Dispersion and hydrogenation property of nano-Ni in ethanol solution in a stirring tank reactor

Abstract This work presents the dispersion of nano-Ni in the ethanol solution in a stirring tank reactor (STR). The effects of different operating conditions, such as stirring speed, volume fraction of cinnamaldehyde (CAL), stirring time, temperature, pH and nano-Ni concentration, on the dispersion effect of nano-Ni into the ethanol solution in the STR were investigated to optimize the operating conditions during the dispersion process. Also, the dispersing mechanism of this process was studied. The experimental results indicated that the average particle size of the dispersed nano-Ni ( D N ) decreased with an increase of stirring speed, volume fraction of CAL, stirring time, temperature and nano-Ni concentration and the D N was smaller at acidic or alkaline condition than neutral condition. The dispersed nano-Ni with a D N of 2.07 μm was obtained under the optimal operating conditions of a nano-Ni concentration of 0.01 g/mL, a stirring speed of 1500 rpm, a stirring time of 2 h, a temperature of 403 K and a pH of 13. The catalytic hydrogenation results indicated that a better dispersion effect of nano-Ni in the liquid could improve the conversion of CAL and the selectivity of HCAL. The study can provide a route to reduce the agglomeration of nano-Ni which is benefit to the catalytic effect in the nano-catalysis process.