Ni(Co)-W-B非晶态催化剂的制备和加氢脱氧性能研究
Preparation and catalytic properties of Ni(Co)-W-B amorphous catalysts for 4-cresol hydrodeoxygenation
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摘要: 采用化学还原法制备出非晶态催化剂Ni-W-B和Co-W-B,用BET、XRD和XPS对催化剂进行表征分析,以对甲基苯酚为模型化合物研究了两种催化剂的加氢脱氧性能。结果表明,所制备的两种催化剂均为非晶态结构,两种催化剂在对甲基苯酚的加氢脱氧反应中都显示出较好的脱氧活性。在相对低温523 K下,Ni-W-B催化剂显示较高的加氢活性,转化率达到100.0%,对甲基环己醇的选择性为55.1%,脱氧选择性只有44.1%,而Co-W-B催化剂显示出较高的脱氧活性,脱氧选择性达到93.1%,这主要是由于催化剂的表面不同价态元素组成含量引起的。在573 K和4.0 MPa下,催化对甲基苯酚的加氢脱氧反应的转化率和脱氧选择性都能达到100%。Abstract: Ni-W-B and Co-W-B amorphous catalysts were prepared by chemical reduction. The resulting materials were characterized by BET, XRD and XPS, and the hydrodeoxygenation (HDO) performances of the catalysts were tested using 4-cresol as the model compound. The results showed that both of the two catalysts were amorphous structure. They showed high deoxygenation activity in the HDO of 4-cresol. However, in the HDO of 4-cresol at 523 K, Ni-W-B had high hydrogenation activity, showing 100.0% conversion of 4-cresol, 55.1% selectivity to 4-methylcyclohexanol and 44.1% of selectivity to deoxygenation. Co-W-B showed high activity of deoxygenation and the selectivity of deoxygenation was as high as 93.1%. It was mainly attributed to the different composition content of different elements with different valence states on the surface of the catalysts. Both of 4-cresol conversion and selectivity to deoxygenation could reach 100% over them at the conditions of 573 K and 4.0 MPa of hydrogen.