Selective Catalytic CO Hydrogenation to Short- and Long-Chain C_(2+) Alcohols

摘要

We show that the CO hydrogenation over CoCu-based catalysts can be tuned so as to produce either short- or long-chain 1-alcohols with high selectivities. This breakthrough is achieved by "alloying" these catalysts with Mn or Mo thereby creating either "CoCuMn" or "CoCuMo" in various relative composition. Catalysts are prepared via co-precipitation of mixed oxalate precursors, except "CoCuMo" for which the co-precipitation of CoCu oxalate is combined with the precipitation of MoO_x using solubility effects. Both "CoCuMn" and "CoCuMo" catalysts produce 1-alcohols or combined 1-alcohols/1-alkenes with selectivities of more than 60% at temperatures between 170 and 240 °C. CoCuMo catalysts show a double Anderson-Schulz-Flory (ASF) chain-lengthening distribution. Under conditions of low CO conversion, the overall selectivity of 1-alcohols may rise to over 95 % for Co1Cu5Mo1 catalysts. The ASF chain-lengthening probability for CO1Cu1Mn1 may be adjusted to ~0.6-0.7 so as to maximize the Cs-C_(14) 1-alcohol slate as feedstock for plasticizers, lubricants or detergents.