Understanding the Selective Adsorption of Phenol From Simple Mixture to Model Biofuel. Contribution of ATR‐IR Spectroscopy

ABSTRACT The selective removal of oxygenates like phenol is a key challenge in upgrading biofuels. This study evaluates the adsorption performance and selectivity of zeolites (HY2.9, USY22, and USY40) and oxides (Al 2 O 3 , SBA‐15) for phenol in the presence of fuel representative co‐molecules (toluene, cyclohexane, and 2,3‐dimethyl‐2‐butene) using batch experiments and, notably, operando ATR‐IR spectroscopy. Batch adsorption capacities followed the order SBA‐15 > HY2.9 > USY40 ≈ USY22 > Al 2 O 3 . Performance depends on a combination of factors such as specific surface area, pore size and pore density, as well as the density and nature of the acid sites. While cyclohexane had negligible impact, toluene and dimethylbutene induced competitive adsorption or site poisoning, with effects being nearly cumulative in complex mixtures. ATR‐IR measurements not only corroborated batch trends but also provided molecular‐level insights, demonstrating its relevance as a rapid, operando screening tool to assess adsorption mechanisms, selectivity, and regeneration potential with minimal material consumption. The findings highlight the advantage of weakly acidic or non‐acidic adsorbents in complex mixtures and underscore the utility of ATR‐IR for efficient adsorbent evaluation.