[Ni(en)3](NO3)2 as precursor to synthesis of highly dispersed Ni on HMS for the catalytic of 1, 2-cyclohexanediol to catechol

A bimetallic Ni-Pt catalyst (6Ni-Pt-HMS) was designed for the dehydrogenation of 1,2-cyclohexanediol (CHD) to catechol. The hexagonal mesoporous silica (HMS) as support, loaded with platinum and nickel by one-pot and incipient-wetness impregnation method, respectively. [Ni(en)3](NO3)2 is used as the precursor of nickel. The physi-cochemical properties of the catalysts were examined by XRD, BET, SEM and TEM techniques. The effect of ethylenediamine on nickel dispersion during impregnation was studied by comparing with the traditional precursor (nickel nitrate). FTIR and TGA results showed that the presence of ethylenediamine modifies the behavior of nickel during impregnation and calcination. The activity and stability of the catalysts were evaluated on a fixed-bed, revealing the influence of mesoporous structure, ethylenediamine, and platinum on reaction. The 6Ni-Pt-HMS catalyst, with the conversion of CHD is 100 %, the selectivity of catechol as high as 99.7 % with the liquid hourly space velocity (LHSV) is 9 h−1, and a long-term stability. The deactivation mechanism of the spent catalyst was analyzed by BET, TGA, SEM, TEM-EDX and ICP-OES.