Selective synthesis of 1-octene from ethylene oligomerization using new structure of MOF(chromium-based MOFs, boron co-catalysts and ligand)

Linear α-olefins (LAOs), particularly 1-octene, are key intermediates in polyolefin chemistry, motivating the development of advanced catalytic materials capable of controlled and selective ethylene oligomerization. In this study, a series of chromium-based metal–organic frameworks (MOFs) are rationally designed and investigated as engineered heterogeneous catalysts, with particular emphasis on improving 1-octene selectivity through framework-level control. Ten structurally distinct chromium containing MOFs incorporating polydentate phosphorus and nitrogen donor ligands were synthesized and systematically evaluated in the presence of boron based cocatalysts. By integrating chromium active centers, ligand environments, and cocatalyst species within a single MOF architecture, clear correlations between framework structure, coordination environment, and catalytic behavior were established. Cooperative interactions arising from the spatial proximity of ligand motifs and cocatalyst sites were found to enhance catalytic activity, suppress polyethylene formation, and promote linear oligomerization pathways. Notably, MOF10, featuring a distinct coordination environment and three-dimensional framework architecture, exhibits significantly enhanced selectivity toward 1-octene relative to 1-hexene under optimized reaction conditions. These results demonstrate that rational MOF design provides an effective strategy for improving 1-octene selectivity and offer valuable insights into structure–selectivity relationships for the development of next-generation ethylene oligomerization catalysts.