Selective oxidation of ethanol towards a highly valuable product over industrial and model catalysts

Background: Industrial production of a highly versatile chemical derived from biomass valorization, 1,1-diethoxyethane (DEE), is practically carried out via two consecutive steps involving ethanol partial oxidation followed by condensation/dehydration of ethanol with previously obtained acetaldehyde. Developing a selective bifunctional catalyst for a one- pot synthesis of DEE is of considerable interest, helping to economize production costs and minimize environmental impacts. Activities of the model rhenium (Re) catalysts supported on TiO2 and Al2O3 with those of two industrial catalysts amorphous Mo12V3W1.2Cu1.2Sb0.5Ox and crystalline MoO3-Fe-2(MoO4)(3)) in the single-step gas-phase selective oxidation of ethanol were evaluated. Results: A comparison of chosen catalytic performances is reported. The effects of the reaction parameters, including the gas hourly space velocity, oxygen-to-ethanol ratio and temperature on the catalytic activities over the amorphous Mo-based catalyst were also discussed. The Re supported on TiO2 and amorphous Mo-based catalysts exhibited promising catalytic performances, resulting in the best productivity ever reported by far in the literature of 0.7 kg(DEE) kg(cat)(-1)h(-1). Conclusion: Besides the remarkable productivity achieved from the model Re-based and industrial Mo-based catalysts, the results obtained from this study can be used as a basis for an improvement in the percentage yield in DEE or its productivity, by optimizing both the catalyst formulations, analogous to what have been chosen here, and the catalytic conditions which are adaptable to industrial scales.