Study on Cu-Mn-Si catalysts for the coupling process of cyclohexanol dehydrogenation and furfural hydrogenation：Effect of pH value and calcination temperature

The coupling process of the cyclohexanol dehydrogenation and the furfural hydrogenation on precipitated Cu-Mn-Si catalysts was carried out at atmospheric pressure in gas phase. The effects of pH value and calcination temperature on the performance of catalysts were studied in detail. There was no observable difference in furfural hydrogenation reaction over the catalysts precipitated at different values of pH. However, pH value had significant influence on the selectivity of cyclohexanone. The catalysts precipitated at the pH values range of 7.5 to 10.0 showed good performance for the coupling process. The increase of calcination temperature decreased the surface area and copper surface area and increased the average pore size, leading to a difficult reduction of the active phase. The calcination temperature had no significant effect on the cyclohexanol dehydrogenation to cyclohexanone, whereas the conversion of furfural and the selectivity of 2methylfuran declined with the increase of calcination temperature.