimizes the surface Mo/Fe ratio, and enhances the synergy between redox and acidic-basic sites. This promotes methanol oxidation to formaldehyde and the subsequent Prins condensation with isobutene, while suppresses over-oxidation to CO x . The optimized 2Mo-Fe-0.1La-O catalyst achieves ~90 % methanol conversion and ~ 93 % isoprene selectivity even at lower temperatures. It exhibits good recycling stability, with isoprene selectivity remaining ~92 % after five successive regenerations. Comprehensive characterization results reveal that La modification enhances methanol conversion by promoting methoxy intermediates convert to formaldehyde and the timely desorption of formaldehyde to prevent them being over-oxidized, while also lowering the energy barrier for isobutene α-H abstraction and accelerating proton transfer in Prins condensation.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.