Rape Pollen-Templated Synthesis of C,N Self-Doped Hierarchical TiO2 for Selective Hydrogenation of 1,3-Butadiene

Herein, we described a mild and facile method for the synthesis of three-dimensional (3D) hierarchically porous TiO2. This method simultaneously realized the C,N self-dopant, introduced more surface defectives, and decreased in the band-gap energy (Eg) of TiO2. Rape pollen was chosen as the biotemplate to prepare TiO2, and the pore property of the obtained products could be adjusted by changing the amount of Ti precursor and calcination temperature. The as-synthesized pollen-TiO2 not only duplicated the morphology of rape pollen, but also showed enhanced 1-butene selectivity in the reaction of selective hydrogenation of 1,3-butadiene after loading elemental Pd, when comparing with the commercial TiO2. Butenes selectivity of 98% and 1-butene selectivity of 66% were achieved at 50 °C, because of the hierarchically porous structure of pollen-TiO2 and the lower Eg and more surface defects resulting from the C,N dopant.