No abstract

Methanol is a key reaction intermediate formed on MnOx that synergistically reacts with SAPO-34 to produce light olefins.

Bifunctional MnO x + SAPO-34 catalysts were evaluated for the conversion of syngas to light olefins (OXZEO process). They were prepared, either by mechanical mixing of 100 μm-scale particles agglomerates, or by mixing of ethanol suspensions, containing homogeneously distributed micrometer-scale primary particles of oxide and zeolite. The selectivity to light olefins, initially lower for the mechanical mixture, reached the value of the suspension mixture after a 14 h on-stream period.This convergence was explained from SEM images by in situ breaking of SAPO-34 agglomerates present in the mechanical mixture and dispersion of SAPO-34 crystals among MnO x primary particles, decreasing the contact distance between the two catalytic functions. These results evidence the importance of intimacy at the micrometer scale to improve the catalytic properties in the OXZEO process.