In Situ Reduced Ni–Sn Bimetallic Catalyst for Enhancing Direct Upgrading of Aqueous Ethanol to Higher Alcohols

Direct coupling of aqueous ethanol is an important route for the synthesis of higher alcohols as jet fuels or plasticizer precursors. In this work, the effect of the catalyst chemistry state on the activity of the ethanol coupling was investigated over NiSnH catalysts under various gas atmospheres and pretreatment temperatures. Experimental investigations and characterizations indicate that the reaction atmosphere affects the metal valence of the catalyst during the in situ reaction process, the metal monomers prereduced from the catalyst precipitate and dissolve during the reaction, and the NiSnH catalysts without pretreatment retain sufficient active sites by reducing the NiSn alloy in situ during the reaction. Generally, our experiments confirm theoretical insights into a clear and correlative dependence between measured activity and chemical composition.