Kinetics and mechanism of formation of benzoin ethyl ether from benzaldehyde and ethanol using heterogeneous Ni(HCO3)(2) as catalyst

Ni(HCO3)(2), with a unique phase and high crystallinity, was synthesised utilising urea hydrolysis. The physicochemical properties of the synthetic samples were characterised by X-ray diffraction, scanning electron microscopy and N-2-adsorption desorption measurements. The heterogeneous Ni(HCO3)(2) catalysts presented high catalytic activity in the synthesis reaction of benzoin ethyl ether from benzaldehyde and ethanol. Furthermore, the catalysts could be recycled several times and showed stable activity without structural change. The kinetic parameters were obtained by the half-life law which showed that the reaction was belong first-order. The apparent activation energy was 42.72 kJ mol(-1). The reaction mechanism was probed theoretically using the HF/3-21G method, which suggested that benzoin ethyl ether is formed via a series of states i.e. a complex, transition states and intermediates. Especially, the role of C6H5CHOC2H5OH as an intermediate is significant.