Catalytic Study for Linear Olefin Formation from Ethanol over Phosphorus-modified Beta-Zeolite Catalysts

Abstract

In this study, we explore the catalytic performance of phosphorus-modified Beta zeolite catalysts for the selective conversion of ethanol to linear olefins, to understand the effects of phosphorus incorporation on the structural, textural, acidic, and hydrophobic properties of the zeolite catalysts, we employed various characterization techniques, such as XRD, N2 physisorption, NH3-TPD, and TGA, the phosphorus-modified Beta zeolites demonstrated enhanced selectivity towards C4-C12 linear olefins, with the P/Beta-5 catalyst (containing 5 wt.% phosphorus) achieving an impressive 72% combined selectivity, we attribute this improved catalytic performance to the moderation of acid site strength and density, as well as the increased hydrophobicity induced by phosphorus modification, these properties effectively suppressed undesired side reactions and promoted the formation of linear olefins through the oligomerization-cracking pathway, we systematically investigated the influence of phosphorus loading and modification method on the catalytic activity, revealing important structure-activity relationships. Based on our experimental findings, we propose a reaction mechanism that highlights the basic role of phosphorus in modulating the reaction pathways, the results of this study give us valuable insights into the design and optimization of phosphorus-modified zeolite catalysts for the efficient and desired production of linear olefins from bio-derived ethanol.