Catalytic propane dehydrogenation by anatase supported Ni single-atom catalysts
With the increasing production of propane from shale gas and the growing demand for propylene,propane dehydrogenation(PDH)has gained significant attention as a promising route for the on-purpose production of propylene.As a cheap yet efficient catalyst,Ni-based catalysts have at-tracted interest because of its ability to activate alkane.Single-atom catalysts(SACs)can maximize the metal atom utilization.Here,we demonstrate that anatase TiO2 supported Ni SAC(Ni1/A-TiO2)exhibits not only superior intrinsic activity and propylene selectivity but also much better stability than the corresponding Ni nanoparticle(NP)catalyst(NiNP/A-TiO2)in PDH reaction at 580 ℃.The rate of propylene production on Ni1/A-TiO2 is about 1.96 molC3H6 gNi-1 h-1,about 65 times higher than that of NiNP/A-TiO2 sample(0.03 molC3H6 gNi-1 h-1).In combination of high-angle annular dark-field scanning transmission electron microscopy,in-situ diffuse reflectance infrared Fourier transform spectra,in-situ X-ray photoelectron spectroscopy and X-ray absorption spectroscopy characterizations,we confirm that the Ni SAC mainly contains individual Ni atom singly dispersed on the support in positive Ni(Ⅱ)valence state.In addition,as a result of strong metal-support inter-action(SMSI)between Ni NP and TiO2 carrier under reduced conditions,the Ni NPs sites are en-capsulated by TiOx overlayer(～2 nm thick)thus display poor reaction performance.
Propane dehydrogenationSingle-atom catalystsMetal atom utilizationPropylene selectivityStability
万方数据
