Engineering Specific Mo–O Bond Stretching to Activate Lattice Oxygen in V-Doped Bi<sub>2</sub>MoO<sub>6</sub> for Enhanced Oxidative Dehydrogenation of 1-Butene
Qinyang Zhao, Xinglin Hou, Jinling Wang, Dang‐guo Cheng, Fengqiu Chen, Xiaoli Zhan
Abstract
Structural distortion has been demonstrated to regulate lattice oxygen activity, but its precise regulation has always been a thorny problem, especially for the oxidative dehydrogenation of hydrocarbons. Herein, by synthesizing a series of V-doped Bi2MoO6 catalysts, mechanistic insight into the effect of structural distortion on the catalytic activity of oxidative dehydrogenation of 1-butene was provided. Comprehensive characterizations and kinetics tests revealed that the V-doped Bi2MoO6-induced active lattice oxygen initiates 1-butene activation by abstracting the C–H bond, which is a rate-determining step. Combined with density functional theory results, an overwhelming effect of the bond length between Mo and apical oxygen atom in the MoO6 octahedron on lattice oxygen activation and butadiene formation pathway was proposed. The stretching Mo–Oapical bond elicited by V doping enhances the abstraction of hydrogen and accelerates the redox cycle. The sample with a 5% V content possesses the maximum Mo–Oapical bond length, enabling superior catalytic performance at an 87.6% 1,3-butadiene yield.