Boosting Dehydration via Coupling With the Water-Gas Shift Reaction

To address the challenge of removing water from dehydration reactions when reaction components share similar physical properties with water, we developed a reaction coupling strategy that integrates dehydration with the water-gas shift (WGS) which was enabled by the Pt/hydrophobically modified Al-SBA catalyst (Pt/Al-SBA-C₁₂). Through quasi in situ characterizations and molecular dynamics simulations, the dynamic evolution process of water generation, transport, and activation has been elucidated. At the Lewis acid sites on the hydrophobic SBA surface, lactic acid, and alcohol molecules react to form esters and water. Subsequently, driven by the wettability gradient, water molecules undergo directional transport from the SBA surface to the Pt sites within 7.5 ns, accompanied by the induction of contact electrification. The dissociated ^*OH over Pt sites further reacts with adsorbed CO to form an ^*COOH intermediate, ultimately producing CO₂ and H₂. Leveraging this system, the Pt/Al-SBA-C₁₂ catalyst achieves a lactic acid conversion of 96.1% in the coupled reaction, substantially higher than the 52.3% attained by unmodified Pt/Al-SBA under standalone esterification conditions. Moreover, the Pt/Al-SBA-C₁₂ catalyst maintains stable performance over at least 10 cycles. With broad substrate applicability, our approach enables water removal without relying on differences in physical properties, showing great potential for practical applications.