Bio-ethanol dehydrogenation to acetaldehyde over (NC)Li-Al oxide supported copper catalyst

Acetaldehyde is widely required in a number of industrial chemistry sectors and commonly prepared by Wacker process which is non-ecological and costly. Utilizing bio-ethanol as a feedstock for acetaldehyde represents eco-friendly and sustainable procedure that decreases fossil resource demand. Here, acetaldehyde is synthesized from ethanol by heterogeneous catalysis on target (NC)Cu/Li-Al oxide catalysts. A series of Li-Al oxide supports with different synthetic Li/Al ratios were prepared from layered double-hydroxide precursors. Copper was introduced using melamine-assisted impregnation at concentrations of 0.6, 2, and 10 wt %. The (NC)Cu/Li-Al oxide catalysts are applied in the non-oxidative dehydrogenation of ethanol for the first time. The characterization methods described variable textural, morphological, redox and acidobasic catalyst properties. Catalytic experiments were realized in a flow reactor at atmospheric pressure, in the temperature range of 180 – 380 °C. The most active was the catalyst with the highest lithium content and 10 wt % Cu, which at a temperature of 300 °C and a WHSV of 1.1 h−1 showed an ethanol conversion of over 80 % and a selectivity to acetaldehyde of 99 %. The stability of the catalyst was evaluated as above average, and the selectivity to acetaldehyde was high over a wide temperature range.