Preparation of high-surface-area Ni/CaO catalyst with citric acid and its application to MIBK synthesis

CaO-C catalysts were prepared by precipitating calcium acetate with citric acid for 4 h in an aqueous solution at 80 degreesC followed by reduction at 500-700 degreesC. The resultant average pore radius and BET surface area of CaO-C, CaO crystallite size, and carbon content in CaO-C were about 1.5-3.5 nm, 170-200 m(2)/g, 11.2 nm, and 10-20%, respectively. These values suggest that the highly dispersed CaO-C catalyst Forms mainly due to the residual carbon acting as a spacer. 4 wt% Ni/CaO-C reduced at 700 degreesC was used for one step synthesis of methyl isabutyl ketone (MIBK) from acetone, 60-70% of acetone overall conversion and 70% of MIBK selectivity are obtained which are much higher than those ever reported. The diisobutyl ketone (DIBK) selectivity decreases drastically because of the remaining carbon which blocks DIBK formation sites.