MoVTeNbO_(x) catalysts were prepared through a high-pressure hydrothermal method,in which the crystalline structure and properties of the catalysts were tuned by varying the system pressure(0-12.0 MPa).Results showed ...MoVTeNbO_(x) catalysts were prepared through a high-pressure hydrothermal method,in which the crystalline structure and properties of the catalysts were tuned by varying the system pressure(0-12.0 MPa).Results showed that the system pressure had a significant influence on the structure and catalytic performance of MoVTeNbO_(x).Under 3.0 MPa,MoVTeNbO_(x) prepared possessed the highest content of M1 phase(90.6%)and V5+content(60.7%),exhibiting a uniform short and thick needle-like morphology.Also,it showed excellent selectivity(79.1%)and yield(52.8%)to acrylic acid at the catalytic temperature of 380℃.However,under 4.4 and 11.6 MPa,the characteristic peaks of M1 shifted to a certain extent and the morphology changed from short and thick to slender.As a result,the V5+content of M1(001)plane decreased,resulting in a remarkable decline of the selectivity to acrylic acid.Moreover,DFT simulation results showed that the anti-bond orbital energy of V-O bond is the highest under 3.0 MPa,while further increase of pressure leads to obvious extrusion between atoms in the internal structure of MoVTeNbO_(x).Moreover,it was clear that the lower the anti-bond orbital energy of V-O bond,the lower the selectivity to acrylic acid.展开更多
基金supports by the National Natural Science Foundation of China(no.21706165)Natural Science Foundation of Liaoning Province,China(no.2021-MS-255)+1 种基金LiaoNing Revitalization Talents Program(no.XLYC2002001)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program,China(no.RC210184).
文摘MoVTeNbO_(x) catalysts were prepared through a high-pressure hydrothermal method,in which the crystalline structure and properties of the catalysts were tuned by varying the system pressure(0-12.0 MPa).Results showed that the system pressure had a significant influence on the structure and catalytic performance of MoVTeNbO_(x).Under 3.0 MPa,MoVTeNbO_(x) prepared possessed the highest content of M1 phase(90.6%)and V5+content(60.7%),exhibiting a uniform short and thick needle-like morphology.Also,it showed excellent selectivity(79.1%)and yield(52.8%)to acrylic acid at the catalytic temperature of 380℃.However,under 4.4 and 11.6 MPa,the characteristic peaks of M1 shifted to a certain extent and the morphology changed from short and thick to slender.As a result,the V5+content of M1(001)plane decreased,resulting in a remarkable decline of the selectivity to acrylic acid.Moreover,DFT simulation results showed that the anti-bond orbital energy of V-O bond is the highest under 3.0 MPa,while further increase of pressure leads to obvious extrusion between atoms in the internal structure of MoVTeNbO_(x).Moreover,it was clear that the lower the anti-bond orbital energy of V-O bond,the lower the selectivity to acrylic acid.
