In situ generation of intimacy in MnOx+SAPO‐34 mechanical mixture for the conversion of syngas to light olefins

Bifunctional MnOx+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 MnOx 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.