Hydrophobic Fe‐Based Catalyst Derived from Prussian Blue for Enhanced Photothermal Conversion of Syngas to Light Olefins

Abstract Although there are many promising works in the field of Fischer–Tropsch synthesis (FTS), it is still a huge challenge to achieve the rational design of FTS catalysts for excellent selectivity toward light olefins with a high olefins/paraffins ratio (o/p ratio). Herein, a hydrophobic core–shell Fe‐based FTS catalyst is developed by calcination and hydrophobic modification of polyvinylpyrrolidone (PVP)‐decorated Prussian blue (PB, Fe₄[Fe(CN)₆]₃) precursor. The hydrophobic modification is achieved by using trimethylchlorosilane (TMCS) as the hydrophobic agent. Under light irradiation and near ambient pressure (0.18 MPa), compared with the catalyst without the hydrophobic surface to mainly convert CO to valueless CO₂, the optimal catalyst delivers excellent selectivity of 48.0% for value‐added light olefins (C_2–4 ⁼ ) with a high o/p ratio of 10.1 but low selectivity for CO₂ at a CO conversion of 22.6%. The excellent FTS performance can be attributed to that the hydrophobic surface of the catalyst regulates the chemical reaction pathway, which promotes the CO hydrogenation but suppresses the conversion of CO to CO₂. The study demonstrates that a rationally designed functional surface of a catalyst can govern the reaction pathway along value‐added solar‐to‐chemicals conversion.